Does pirimicarb affect the voracity of the euriphagous predator, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae)?

Abstract

Abstract Pirimicarb is considered a selective and effective insecticide for the control of aphids and whiteflies. Coccinella undecimpunctata L. is a euriphagous predator autochthonous to the Azores, which feeds preferentially on aphids. The voracity of 4th instars and adults (males and females) of C. undecimpunctata using Aphis fabae Scopoli or Aleyrodes proletella L. as preys was evaluated in laboratory, as well as the impact of pirimicarb on the feeding performance using A. fabae as prey. In the absence of chemical treatment and when the prey was A. proletella, satiation lower limits were estimated on a density of 200 individuals in a 24-h period, for 4th instars, adult females and males of C. undecimpunctata. With A. fabae, satiation was attained when 200, 150 and 100 aphids were provided to 4th instars, adult females and males, respectively. C. undecimpunctata exhibited a type II functional response for both prey species. Fourth instars displayed a lower handling time than the adults; handling times of the adults where higher when A. fabae was the prey and attack rates were sex-dependent, that is, attack rate of females was higher on A. fabae while of males was higher on A. proletella. Voracity of C. undecimpunctata was not significantly affected by pirimicarb; therefore, the use of this insecticide can constitute a complementary component for the integrated management of A. fabae.