Seletividade fisiológica de inseticidas a Vespidae predadores de Ascia monuste orseis

Abstract

Resumo -Este trabalho objetivou estudar a seletividade dos inseticidas carbaril, deltametrina, paratiom metílico, permetrina e triclorfom em relação a Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) e a seus predadores Brachygastra lecheguana Latreille e Protonectarina sylveirae (Saussure) (Hymenoptera: Vespidae). Por meio de curvas de concentração-mortalidade e das concentrações letais para 90% da população (CL 90 Termos para indexação: Brachygastra lecheguana, Protonectarina sylveirae, controle de insetos, controle biológico. Insecticide physiological selectivity to Vespidae predators of Ascia monuste orseisAbstract -This work aimed to study the selectivity of the insecticides carbaryl, deltamethrin, methyl parathion, permethrin and trichlorfon in relation to Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) and to their predators Brachygastra lecheguana Latreille and Protonectarina sylveirae (Saussure) (Hymenoptera: Vespidae). Based on concentration-response curves and lethal concentrations for 90% of the population (LC 90 ), the differential selectivity index (DSI 90 ), relative toxicity index and relative tolerance index (ReTI 90 ) were calculated. Methyl parathion and trichlorfon were selective to B. lecheguana (DSI 90 = 2.83 and 1.75) and P. sylveirae (DSI 90 = 2.95 and 3.59) against A. monuste orseis. Deltamethrin and permethrin were selective to P. sylveirae (DSI 90 = 1.98 and 2.70) against A. monuste orseis, but weren't selective to B. lecheguana (DSI 90 = 0.21 and 0.64). B. lecheguana was less tolerant to deltamethrin, permethrin and trichlorfon than P. sylveirae (ReTI 90 = 9.36, 4.23 and 2.05), but the opposite was observed to carbaryl (ReTI 90 = 0.14). These two predators showed similar tolerance to methyl parathion (ReTI 90 = 1.04). Concentration-response curves of carbaryl, permethrin and trichlorfon to both predators, deltamethrin to B. lecheguana, and methyl parathion to P. sylveirae, showed greater slopes than these curves to A. monuste orseis.Index terms: Brachygastra lecheguana, Protonectarina sylveirae, insect control, biological control.(1) Aceito para publicação em 24 de maio de 2001.(2) Universidade Federal de Viçosa, Dep. de Biologia Animal, CEP 36571-000 Viçosa, MG. Bolsista do CNPq. E-mail: picanco@mail.ufv.br IntroduçãoAs brássicas (crucíferas) constituem a família mais numerosa em termos de espécies oleráceas, totali-

Effect of selectivity of herbicides and plant growth regulators used in sugarcane crops on immature stages of Trichogramma galloi (Hymenoptera: Trichogrammatidae)

“…At the egg-larva stage, the parasitoids tend to be more sensitive, probably because of the longer period of penetration of the product through the chorion of the host egg until emergence and also increased activity of the larvae, when compared to the prepupal and pupal stages, which corroborates the results obtained by Carvalho et al (2001). Furthermore, the penetration ability of the products depends on their physicochemical properties, such as their lipophilicity (Crespo et al 2002), and also the properties of the host, which vary depending on the species, age and stage of development of the egg (Cônsoli et al 1999a, b).…”

Seletividade de inseticidas a Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) e Cotesia sp. (Hymenoptera: Braconidae) inimigos naturais de Ascia monuste orseis (Godart, 1818) (Lepdoptera: Pieridae)

“…(Hymenoptera: Braconidae) (PENTEADO-DIAS, 1986, GOBBI et al, 1989e 1990, RENESTO & TERADA, 1992, CAVALCANTE et al, 1996. Entre os principais inseticidas utilizados no controle de A. monuste orseis em brássicas, estão o carbaril, a deltametrina, o paratiom metílico, a permetrina e o triclorfom (CRESPO et al, 2001). Apesar do curuquerê da couve ser uma praga de registro antigo (SILVA et al, 1968) e de sua importância como praga em culturas de brássicas, pouco se conhece sobre o grau de seletividade fisiológica desses inseticidas aos seus inimigos naturais (CRESPO et al, 2001).…”

Physiological selectivity of insecticides from different chemical groups and cuticle thickness of Protonectarina sylveirae (Saussure) and Brachygastra lecheguana (Latreille)

“…Deltamethrin was highly toxic to B. lecheguana and P. sylveirae causing 100% mortality (Galvan et al, 2002). B. lecheguana tolerance to deltamethrin compared to P. sylveirae differs from that obtained by Galvan et al (2002) and Crespo et al (2002). Results show that the cuticle thickness of B. lecheguana is twice as thick as P. sylveirae.…”