The genus Cyclocephala Dejean, 1821 (Melolonthidae: Dynastinae) is morphologically characterized by the absence of prominent tubercles or horns on the head or pronotum, and differs from other genera of Cyclocephalini, in addition to the convergent shape of the clypeus and the quite variable apex. With over 350 described species, it is predominantly distributed in the Nearctic and neotropical regions, the latter being the most diverse. The genus's great diversity leads to the formation of species groups based on morphological similarities to facilitate their taxonomic study. Among these, the Cyclocephala latericia species group originally consisted of three species, characterized by yellowish-brown body coloration, the presence of six pronotal spots, and a pygidium with long bristles. However, these species present significant taxonomic challenges due to the great similarity in their morphological structures, such as the male genitalia. The main objective of this work was to revise and update the taxonomy of the Cyclocephala latericia species group. The study was developed at the Insect Taxonomy Laboratory (LabTaxIn) of UFRPE, based on the morphological analysis of specimens from various entomological collections. As a main result, it was identified that the group is considerably more diverse than previously known. Nine new species, potentially new to science, were recognized, raising the total to twelve species within 58 this group, with the vast majority of them distributed along the dry diagonal of South America. For each species, a diagnosis and morphological description were provided, in addition to the following resources: a dichotomous taxonomic key, detailed illustrations, and a map of geographic distribution, fundamental tools for correct identification and for future ecological and taxonomic studies.

Sugarcane is one of the main agricultural crops in Brazil, particularly in the Northeast region, where it plays a major socioeconomic role. One of the main production constraints is losses caused by the stem borer complex, especially Diatraea impersonatella (Walker) and Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), which reduce agro-industrial yield and facilitate the occurrence of phytopathogens. Due to the cryptic behavior of these pests, biological control represents the main management method, with emphasis on the use of egg and larval parasitoids. In this context, the pupal parasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) emerges as a promising complementary control, acting on the pupal stage of lepidopteran pests. This study evaluated the effect of temperature, the main abiotic factor, on the biological performance of T. howardi. Given the expectation of increasingly frequent thermal stress events, the potential of thermal stress as a physiological preconditioning strategy for the parasitoid was investigated. Controlled thermal stress was applied at different developmental stages of T. howardi, aiming to increase survival without impairing parasitism capacity under semi-field conditions. The results demonstrated that controlled thermal stress can act as a physiological preconditioning strategy in T. howardi, enhancing survival while maintaining parasitism performance under semi-field conditions, as long as the critical thermal limits and the ontogenetic stage of the parasitoid are respected.

Modern agriculture seeks to balance food security and sustainability; however, conventional pest control methods are limited by resistance and damage to non-target organisms. Integrated Pest Management (IPM) incorporates selective tools, such as biological control, which utilizes natural enemies to regulate pest populations. Nevertheless, these agents are often negatively impacted by chemical insecticides. A promising alternative to mitigate such effects is RNA interference (RNAi) technology. RNAi is a conserved cellular mechanism that promotes sequence-specific gene silencing by degrading messenger RNA. In agriculture, it can be applied via genetically modified plants or through topical applications. For instance, SmartStax® PRO corn expresses dsRNA targeting the Snf7 gene of Diabrotica virgifera virgifera. This highly conserved gene encodes a vital protein of the ESCRT-III complex, essential for cellular trafficking. Although RNAi effectiveness is based on sequence identity between the dsRNA and the target mRNA, effects on natural enemies exposed to dsRNA designed for a specific pest cannot be ruled out and must be verified. Predators such as the lady beetle Eriopis connexa (Coleoptera: Coccinellidae) are excellent models for these studies, particularly as many dsRNAs are designed to target coleopteran pests. Therefore, it is crucial to assess the biosafety of this technology for beneficial species. This study aimed to verify the functionality of dietary RNAi in E. connexa and to evaluate the adverse effects of exposure to dsRNAs designed for the cotton boll weevil, Anthonomus grandis (Coleoptera: Curculionidae). Additionally, I propose E. connexa as a surrogate model for non-target effect studies adapted to tropical conditions. The established protocols and this ecologically relevant model will support future biosafety assessments, contributing to the responsible development of sustainable pest control strategies.

The Madagascar hissing cockroach, Gromphadorhina portentosa, has attracted increasing scientific and productive interest due to its potential as a model organism in biological studies and as an alternative nutrient source—particularly protein—for animal feed. The search for more sustainable food systems has driven the use of insects, which exhibit high feed conversion efficiency and lower environmental impact compared to conventional livestock production. In this context, the present study aimed to evaluate the influence of different agro-industrial diets on the biological, metabolic, and digestive histological performance of G. portentosa nymphs. Nymphs were fed a control diet based on wheat bran and experimental diets formulated with cottonseed meal, soybean meal, barley, DDG (Distiller’s Dried Grains), and DDGS (Distiller’s Dried Grains with Solubles). Initially, the diets were subjected to bromatological characterization. Subsequently, biological parameters—including survival, biomass gain, and morphometric development (body mass, insect size, and pronotum dimensions)—were assessed as indicators of growth and ontogenetic progression in newly hatched nymphs (0–24 h), monitored weekly over an 18-week experimental period. In parallel, biochemical analyses were conducted to determine body contents of total soluble proteins, lipids, glycogen, and total sugars, in addition to histological analyses of the midgut. The results showed that survival did not differ significantly among diets, whereas biological and metabolic performance was influenced by the nutritional composition of the substrates. Diets based on DDG and DDGS exhibited higher nutritional density, resulting in greater biomass gain, improved body development, and higher levels of energy reserves. Histological analyses indicated preservation of midgut epithelial organization in most treatments, while the cottonseed-based diet promoted structural alterations in the midgut and the barley-based diet induced intestinal epithelial metaplasia. Overall, DDG and DDGS stood out as the most efficient diets, highlighting the potential of G. portentosa nymphs for sustainable insect production systems aimed at animal feeding.

The ring-legged earwig, Euborellia annulipes (Lucas) (Dermaptera: Anisolabididae), is an omnivorous predator found in various agroecosystems, including brassica crops, with great potential for use in integrated pest management. Therefore, the study conducted in this thesis aimed to elucidate the impact of this natural enemy's herbivory on its biology, as well as its field efficiency as a biological control agent. Although the species exhibits omnivorous habits, supplementing the diet with plant material from different brassica species (Pak choi cabbage, Portuguese cabbage, cabbage, and radish) did not result in biological improvement. However, second-instar nymphs were able to complete their development by feeding exclusively on Pak choi cabbage (66%) and Portuguese cabbage (43.3%). Earwig herbivory was more pronounced in the absence of food; nonetheless, even with weekly releases in the absence of prey, the earwig was not capable of compromising the yield of Pak choi cabbage. Regarding practical application, the release of E. annulipes proved to be a viable alternative, where the release of four earwigs per two plants promoted effective pest control. Furthermore, the integration between chemical and biological control allowed for a reduction in insecticide applications while maintaining pest suppression. Thus, it is concluded that the predatory earwig E. annulipes is a robust natural enemy, capable of surviving periods of prey scarcity through herbivory without causing economic damage to the crop. Its incorporation into brassica production systems offers a sustainable strategy to reduce reliance on synthetic pesticides.

Aedes aegypti (Linnaeus) represents a major public health threat, as it is the primary vector of arboviruses. Its control relies mainly on the use of synthetic pesticides, which cause environmental damage, are costly, and favor the development of resistance. Therefore, the investigation of natural insecticides derived from plant compounds is necessary for the development of effective products. Although terpenes and phenylpropanoids are abundant constituents of essential oils, their effects on the digestive and immune systems of insects remain poorly understood. Thus, this study aimed to evaluate trans-anethole (a phenylpropanoid) and linalool (a terpene) as larvicidal agents, applied individually and as a binary mixture. In larvicidal bioassays, the median lethal concentrations (LC₅₀) were determined for trans-anethole (68.41 ppm), linalool (240.57 ppm), and the binary mixture (96.43 ppm). To assess immune responses, fourth-instar (L4) larvae exposed to the LC₅₀ values were analyzed for oxidative stress, phenoloxidase activity, melanization, nitric oxide levels, reduced glutathione (GSH), and macromolecule content (proteins, lipids, sugars, and glycogen). Histological, histochemical, apoptosis, and PCNA analyses of the larval midgut were also performed. Trans-anethole and the binary mixture exhibited high toxicity, with particular emphasis on the mixture, which intensified melanization and other immune responses in the larvae and negatively affected their nutritional reserves and cellular homeostasis, suggesting that prolonged exposure may compromise Ae. aegypti survival. All treatments induced oxidative stress, with linalool showing a low antioxidant response mediated by GSH. Only linalool and the binary mixture altered protein and carbohydrate levels in the midgut. All treatments caused morphological pathologies in epithelial cells and induced apoptosis, without evidence of cellular regeneration, indicating that this organ is a major target of acute toxicity. Finally, the compounds and their mixture can be considered promising active ingredients for the development of effective and sustainable biolarvicides.

Termite control strategies based on slow-acting, non-repellent insecticides rely on the principle of horizontal transfer within colonies. However, in practice, colonies often persist despite sustained exposure, suggesting that intrinsic biological mechanisms buffer the effects of chemical stress. This thesis investigates how social organization and caste-specific physiological processes interact to modulate tolerance to insecticides in the neotropical termite Nasutitermes corniger. Through a series of laboratory bioassays, we examined (i) how caste identity shapes behavioral interactions with intoxicated nestmates, (ii) whether soldiers mediate group-level behavioral responses that mitigate neonicotinoid stress, and (iii) how detoxification capacity is distributed among castes via esterase activity. Our results demonstrate that contact with intoxicated individuals triggers caste-dependent behavioral adjustments, with soldiers inducing behavioral cascades that reduce exposure and increase group survival under imidacloprid exposure. In contrast, workers were identified as the primary drivers of enzymatic detoxification, exhibiting higher esterase activity irrespective of soldier presence. Together, these results indicate a division of labor in which soldiers function as behavioral regulators that buffer social stress, while workers bear the physiological burden of detoxification. By integrating behavioral ecology and enzymatic mechanisms, this thesis advances the concept of social buffering against insecticides and provides a more realistic framework for understanding termite tolerance and the limitations of colony-level control strategies.

The sting is a modification of the ovipositor, shared by all taxa of the Aculeata, which include ants, wasps and bees. Morphological studies involving descriptions of this structure are relatively frequent for certain taxa. However, the sting is still little explored in comparative studies, even with useful characters in taxonomic delimitations. To investigate the informative potential of this structure, we used bees from the Anthidiini tribe as a model. The objective of this work was to investigate the morphology of the sting of thistaxa, carrying out a comparative  morphological study to understand the evolution of this structure within the tribe and indicate new characters that help in generic delimitation. For this, females from 26 genera and 55 species of Anthidiini were analyzed, as well as females from other three tribes of Megachilinae. The morphological study demonstrated that there is a generic pattern for some of the sting structures. The use of these characters can help with generic delimitations in the current classifications of the tribe. Besides that, the data obtained confirm the importance of use of sting in comparative morphological studies involve the distinct lineage of Aculeata. 

The tomato leaf miner, Phthorimaea absoluta, is a devastating pest for tomato crops (Solanum lycopersicum), causing significant economic losses. The most widely used method for its management is chemical control. Due to its biological characteristics and the widespread application of chemical insecticides, cases of resistance have developed. Azadirachtin, an active compound extracted from neem seeds, has emerged as an important alternative in integrated pest management (IPM) due to its low toxicity to non-target organisms and its effectiveness in controlling P. absoluta. However, information on the susceptibility status of P. absoluta to this molecule is scarce. Therefore, this study aims to monitor the susceptibility of populations of P. absoluta from different regions of Brazil to azadirachtin through bioassays using tomato leaf immersion with the recommended label concentration and concentration-response curves between 2021 and 2023, using leaves treated in azadirachtin solutions in Petri dishes with mortality assessment at 96 hours. The results revealed significant variation in the susceptibility of P. absoluta populations to azadirachtin. The populations from Irecê- BA and João Dourado-BA showed CL50 values of 125.86 mg a.i./L (2023) and 121.3 mg a.i./L (2021), 16.95 mg a.i./L (2023) and 13.75 mg a.i./L (2021), respectively. The resistance ratio varied 7.6 times for the 2021 crop and 3.8 times for the 2023 crop. The lethal concentration for 80% of the population (CL80) varied, with higher values observed in populations from Araguari-MG (271.94 mg a.i./L) and Irecê-BA (246.53 mg a.i./L) in the 2021 crop, and Petrolina-PE (246.53 mg a.i./L) and Irecê-BA (340.40 mg a.i./L) in the 2023 crop. The populations from Irecê-BA and Petrolina-PE showed the highest probabilities of control failure, indicating the need for more robust management strategies in these regions. P. absoluta was shown to be susceptible to azadirachtin, making this molecule a promising tool in the management of P. absoluta. This study reinforces the importance of including this insecticide in IPM programs to reduce selection pressure for resistance and promote more sustainable agricultural practices. Therefore, these findings contribute to the management of this pest insect. 

Coccinellids are widely used as biological control agents in integrated pest management. Most coccinellid species are either aphidophagous (feeding mainly on aphids) or coccidophagous (feeding primarily on scale insects), relying on a consistent supply of natural prey. However, these preys are not always readily available in the field or for laboratory rearing. Diets lacking natural prey typically impair reproductive performance, resulting in prolonged pre-oviposition periods, reduced fecundity, and lower egg viability. A key hypothesis is that vitellogenin (Vg), a critical yolk protein, is strongly influenced by dietary changes and regulated by hormonal pathways and insulin-like peptides that modulate its synthesis based on environmental conditions. This study investigated the biological and molecular effects of the absence of preferential prey on the reproduction of the neotropical ladybird Eriopis connexa (Germar). Females were fed either a combination of Ephestia kuehniella Zeller eggs and aphids [Lipaphis pseudobrassicae (Davis)] or E. kuehniella eggs exclusively. Reproductive parameters, including pre-oviposition period, egg size, fecundity, egg viability, female weight, and longevity, were evaluated. Additionally, protein, lipid, glycogen, and total sugar levels were quantified, and the expression of key genes involved in Vg and glycogen synthesis was analyzed using RT-qPCR. These findings provide valuable insights into how dietary deficiencies affect reproductive performance and could contribute to improving the mass rearing of coccinellids for integrated pest management programs.

Brazil is the world's leading producer of sugarcane. However, pests such as the sugarcane
borer (Diatraea saccharalis), the primary sugarcane pest in the Americas, can cause
significant losses in crop production. To minimize the damage caused by this pest,
chemical, biological, and biotechnological control strategies have been employed. The
established use of parasitoids such as Cotesia flavipes, along with the recent adoption of
Bacillus thuringiensis (Bt) Cry toxins in genetically modified sugarcane (Bt sugarcane), has
gained prominence. However, in the case of Bt sugarcane, continuous use may select for
resistant populations, compromising pest control and highlighting the need for in-depth
studies on resistance mechanisms, often relying on genomic sequencing and transcriptomic
analyses. Accurate taxonomic identification of the species used for sequencing is essential
for reliable genomic and transcriptomic analyses, as the resulting data will serve as the
basis for subsequent studies. Traditionally, taxonomic identification relies on morphological
characteristics, which may require specialists who are not always readily available. In this
study, we analyzed Diatraea saccharalis sequences available in GenBank, including both
individual sequences and those from annotated genomes and transcriptomes, to assess
potential species misidentification. An initial phylogenetic analysis was performed using D.
saccharalis homologous sequences found in other species within the Crambidae family,
such as Diatraea impersonatella, Chilo suppressalis, Ostrinia nubilalis, and Ostrinia
furnacalis. Subsequently, a more detailed phylogenomic analysis was conducted using the
BUSCO tool, based on conserved single-copy genes across the genomes and
transcriptomes of these species. Species misidentification in major databases can severely
compromise research outcomes across multiple disciplines and may lead to misguided
strategies, particularly in critical areas like pest control and management.

The commercialization of natural enemies is an important tool used in biological pest control. Predatory mite species are registered with the Ministry of Agriculture and Livestock (MAPA) and marketed for the management of the pest mite Tetranychus urticae. A commercial predator specializing in preying on mites of the Tetranychidae family is Neoseiulus idaeus, which is widely distributed in arid environments. As for chemical control, the use of selective products of botanical origin, such as essential oils and isolated plant compounds, is considered an alternative for the management of T. urticae. Thus, this study aimed to evaluate the possible selectivity of EO extracted from Melaleuca leucadendra leaves and its major constituent on N. idaeus. To this end, bioassays were conducted to evaluate the mortality of N. idaeus when subjected to a concentration indicated for field use (LC80) of EO and its main compound, estimated for the control of T. urticae. Effects on parameters such as functional response and fertility of F1 of the predator species when exposed to sublethal concentrations (LC30) of the oil and compound mentioned above were also evaluated, in addition to the positive control Azamax®. Through chemical analysis and identification of the EO of M. leucadendra, sesquiterpene (E)-Nerolidol was observed to be the major component, corresponding to 95.48%. Residual contact tests of M. leucadendra and (E)-Nerolidol on T. urticae showed average lethal concentrations (LC50) of 6.28µl/mL and 6.91µl/mL, respectively, with no statistical difference. Azamax®, on the other hand, had an LC50 of 2.49 µl/mL, being more toxic to T. urticae than EO and the compound. In toxicity tests on N. idaeus with LC80, it was observed that while EO and Azamax® presented mortality rates considered non-toxic, the isolated compound was slightly toxic to the predatory mite. Functional response experiments indicated that EO and the compound did not compromise the predatory capacity of N. idaeus, promoting a type II functional response, similar to the control result, with only an increase in prey handling time. Azamax®, on the other hand, was able to alter the functional response of the predatory mite to type I. Regarding the F1 fertility experiment, OE and the compound caused a reduction in the oviposition of N. idaeus in F0, while in F1, the compound and Azamax® caused this decrease. Therefore, the results obtained through this study have the potential to contribute to the sustainable management of the striped mite, providing support for integrated pest management (IPM) programs.

During resource acquisition in the environment, termites must face dynamic risks and be strategic in their decisions. Despite being known for their incredible cohesion, a consequence of their chemical communication, little is known about how these insects respond to risk signals during resource selection. In addition, we understand a little about the role of soldiers in mediating these decisions. In this thesis, we sought to analyze whether groups of Nasutitermes corniger perceived and responded to chemical risk signals during food selection. To this end, we conducted behavioral experiments, offering food resources with variations in the chemical risk ranges and in the caste composition of the group. We initially tested whether isolated chemical signals from predators and competitors influenced collective foraging decisions. We then analyzed the presence and proportion of soldiers influencing collective decisions, through their sensitivity to risk and the ability to redirect the group in the face of chemical predation cues. The results indicate that N. corniger termites can differentiate the risk associated with the resource, adjusting their foraging behavior according to the origin of the risk. Furthermore, the presence of soldiers and a greater proportion of soldiers involved than the group risked exploiting threatened resources, showing that soldiers brought increased opportunities for resource exploitation. The results of this study are important for a better understanding of how termites use chemical cues to mitigate the costs involved during resource selection, as well as highlighting the importance of the defense caste in this decision-making.

Phytoseiidae mites are known for their predatory behavior, and many species within this family are used as biological control agents. Therefore, most biodiversity sampling efforts for these mites have been carried out in crops systems. As a result, little is still known about the biodiversity of phytoseiid mites in preserved natural environments. In Brazil, recent efforts have been made to study the acarofauna of phytoseiids in natural environments. However, collection sites are primarily located in the central and southern regions of the country. Most surveys of phytoseiids conducted in the state of Pernambuco have focused on collection sites in cultivated areas, coastal margins, and areas near roads. the objective of this study is to survey mites of the Phytoseiidae family associated with plants in a remaining fragment of atlantic forest in the state of Pernambuco, Brazil. The survey revealed 17 species of phytoseiid mites, one of which is a new species and nine reported for the first time in the state. Phytoseius bennetti De Leon is reported for the first time in brazil, with the description of the male of this species. Additionally, a complementary description of Metaseiulus (Metaseiulus) adjacentis (De Leon) is provided in this study.

Knowledge of the action of botanical compounds is a necessity faced in the control of Aedes aegypti. However, most studies focus on toxicological parameters, with their interaction with the intracellular environment being little explored. Studying the compounds terpinolene and 1-butyl-3,4-methylenedioxybenzene (BMDB), Silva et al. (2016) found its promising insecticidal action on this vector. Given this, the hypothesis was raised that the toxicity of these compounds is related to damage to the intestinal epithelium, impacting its defense mechanisms, and that such damage is more significant and permanent compared to its binary combination, due to its action on multiple target sites. To validate them, their effects were evaluated at cytotoxic (immunohistochemistry - Apoptosis and Cell Proliferation) and immunological (phenoloxicity, nitric oxide and oxidative stress - TBARS and Glutathione Transferase) levels. The LC₅₀ of the isolated compounds were used according to Silva et al. (2016). For the association curve, the LC₅₀ was less toxic than the isolated compounds. The midgut showed histological changes in all treatments when compared to the control, however more severe sequelae such as vacuolization, cell swelling and loss of the peritrophic matrix were expressed in the association. As for apoptosis, only treatments containing BMDB, isolated and associated, showed an increase when compared to the control. In PCNA, larvae from the association showed a lower rate when compared to other treatments. For phenoloxidase and nitric oxide, a reduction in BMDB and the association was found, in relation to the control. In oxidative stress there was no statistical difference in the measurement of glutathione, whereas the TBARS showed a reduction in association. Therefore, it is noteworthy that, among the compounds studied, the binary combination resulting from the association presented the best results resulting from more severe damage. It is worth noting that these results were obtained at CL₅₀, and that higher concentrations, similar to those used in the field, or in different proportions can provide even more expressive and effective effects for the management of this vector.

Beta-glucosidases (β-glucosidases or BGs) are enzymes that act on carbohydrates and are important in insect-plant interaction and insect xenobiotic metabolism. These enzymes mostly belong to the glycosyl hydrolase family 1 (GH1). They are essential for digestion in lepidopterans, especially when associated with the consumption of cellulosic biomass. Thus, in this study, we aimed to identify and characterize genes encoding enzymes with GH1 domains from the intestinal transcriptomes of Diatraea saccharalis (Fabr., 1794) (Lepidoptera: Crambidae), Diatraea impersonatella (Walker, 1863), and Telchin licus licus (Drury, 1770) (Lep.: Castniidae), using bioinformatics analysis with local and NCBI databases. Of the three species studied, only D. saccharalis has a sequenced and annotated genome deposited in the NCBI. GH1-containing genes were identified in all three species. Based on these data, an initial microsynteny analysis was performed on the gene loci identified in the D. saccharalis genome compared to those of Chilo suppressalis (Lep.: Crambidae) and the model insect Bombyx mori (Lep.: Bombycidae) to verify the conservation of the chromosomal position and context of each GH1 gene found. Subsequently, a phylogenetic analysis was conducted with GH1 sequences from different insect orders, with an emphasis on the order Lepidoptera. Finally, focusing on the species D. saccharalis, we identified GH1 genes that were downregulated when larvae fed on sugarcane, their natural diet. These results were confirmed by RT-qPCR. Finally, we evaluated the effect of the antinutritional compound amygdalin on the expression of GH1 genes to correlate with the results from feeding on sugarcane. Therefore, by identifying and characterizing genes of enzymes expressed in the midgut, which may be involved in cellulose degradation in Lepidoptera, we identified targets with potential biotechnological applications, whether in biofuel production or in the development of tools for controlling sugarcane lepidopteran pests.

Chemical control is the preferred method used for the key tomato pest Neoleucinodes elegantalis, however its efficiency has not been satisfactory and its indiscriminate use has caused an increase in production costs. Essential oils appear as a promising alternative and their association with biological control, such as the use of the parasitoid Trichogramma pretiosum, can enhance its results, being an option to be considered. Thus, this research aimed to analyze the effects of Origanum majorana and Copaifera officinalis oils on the physiology of N. elegantalis through the histology and histochemistry of the gonads, comparing with commercial formulated products (azadirachtin and deltamethrin) and the effect of the association of essential oils of Amyris balsamifera and Pelargonium graveolens with T. pretiosum, through biology and functional response and its toxicity to the pest, in comparison with the formulated products azadirachtin and deltamethrin, in addition to chromatography of the aforementioned oils. All tested oils were mostly made up of terpenes. O. majorana oil presented greater toxicity compared to C. officinalis and demonstrated better performance by altering important parameters in the physiology and histochemistry of the gonads of this pest, causing a reduction in yolk and total proteins in the ovarioles; and in the testicles, reduction of sperm, carbohydrates and proteins. For the combination of methods, P. graveolens oil with T. pretiosum was the one that showed the best results, with greater toxicity to the pest. For the parasitoid, this oil appeared, in terms of selectivity, to be slightly harmful, not compromising its performance, in addition to promoting a type II functional response. Therefore, the use of oils and their association with T. pretiosum to control N. elegantalis becomes an interesting tool in IPM programs, as long as the particularities that guide this interaction are observed.

Phytoseiidae is a predatory mite family used to control insect and mite pests worldwide. Knowledge about the species that make up this group has advanced in recent decades, but it is still limited for some Brazilian biomes, such as the caatinga. Promising species for the control of local pests may be being lost due to the lack of work carried out in these areas, which are home to a rich endemic biological diversity, adapted to climatic conditions of high temperature and low humidity. Because they are mites that mainly inhabit plants, these can act as reservoirs for the maintenance of biological control agents in natural environments and in agroecosystems. Therefore, the present work aimed to carry out a survey of phytoseiids in areas of Caatinga in the state of Pernambuco, Brazil, as well as to describe new species found. Sampling was carried out in three areas in the municipalities of Bonito, Caruaru and São Caetano, with a total of 1044 adult specimens (females and males) collected, belonging to 37 species of 17 genera. Six morphospecies have only been identified to genus level and possibly represent species that have not yet been described. Amblyseiinae was the subfamily with the highest number of species (24), followed by Typhlodrominae (5) and Phytoseiinae (2). The species Amblyseius operculatus De Leon, Euseius mesembrinus (Dean), Iphiseiodes zuluagai Denmark & Muma, Phytoseius woodburyi De Leon and iv Galendromus (Mugidromus) agreste Silva, Gondim Jr. & Demite were the most abundant. The number of species collected demonstrates that the Caatinga has a great diversity of phytoseiid mites and requires more comprehensive studies, since few areas were sampled to date.

Insects do not possess an adaptive immune system like vertebrates. They primarily rely on the innate immune system, composed of humoral and cellular responses, to defend against parasites and pathogens. The humoral response consists of various signaling pathways that result in the production of molecules such as antimicrobial peptides (AMPs) and melanin, which act against the invading agent. Despite numerous studies describing the types of responses and signaling pathways of the insect immune system to different pathogens, most are conducted with model insects or with non-natural pathogens. This study investigated different aspects of the immune system of Diatraea saccharalis (Lepidoptera: Crambidae), the major pest of sugarcane in Brazil. In the first study, the main genes involved in the signaling pathways of the humoral response were characterized: Toll, IMD, Jak-STAT, and the Profenoloxidase (melanization) pathway. After characterization, the modulation of at least one representative gene from each pathway was investigated in insects treated with different biological control agents, such as the bacterium Bacillus thuringiensis (Bt), the fungus Metarhizium anisopliae, and the parasitoid Tetrastichus howardi. In the second study, the focus was on the characterization of AMPs in D. saccharalis, highlighting a lebocin, a proline-rich peptide, which shows increased expression in the heads of larvae fed on sugarcane or when ingesting Bt spores and crystals. In the final study, it was examined whether T. howardi would induce immunological priming in D. saccharalis adults, with positive effects on the pest's offspring. Immunological priming occurs when a past exposure or infection leads to a more effective immune response upon a secondary exposure. However, the offspring of D. saccharalis were more susceptible to the parasitoid due to compromised immunity caused by prior exposure. From these results, new aspects of the immune system of D. saccharalis were unveiled, which can contribute to the improvement of the use of biological control agents as well as the development of new sustainable pest control technologies.

Viruses identified in mosquitoes are subdivided into two groups: arboviruses, transmitted to vertebrates and able to replicate in both vectors and hosts, and insect-specific viruses (ISVs), which have replication capacity restricted to the invertebrate host. ISVs have the capacity to modulate responses and effects against arboviruses when co-infected in mosquitoes, therefore, the prospection of these ISVs becomes important for analyzes of possible interferences in arbovirology studies. In the last decade, the use of metagenomics tools in the surveillance of medically important arboviruses has been shown to be efficient in the discovery of new ISVs, due to the sensitivity and high throughput of the techniques employed in next-generation sequencing (NGS). Therefore, the objective of this work was to establish a functional protocol for the detection of ISVs in mosquitoes and (C6/36) cells from laboratory strains, and perform the identification of ISVs in the respective groups by NGS. Two methods for virus detection were tested: conventional PCR using degenerate primers for flaviviruses and alphaviruses, using Cx. quinquefasciatus and Ae. aegypti sample and next-generation sequencing, in samples of laboratory mosquitoes and C6/36 cells. It was not possible to detect ISVs using the conventional PCR technique. Metavirome analysis by NGS reveals three viruses: Culex bunyavirus and Wutai mosquito phasivirus in samples of Cx. quinquefasciatus. Culex densovirus was detected in three of four supernatant samples from C6/36 cells co-infected with dengue serotypes 1, 2 and 3. Culex densovirus had 100% coverage of the genome with a depth of 21.872 x. The results bring an efficient metavirome protocol in the detection of ISVs and arboviruses, in addition, this work reinforces the need for metavirome analysis in arbovirology studies.

Given the great importance of Apis mellifera bees as ecological agents, highly associated with humanity, it is essential to identify the causes of their decline. Thus, this work aimed to evaluate the immune system of these pollinators in a comparative way between synthetic and natural pesticides, since the use of these chemical pesticides is pointed out as one of the multifactors that cause the reduction in the population of bees. For this, workers were contaminated via ingestion, for 24 hours, with the CL₅₀ of the insecticide Karate^®, the compound Limonene, and the herbicide Roundup^®. For the Azamax^®, a concentration of 250 mL/100 mL was used, since higher doses were repellent to bees. Then, the workers were used for analysis of apoptosis, cell proliferation, oxidative stress, phenoloxidase enzyme activity and nitric oxide levels. As a result, it was found that all products studied caused midgut cell necrosis, with no evidence of regeneration through cell proliferation. Furthermore, with the exception of Limonene, all xenobiotics underwent oxidative stress, which may explain the observed necrotic process. Although nitric oxide (NO₂) is an important signaling molecule for the recognition of xenobiotics, its excessive production can generate oxidative stress. There was also an increase in phenoloxidase activity in all samples, this enzyme is also involved in the mechanisms of recognition of foreign agents and in the production of melanin. Taken together, the data show the high risk that these bees run with the possibility of coming into contact with these pesticides during their life cycle, whether synthetic or natural. Thus, it is evident that there is a need to test products in isolation.

Dicranthidium is a genus of solitary bees with eight described species. The species are distributed exclusively in the Neotropical region with records for Argentina, Brazil, Paraguay and  Trinidad and Tobago. Although widely distributed, information about the nesting biology of the genus is restricted to two species: Dicranthidium arenarium (Ducke) and Dicranthidium luciae Urban. However, these information are related only to the material used in the construction of brood cells and immature development time. Dicranthidium arenarium is  widely distributed in the Northeast of Brazil , with records for dry forest (Caatinga) and Atlantic Forest. Therefore, this study aimed to expand the knowledge about the biology of the species D. arenarium to understand patterns of seasonality, behavior, nest architecture and parasitism in two biomes of occurrence.  Dicranthidium arenarium presented similar seasonality and nest architecture in both  biomes, a multivoltine life cycle and the use only resin in nest construction. The information obtained increases the knowledge about the biology of the species and can contribute to the establishment of sustainable ways of preservation and conservation the species and the associatedbiomes.

Insect reproduction is dependent on developing oocytes synthesizing and absorbing vitellogenin, a process known as vitellogenesis. Vitellogenins (Vg) are glycolipoproteins that are primarily synthesized in fatty body cells and undergo a series of transformations before being excreted in the hemolymph and internalized in the oocytes. VgRs are oocyte membrane proteins that are responsible for the internalization of Vg, and their presence in the ovaries is required for female reproduction. Many insect Vg and VgR genes have already been identified, characterized, and functionally validated using RNA interference (RNAi). Because RNAi allows for the inference of gene function from the phenotype produced by silencing, this technique can be used to unravel the function of Vg and VgR and other genes in natural enemies such as ladybirds, paving the way for the development of methodologies that can preserve or even rear them on a large scale for field release. Interestingly, nutritional factors have a strong influence on the expression of Vg and VgR, as they regulate both the nutrition signaling pathways and the hormone synthesis pathways required for their expression. Therefore, the purpose of this study was to identify and functionally validate Vgs and VgR of Eriopis connexa (Germar) (Coleoptera: Curculionidae) by RNAi, a predatory ladybug that primarily controls aphids, as well as to investigate the effect of preferential feeding on the expression of reproductive genes in this species. As a result, two Vgs genes and one VgR gene were discovered and characterized. Vg expression rates appear to be influenced by food type. Furthermore, experimental conditions for injecting dsRNA into insect hemolymph were established. RNAi-mediated gene silencing revealed that, unlike in other species, these genes knockdown have no effect on oviposition but are critical for egg viability in E. connexa. Furthermore, the two vitellogenin genes appear to be redundant, as both must be silenced to affect egg viability.

Oryctini Mulsant, 1842, belonging to Dynastinae with 26 genera and 230 species in the world. Among these genera, seven have occurrence records for Brazil with a total of 45 species reported. The genus Enema Hope, 1837 belongs to this tribe and currently has two species, E. pan (Fabricius, 1775) with a distribution from Mexico to Argentina and E. endymion Chevrolat, 1843, present in Central America and northern South America. The taxonomy of the genus remained more than years without any updates, and it was never analyzed phylogenetically. The objective of this work was to verify the synonyms through the primary types available in addition to analyzing the genus phylogenetically. For this, material from other collections was borrowed, in which their external morphology and male and female terminalia were analyzed and photographed, species distribution maps were also provided. After the taxonomic review, a morphological difference was found within the population named E. endymion, which was considered to be only the population occurring in Central America. The synonym E. gibicollis Sternberg, 1908 was revalidated, with diagnostic characters and new distribution data provided. A new species was described, Enema josis with occurrence for northeastern Brazil. Cladistic analysis confirmed the genus as monophyletic. Thus, this study contributes to the knowledge of the phylogenetic relationships of Enema, provides an identification key, updates the limits of species distribution and can be used as a contribution to the conservation of this rare taxon.

The lady beetle Tenuisvalvae notata (Mulsant) is an insect that occurs in South America with an optimal temperature range varying from 20-28 ºC, with effects on its reproduction outside this optimal range. Previous studies have shown that T. notata can be acclimated to temperatures outside its optimal range, both low and high up to a limit, which allows insect survival. However, they do not reproduce satisfactorily or totally. Thus, this study investigated how temperature may affect predator insects reproduction, as well as the nutrition and morphology of the gametes of insects subjected to different temperatures. Results showed that lady beetle males were affected by the reduction in temperature, with a delay in sex maturation. Females reared in the laboratory at the control temperature (28 ºC) had higher fecundity in semi-field conditions, followed by those reared at 32 ºC and 18 ºC; this could be related to immature male gametes. Biochemical analyses showed differences in lipids and total sugar contents in male and females gonads, with a reduction in comparison to the control (28 ^oC). Similar results were found for males, in which testicles of males reared at 32 ^oC e 18 ^oC had more cists and empty spaces with no spermatozoa in comparison to the control. There was a reduction in the amount of carbohydrates only in ovarioles of females reared at 18 ^oC. The amount of total proteins did not differ among treatments. Further studies may focus on aspects of nutrient absorption through the midgut and how this may be related to the trade-off between survival and reproduction in T. notata.   

The release of natural enemies is one of the most used strategies in integrated pest management, being commonly used parasitoid and insect predators. Among predators, the species Cryptolaemus montrouzieri and Tenuisvalve notata stand out, both coccinellids for being predators of mealybugs (Pseudococcidae). The mass production of these predators standardizes the breeding conditions. It generates a selection pressure that can improve or negatively affect the performance of the predator in the field after several generations of brood. Therefore, we evaluated whether the ladybugs T. notata and C. montrouzieri have a feeding preference for the mealybugs on which they were reared, what the metabolic cost associated with the production of wax in the larval phase of these predators, and whether there is an effect of the chemical composition of the wax in the predator-prey interaction, using, in this case, the mealybugs Ferrisia dasylirii and Planococcus citri as a biological model. It was observed that both ladybugs responded similarly to the volatiles released by both of the offered prey.

Furthermore, there were no changes in predator behavior in relation to prey cues. Also, both predator species consumed more P. citri in laboratory and semi-field tests, regardless of the prey they were reared on, indicating no pre-imaginal conditioning of the predator. Regarding the wax production strategy, it was shown that there is a metabolic cost associated with its removal, the predators showed a significant reduction in adult body weight when the wax was removed, as well as in the fecundity and viability of the eggs. Finally, the results showed that the predator-prey interaction does not affect the wax profiles of the predator's body, as they are not similar to the chemical profiles of the wax prey.

Neoleucinodes elegantalis Guenée (Lepidoptera: Crambidae), stands out as one of the main pests of tomato production, causing direct damage by severely infesting the fruits. Its control is done by chemical insecticides, but due to the endophytic habit, it is necessary to apply recurrent broad-spectrum insecticides. Thus, essential oils associate with biological control emerge as biorational alternatives to minimize the effects of continuous and improper use of these products. Despite the growing interest in these control methods and the already proven promising results, there are few studies that elucidate the possible effects of oils on the performance of natural enemies. Thus, this research aims to analyze the effects of essential oils from Origanum majorana and Copaifera officinalis, on the biology and nutrition of N. elegantalis, as well as their effects on T. pretiosum, comparing with the formulated products azadirachtin and deltamethrin. The LC50 of the referred oils were used, through the establishment of the concentration curve, and the recommended field dose for the insecticides. The following were analysed: 1. Regarding the oils: the chemical profile through GC-MS; 2. Regarding the pest: average entry and exit of holes in the fruits, biology (larval development, pre-pupa and pupa weight, pupal development), reproduction iv (oviposition and viability), nutrition (proteins, lipids, glycogen and total sugar); 3. Regarding the parasitoid: biology (parasitism, emergence, longevity, sex ratio, toxicity class and reduction of parasitism), functional and numerical response (attack rate, manipulation time and type of response). Among the tested oils and insecticides, C. officinalis showed the best performance by altering important parameters of pest biology (elongation of larval development and reduction in pre-pupa and pupa weight), presenting greater selectivity to the parasitoid, in addition to reducing the time of manipulation and increase the attack rate, being therefore promising in the control of this pest due to its effectiveness and beneficial interaction with T. pretiosum.

The diamondback moth, Plutella xylostella, is the main limiting factor for cabbage cultivation in tropical areas of the world, due to its high reproductive capacity and fast life cycle. However, the indiscriminate use of insecticides has generated several problems, therefore, due to the aforementioned problems caused by the use of insecticides, processes that are less aggressive to man and nature in general have been sought. Therefore, alternative control measures must be adopted, such as the use of botanical insecticides in the form of extracts or essential oils. Thus, this thesis aims to evaluate and analyze the insecticidal potential of sublethal doses of essential oils from species belonging to the Rutaceae and Lamiaceae families, to be used in the control of P. xylostella, as well as to identify the main interferences in the morphology, biology and insect behavior induced by these oils. The insecticidal activity was evaluated through the application of sublethal concentrations of essential oils of Citrus limon, Citrus aurantium and Mentha spicata, through bioassays of larval toxicity, fertility life table and behavioral tests.

Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) parasitizes pupae of sugarcane stalk borers. The parasitoids in current use against sugarcane stalk borers parasitize only eggs and larvae, while T. howardi will add parasitism of pupae that have a high survival rate inside the stalks. To recommend T. howardi, a large rearing scale can be obtained using pupae of Tenebrio molitor (L.) (Coleoptera: Tenebrionidae) as an alternative host. The continuous use of an alternative host may negatively affect the parasitoid's performance toward the target pest due to natal host conditioning. Furthermore, the efficacy of released T. howardi can be negatively affected by the adoption of other control tactics applied to pest control, mainly insecticide applications. Thus, the biological performance of the parasitoid reared using alternative hosts and its response to insecticides applied to sugarcane crops was assessed. Host finding and choice using pupae of the sugarcane borer, Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae), were determined during 30 generations of parasitoid rearings using pupae of T. molitor. In addition, the biological and behavioral responses of the parasitoid were evaluated after exposure to dry residues of the insecticides chlorantraniliprole, bifenthrin, spinetoram, ethiprole, fipronil, and thiamethoxam. Rearing T. howardi on pupae of T. molitor did not affect egg loading, parasitism performance, or target host choice, D. saccharalis. In cases of differences in the results, they were favorable to the parasitism of pupae of D. saccharalis. The insecticide chlorantraniliprole was compatible with T. howardi, allowing survival and host parasitism after contact with dry residues of this insecticide. Nevertheless, the other insecticides were toxic to the parasitoid. Pupae of sugarcane borer exposed to sugarcane seedlings treated with ethiprole and spinetoram were parasitized, had descendants, and the parasitoid showed the ability to evade the treated area. The findings show that T. molitor can be used as an alternative host for the continuous rearing of T. howardi for up to 30 generations without losing its performance. Females of T. howardi increased egg formation with aging, can make multiple ovipositions on unique pupa of D. saccharalis, although one oviposition is enough to kill the host and to obtain successful offspring production, and showed a significant reduction of eggs in the ovary after one oviposition and did not recover it within a 24-hour resting period.

Several factors contribute to the evolution of insect-pest resistance to a particular insecticide, since the selection pressure due to the indiscriminate use of pesticides, integrated with the type of cultivation system has guided this phenomenon and generated an increase in the frequency of resistant populations, causing failures in the effectiveness of these products in the field. Liriomyza sativae, known as the leaf miner fly, a key pest of several crops, has caused severe damage and losses to producers. The most used method for its management is chemical control. Due to its biological characteristics and the wide range of insecticides used to minimize high infestations of this diptera, reports of control failures are occurring. Insecticides of different modes of action such as cyromazine, cyantraniliprole, and spinetoram have been registered for L. sativae and are applied in an exacerbated manner.  Information about the susceptibility and the basis of resistance of L. sativae is still scarce and this information would help to better manage this pest insect. Thus, this work aims to monitor and characterize the resistance of L. sativae to the main insecticides used in the field for its control, using the methodology proposed by Santos et al. (2020). Populations from different regions of Brazil were collected for this study. The molecules used in monitoring were moderately effective in relation to the diagnostic and recommended concentrations of each insecticide, indicating resistance evolution, by allowing survival of individuals, with mortalities ranging from 3.16% to just over 90%. The populations of Arapiraca and Inhuçu showed the first cases of field resistance to spinetoram. The CL₅₀ values and resistance ratio (RR₅₀) for cyromazine, cyantraniliprole and spinetoram ranged from 5.53 - 86.61 mg i. a./L (RR₅₀ from 1.17 to 15.67 times), 0.12 - 0.91 mg i. a./L (RR₅₀ from 2.22 to 7.45 times) and 0.03 - 44.16 mg i. a./L (RR₅₀ from 3.47 to 1652.17 times), respectively. The selection with spinetoram was maintained at 180 mg i. a./L, showing a CL₅₀ of 88.25 mg i. a./L and an RR₅₀ of 4,219.80-fold. The genetic resistance of L. sativae to spinetoram was autosomal, incompletely recessive, and monofactorial. The discriminatory dose/concentration that makes spinetoram resistance recessive was 60 mg i. a./L and can be used in monitoring. Due to this magnitude of resistance, cross-resistance with spinosad and negative cross-resistance with Indoxacarb, thiamethoxan and cartap were verified. These results contribute to the management of insecticide resistance of L. sativae.

Brazil is one of the most important producers and exporters of melon (Cucumis melo L.) worldwide. Currently, Brazilian melon production is approximately 600 thousand tons per year, with the state of Rio Grande do Norte responsible for 61% of this production. The melon crop, however, faces some phytosanitary problems that cause economic losses to the producer. Among these problems, we can highlight the leafminer Liriomyza sativae Blanchard (Diptera: Agromyzidae). The leafminer females lay their eggs endophytically on the melon plant leaf; the hatched larvae develop and feed on the leaf mesophyll, forming galleries in the leaves and causing a reduction in the sugar content of the produced fruits, restricting their commercialization. One of the main ways to control this pest is through the application of synthetic insecticides. However, the importer markets have prohibited the use of some insecticides and reduced the acceptable limits of insecticide residues in fruits. In this way, it is fundamental to develop new tools to control the leafminer as an alternative to the use of these synthetic insecticides. Therefore, the objective of this study was to evaluate the effect of essential oils (EOs) of botanical origin on the control of the leafminer L. sativae in melon plants. Some of the evaluated oils proved to be phytotoxic to melon plants, while others showed a potential control effect against the leafminer. However, more research is needed to understand the mechanisms of action, in addition to assessing environmental impacts and safety for non-target organisms.

The lady beetle, Eriopis connexa (Germar) (Coleoptera: Coccinellidae), is a natural enemy found in several crop ecosystems, associated mainly with aphids’ infestation. It has probably been under selection pressure of pyrethroid applications, against defoliator pest species, resulting in selection for resistance (R). The resistance trait confers the lady beetle ability to survival pyrethroids application; thereby surviving beetles will provide aphid control precluding the recurrent aphid outbreak after a pyrethroid application. After releasing of E. connexa R phenotype, its resistance trait stability may depend on factors, such as presence of selection pressure (i), mating frequency with susceptible (S) field phenotype (ii), and the impact of minor reproductive performance due to the biological cost implied by the resistance trait (iii). A series of experiments were run including mass mating between R and S adults following by exposure to selection pressure or not, reselection, and measurement of resistance level. Additionally, biology studies were carried out in the F1 and F5 generations of descendants from R×S crosses to measure their performance in comparisons to their S and R parental. The results from mass mating R×S without selection pressure showed significant reduction of R phenotype, but it still presents in the population after four generations. On the other hand, when offspring from R×S crosses received application of lambda-cyhalothrin at field rate, the survival was equal or greater than the expected 50%. First generation of offspring R×S exhibited significant gain in the fecundity and survival. However, the gain in fecundity did not sustain after reselection. Females R exhibited lower survival than S and R×S females, but with consistent egg production at initial adulthood favoring their performance by completing generation earlier than S and R×S females. The results indicate that the maintenance of the resistance in E. connexa after field releases will depend on selection pressure. In the absence of selection pressure, the proportion of R phenotype will decrease significantly but will not be lost from the population. So, they can be reselected what partially explain the common occurrence of E. connexa R to lambda-cyhalothrin in crop ecosystem with wide use of pyrethroid.

The ecological, economic and social Apis mellifera bees, as they are essential for the maintenance of the biodiversity of wild and agricultural plants, and for the production of honey and other bee products much demanded by the pharmaceutical and cosmetics industry. However, in recent years there has been a decline in bee populations, often attributed to diam. of the collection of colonies. Thus, this study evaluated whether synthetic and natural products have an influence on the decline of bees, analyzing possible histological changes in A. mellifera, consequently as in bees treated with nutritional a compound insecticide (Azamax®) compound limonene compared to synthetic insecticide lambda-cyhalothrin and glyphosate herbicide. Ingestion of the products and compounds occurred by ingestion for a period of 24 hours. The lambda-cyhalothrin insecticide and the limonene compound were highly toxic like A. mellifera, and glyphosate showed low toxicity, while Azamax® was repellent to bees at the recommended field dose. Nutritional changes. All nutrients are responsible for the reduction in nutrient absorption (protein, lipid, total sugar and nutrients) by bees, the herbicide, glycogen compound and the herbicide compound in a reduction in nutrient absorption. These results, in addition to highlighting the impact that defensive can be beneficial on pollinators, in this case on A. mellifera results, indicate that the products are equally beneficial or more harmful to beneficial products when compared to synthetic products. It is worth mentioning that repellency Activation by the insecticide botanical insecticide is an advantage because it is more difficult for bees to contact this pesticide in agricultural fields.

The mealybug Planococcus citri (Risso, 1813) has a worldwide distribution and adapts to different climates and hosts. They are considered difficult to control because of the protection offered by their waxy layer. The most used form of P. citri control is through the use of systemic insecticides, however, the use of these products can increase production costs. Bioactivity of essential oils of the Piper genus have been investigated as promising alternatives to synthetic insecticides. Therefore, this study aimed to evaluate the activity of P. aduncum and P. marginatum essential oils on P. citri, through bioassays of topical toxicity in migratory nymphs; residual toxicity in migratory, second instar nymphs and adult females; repellency; and ovicide. The commercial botanical insecticide Azamax® was used for comparison. The CL's50 values estimated through the concentration-response curve for P. aduncum oil were 2.85 µl/mL for the topical test in migratory nymphs, and 1.83 and 1.50 µl/mL for the residual test in nymphs migratory and second instar, respectively. The estimated CL's50 for P. marginatum oil were 2.36 µl/mL for the topical test on migratory nymphs, and 2.28 and 3.81 µl/mL for the residual test on migratory and second instar nymphs, respectively. The CL's 30 and 50 of the oils estimated through tests with migratory nymphs caused mortality of 23% and 35%; and 25% and 36% of females for P. aduncum and P. marginatum, respectively. In the ovicidal test, CL's 30 and 50 reduced by 13.33% in both CL's of P. aduncum oil; and 11% (CL₃₀) and 20.56% (CL₅₀) with P. marginatum oil at the hatching of P. citri nymphs. In the repellency test, it was possible to verify that the CL₁₀ of P. aduncum was more repellent than the CL₁₀ of P. marginatum.

Although termites play an important role in the functioning of ecosystems and in increasing local biodiversity, some species are known to cause negative impacts in urban, agricultural and forest environments. Controlling pest termites is often made difficult due to their cryptic habit and their complex social organization and communication among colony members. Thus, more effective control methods for this group are becoming increasingly necessary. Termites have a sophisticated communication system, which involves chemical signals, and the management of their populations could be more effective by understanding the communication mechanisms involved in the search for resources. The study of chemical ecology, particularly involving pheromones that influence insect behavior, may be a useful tool in proposing termite control methods as an alternative to the exclusive use of broad-spectrum toxic substances. In the last decades, new approaches using pheromones for insect control have emerged, however, studies on this type of control are still lacking for insect pests in urban environments. Pheromones are non-toxic substances, biodegradable and generally specific, enabling a more ecologically viable control. Thus, the general objective of the present work was to study the chemical signals involved in foraging communication, including the role of intercolonial chemical cues. Additionally, we analyzed how these chemical cues can be used as a strategy for the control of these insect pests in urban environments. Understanding the role of intercolonial chemical signals in termites, as well as their effect on the behavior of individuals, may allow advancement in the control of these insects by promoting a direct scientific exchange between theory and applicability.

The diamondback moth and aphids are key pest species of brassicas’ crops, which frequently requires insecticide applications to their control. The use of selective insecticides complemented with resistant lady beetle open the opportunity to integrate insecticides and natural enemies for brassica’s pest control. Thus, the performance of the predatory lady beetle, Eriopis connexa (Germs) (Coleopotera: Coccinellidae), was evaluated through its exposure to insecticides recommended against the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), and the turnip aphid, Lipaphis pseudobrassicae (Davis) (Hemiptera: Aphididae). Concentration-mortality curves of selected insecticides registered against diamondback moth were determined for larvae and adults of the lady beetle (#1), and the selective indices were calculated (#2). Furthermore, the performance of larvae and adults of the lady beetle exposed to a sequence of insecticides of different mode of action were studied (#3), combined with the consumption rate of the non-target pest - moth or aphid - of the applied insecticide (#4). After determining the selective insecticides, the control of aphid and diamondback moth infestation on plants in cages and in the field was evaluated combining release of the lady beetle and insecticide applications (#5). The results show that the insecticides Bacillus thuringiensis, cyantraniliprole, chlorantraniliprole, deltamethrin, chlorfenapyr, spinosad, azadirachtin, and spiromesifen are compatible with larvae and adults of E. connexa (Exps. #1 and #2). The exposure of the lady beetle larvae and adults to a sequence of insecticides did affect its performance allowing compatible applications (Exp.#3). The diamondback larvae and aphid consumption by lady beetle adults under simultaneous exposure to the insecticides was not significantly affected (Exp. #4). The field results did not portray an additive control of diamondback moth and aphids with the release of E. connexa to the applied insecticides (Exp. #5). The number of lady beetle to be released and the release timing depending on the level of aphid infestation need to be determined for a better application of both, lady beetle release and insecticide application methods.

The acquisition of food resources is one of the most important behaviors in the life history of organisms. Despite being a basic and seemingly trivial need, resource selection is not that simple since animals live in heterogeneous environments with unevenly distributed resources, varying in quantity and quality over time. Furthermore, the presence of competing and predatory species can significantly impact the resource use. Therefore, individuals need to efficiently assess the costs and benefits involved in exploring and selecting a resource. To make decisions during resource selection, animals need to acquire information from their environment. This information can be obtained through direct interactions with the environment (i.e., private information) or even by observing other individuals (of the same or different species) and/or its cues left in the environment (i.e., social information). Termites (Blattodea: Isoptera) are detritivores insects that have great economic and ecological importance. However, the factors involved in the selection of resources for these insects are not completely known. So, the objective of dissertation was to analyze the role of social information and the combination of resource quantity and risk signals during resource selection in Nasutitermes corniger (Motschulsky) (Termitidae: Nasutitermitinae). Our results indicate that resource quantity seems to be the determining factor in resource selection in N. corniger. The role of social information and risk signals appears to depend, in part, on the quantity of resource during resource selection. This study contributes with new knowledge about the selection of resources in termites and can help to understand the habitat use by this important group of insects.

Member of the Meliponini tribe, Melipona scutellaris is originally restricted to the northeastern region of Brazil, but nowadays it is possible to find this species being raised in the southeast and south of the country, mainly due to its productivity, quality of honey and the translocation made by breeders. It is one of the most commonly raised bees in the northeast region by small families that market honey, saburá (pollen) and geopropolis, and is an important pollinator for native forest and several commercial crops. Studies directed to the composition of the microbiota of Meliponini, are rare and still do not allow us to generalize patterns of its importance and influence on these pollinators. Bacteria and fungi have proven to play important roles in their digestive system. These microorganisms act in the nutrition process, help in the immune system by fighting pathogens, among other functions that benefit the bees. The bacterial and fungal communities are also affected by stresses from diseases and insecticide poisoning, indicating disturbances in the colony. Therefore, the characterization of bacteria and fungi present in the gut of M. scutellaris opens a range of information about the health, nutrition, and adaptation of these bees, and can be used as a model for other species of the tribe. One of the best performing tools currently for microbial community characterization is the metabarcode tool. Through the sequencing of 16S and ITS gene regions it is possible to identify bacteria and fungi respectively in large scale and to know the identity of microorganisms present in the gut of bees. In this work we aimed to describe the microbiota of this important species and discuss the impacts on colonial health and maintenance. The digestive system of M. scutellarias was dominated mainly by the bacterial genera Lactobacillilus, Bifidobacterium, Floricoccus, Bombella, Pectinatus, Fruticobacillus and Snodgrassella and fungal Starmerella, Candida, Zygosaccharomyces, Malassezia, Lachancea, Aspergillus, Sterigmatomyces and Meyerozyma.

In the current study was investigated the stability of the resistance to lambda-cyhalothrin in the lady beetle Eriopis connexa (Germar) (Coleoptera: Coccinellidae). One resistant population (R-SEL) was maintained under selection pressure, while one subpopulation from R-SEL was reared without selection pressure (R-NSEL) during eight generations and compared with R-SEL and the population reference for susceptibility (SUS). The resistance ratio (RR) declined 2.10-fold for R-NSEL at 4th-generation after relieving the selection pressure, but maintained stable after when determined at 8th-generation compared to R-SEL. Likewise, alpha and β sterases activity measured at 8th-generation also declined in R-NSEL. The decreased in the resistance of R-NSEL observed at 8th-generation after relieving selection pressure was not enough to return to the susceptibility status (39-fold RR compared to SUS). The decline in the resistance level and activity of detoxifying enzymes did not reimburse the fecundity, which still being 50% lower for females R-NSEL compared to females SUS. Yet, in the current study was characterized the susceptibility of a recently field-collected population of E. connexa (SUS-C), what allowed to investigating the performance of SUS-CR-SEL progenies. The RR was 200-fold between R-SEL and SUS-C. Furthermore, developmental time from larva to adult for SUS-C was 6 days delayed and adults were smaller compared to R-SEL and to the progenies from SUS-CR-SEL. The egg production did not differ across parental populations and progenies, although numerically females from SUS-C and progenies from SUS-CR-SEL produced more than 130 eggs, tallied during 35 days, than females R-SEL. Survival of adults from R-SEL and progenies from SUS-CR-SEL, exposed to dried residues of lambda-cyhalothrin, varied from 77.4 to 100%, while adults from SUS and SUS-C exhibited null survival. Our data suggest that R-NEL exhibited stable resistance to lambda-cyhalothirn after eight generations without selection pressure. Furthermore, progenies from SUS-CR-SEL gain benefits regarding development and reproductive output, and still owning resistance level enough to survive insecticide exposure similarly to their parental R-SEL.

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) is a cosmopolitan pest, which despite having a preference for plants of the family Poaceae, also causes harms in several other cultures. Population control using synthetic insecticides is still the most used method, however, more and more studies with natural products have been made. Considering that fact, this research had the following aims: 1. To evaluate the chemical composition of the cladodes extract of Opuntia ficus-indica; 2. To evaluate the effect of cladodes extract and sodium chloride (NaCl) on biological and reproductive parameters of S. frugiperda; 3. To determine whether cladodes lectin (OfiL) is the active ingredient of the extract; 4. To investigate the effect of cladodes extract and OfiL on the activity of enzymes present in the intestine of S. frugiperda larvae. In addition, the effect of cladode extract on the histology and histochemistry of the midgut of caterpillars was also evaluated. Based on the results, it was possible to observe that NaCl when acting alone or added to the cladodes extract altered significantly the development of S. frugiperda, sometimes affecting its reproductive parameters. The cladodes extract showed to be a promising food phagostimulatory agent over the exposure time of 48 h. The cladodes extract also interfered in the histology of the epithelial tissue, in the neutral polysaccharide and proteins of midgut of S. frugiperda. When the experiments were conducted with OfiL, it was not possible to indicate its participation as an active principle in the insecticidal activity of the extract. This work contributes, therefore, to the panel of natural insecticides compounds for presenting a new bio-product with toxic effect on an important agricultural pest. Future experiments are needed to show the effect of the extract under field conditions and indicate its active(s) principle(s).

Cucumber crop has its production affected by the attack of the aphid Aphis gossypii, which colonizes the plant throughout its phenological stage. The use of chemical insecticides to control it has generated serious problems such as the emergence of resistant populations to the active ingredients used. This work aimed to evaluate fungus preparations based on entomopathogenic to control this insect pest in cucumber plants, and develop an insecticide the base of Beauveria bassiana. Under laboratory conditions, the three most promising isolates were tested, CG 864, PL 63 and IBCB 66, with five concentrations of conidia (1x105, 1x106, 1x107, 1x108 and 1x109 conidia / ml) and control (sterile water + Tween 80) . In the third stage of the experiments studies were conducted involving two preparations of biological insecticide: a) an aqueous suspension [pure conidia of B. bassiana 864 CG + 0.01% Tween 80; used as a standard] b) formulation of oil dispersion [conidia pure vegetable oil emulsifiable +] CG 864 isolated, and diluted with water for spraying the concentrations of 0.5; 1; 2 and 4% oil. The fungus preparations were standardized to have 1.0 x 107 spores / mL in applied spray. Isolates of the fungus B. bassiana were more virulent aphid A. gossypii that isolates M. anisopliae and L. longisporum. The isolates CG 864, IBCB 66 and PL 63 of the B. bassiana were the most virulent. B. bassiana preparations reduced the aphid population A. gossypii, with control efficiencies of 52.3% to 83.8%, however, there was no difference in the pest population density between the oil dispersion and the aqueous suspension conidia.

The abusive and frequent use of insecticides and a visible failure in Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) control in tomatoes, melon, and watermelon production areas have raised questions about the occurrence of leafminer resistance to insecticides used in these crops. Previous studies have shown that the genus Liriomyza flies have extensive ability to acquire resistance to several insecticides with different active ingredients. Knowledge of the current status of this pest susceptibility to registered insecticides and establishing a baseline for insecticides in the registration phase is essential to slow the development of resistance. The present study aimed to verify the existence of resistance to insecticides in order to explain these control failures. Thus, populations of L. sativae were collected in the agreste region of Pernambuco and west of Rio Grande do Norte. The populations were exposed to abamectin, spinosad, spinetoram, clorantraniliprole and ciantraniliprole. To achieve the concentration-mortality bioassays were used the immersion methodology. Populations had generally low ratios of tolerance to insecticides tested, with exception of Pau branco 1 and Mossoró 2 populations that showed moderate tolerance to clorantraniliprole and spinosad, respectively. For abamectin, cyantraniliprole and spinetoram the biggest tolerance reasons found were 1.8 for population Mossoró 2, 7.2 for population Camocim and 3.1 fold for population Mossoró 2, respectively, reflecting natural variation among the populations. Variations of enzyme activity means found probably reflect a natural response and cannot be attributed to a direct relationship with the tolerance.