Effects of a Bt-based insecticide on the functional response ofCeraeochrysa cinctapreying onPlutella xylostella

• Main Author: Oliveira Pimenta, Isabela Cristina de
• Publication Date: 2020
• Other Authors: Silva Nunes, Gilmar da [UNESP], Magalhaes, Gustavo Oliveira de [UNESP], Santos, Nathalia Alves dos, Pinto, Matheus Moreira Dantas [UNESP], De Bortoli, Sergio Antonio [UNESP]
• Format: Article
• Language: eng
• Source: Repositório Institucional da UNESP
• Download full: http://dx.doi.org/10.1007/s10646-020-02244-x; http://hdl.handle.net/11449/195483
• topic: Bacillus thuringiensis; Chrysopids; Integrated pest management; Diamondback moth; Trophic interactions

Plutella xylostella, is the main pest infestingBrassicacrops, and products based onBacillus thuringiensis(Bt) are frequently used in strategies for its biocontrol. The present study aimed to evaluate whether a Bt-based bioinsecticide affects the predation behavior ofCeraeochrysa cinctawhen preying onP. xylostella. Three larval instars of the predator and the eggs and second-instar larvae of the moth were used, with the prey either untreated or treated with a Bt-based product (Xentari (R)). Results showed that, the first larval instar ofC. cinctapresented a type II functional response when preying upon untreated eggs, and a type III response when preying upon Bt-treated eggs, while the second and third instars presented type II and III responses, respectively, in both situations. The predator's first and third larval instars presented a type II functional response when preying upon untreated larvae and a type III response when preying upon Bt-treated larvae. However, the predator's second-instar larvae showed a type II response in both treatments. The results obtained allowed us to conclude that the Bt-based insecticide tested affects the predation behavior of the first-instar larvae ofC. cinctaon eggs and of both the first- and third-instar larvae of this predator onP. xylostellalarvae.