Residual effect of synthetic insecticides on Trichogramma pretiosum Riley em diferentes geracoes

• Published in: Acta scientiarum. Agronomy 2008-04, Vol.30 (2), p.177
• Main Authors: Moscardini, Valeria Fonseca, de Moura, Alexandre Pinho, Carvalho, Geraldo Andrade, Lasmar, Olinto
• Format: Article
• Language: Portuguese
• ISSN: 1679-9275

This work aimed to evaluate the residual effects of the pesticides etofenprox, fenitrothion, methidathion and trichlorfon on adults of Trichogramma pretiosum, as well as on [F.sub.1] and [F.sub.2] generations of this parasitoid species, under laboratory conditions. Eggs of the factitious host Anagasta kuehniella (Zeller) (Lep., Pyralidae) were glued to blue paper cards, UV-killed and treated by dipping in the aqueous solutions of the pesticides and in distilled water (control) during five seconds. Then, the eggs were exposed to parasitization 1, 24 and 48 hours after the treatment, during a period of 24 hours. Afterwards, the eggs were maintained under controlled conditions at 24 ± 1°C, RH of 70 ± 10% and 12 hour-photophase, until the emergence of parasitoids. Etofenprox, fenitrothion and methidathion are toxic to T. pretiosum, whereas trichlorfon is selective and can be used together with this parasitoid species to control cotton pests. Key words: biological control, natural enemy, parasitoid, pesticides, selectivity. O presente trabalho teve por objetivo avaliar a acao residual dos produtos etofemprox, fenitrotiom, metidatiom e triclorfom sobre adultos de Trichogramma pretiosum, bem como sobre as geracoes [F.sub.1] e [F.sub.2] desse parasitoide, em condicoes de laboratorio. Ovos do hospedeiro alternativo Anagasta kuehniella (Zeller) (Lep., Pyralidae) foram aderidos em cartelas de cartolina azul, inviabilizados sob lampada germicida e tratados por imersao nas solucoes inseticidas e em agua destilada (testemunha) por cinco segundos. Os ovos foram expostos ao parasitismo uma, 24 e 48 horas apos o tratamento, por um periodo de 24 horas, e posteriormente mantidos em camara climatizada a 24 [+ o -] 1[grados]C, UR de 70 [+ o -] 10% e 12 horas de fotofase ate a emergencia dos parasitoides. Etofemprox, fenitrotiom e metidatiom sao prejudiciais a T. pretiosum, enquanto triclorfom e seletivo e pode ser utilizado em associacao com esse parasitoide no controle de pragas da cultura do algodoeiro. Palavras-chave: controle biologico, inimigo natural, parasitoide, pesticidas, seletividade.