Banca de DEFESA: NATALIA CAROLINA BERMUDEZ BUITRAGO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NATALIA CAROLINA BERMUDEZ BUITRAGO
DATE: 20/07/2023
TIME: 14:00
LOCAL: Auditório Fitossanidade
TITLE:

BIOLOGICAL AND BEHAVIORAL RESPONSES OF THE PARASITOID Tetrastichus howardi OLIFF (HYMENOPTERA: EULOPHIDAE) TO INSECTICIDES USED AGAINST SUGARCANE PESTS

KEY WORDS:

Insecticide selectivity, non-target effect, augmentative biological control, sugarcane stalk borer 

PAGES: 105
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Entomologia Agrícola
SUMMARY:

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.

COMMITTEE MEMBERS:
Presidente - JORGE BRAZ TORRES
Externo à Instituição - FABRICIO FAGUNDES PEREIRA - FUFGD
Externa à Instituição - ALESSANDRA CRISTINA GUEDES DA SILVA
Externa à Instituição - NATALY DE LA PAVA SUAREZ
Externo à Instituição - ROGÉRIO LIRA