Selectivity of insecticides with two active ingredients on the parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

• Autor(a) principal: Paiva, Ana Clara Ribeiro de
• Data de Publicação: 2020
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/11/11146/tde-16072020-124633/
• topic: Biological control; Controle biológico; Integrated pest management; Manejo integrado de pragas; Pesticida; Pesticide; Toxicidade; Toxicity

The integrated use of chemical and biological control is possible based on the Selectivity tests, as proposed by the IOBC/WPRS. However, it is also important to evaluate further than the lethal effect, as proposed by this organization, assessing other parameters that can alter the efficacy of a natural enemy in the field. Based on this necessity and the importance of the parasitoid wasp Trichogramma pretiosum on biological control programs worldwide, the objective of this study was to evaluate the effects of ready-mix insecticides on different life stages of the parasitoid, following the IOBC/WPRS recommendations, and also considering the sublethal effects. Therefore, the following tests were performed on two generations of the parasitoid: (i) effects of insecticides on pupae immersed in insecticide solution (ii) effects of insecticides on pupa sprayed with insecticide solution (iii) effect of insecticides on adults in contact with dried-residues on Ephestia kuehniella eggs (iv) effects of insecticdes on adults in contact with dried-residues on soybean leaves (v) effects of insecticide on flight capacity when pupae and adults were exposed to the dried-residue (vi) duration of insecticides harmful activity. All the insecticides tested affected somehow at least one of the parameters evaluated in all the tests, showing how important it is to carefully use ready-mix insecticides on IPM programs. Regarding the duration of the harmful activity, six out of the seven insecticides tested were classified as short-lived, and only cyproconazole + thiamethoxam was classified as slightly persistent.