Functional response of the predaceous mites Amblyseius largoensis and Euseius concordis when feeding on eggs of the cashew tree giant whitefly Aleurodicus cocois

Abstract The giant whitefly, Aleurodicus cocois, is one of the main pests of cashew trees around the world. In the present study we evaluated the biological potential of the predaceous mites Amblyseius largoensis and Euseius concordis against A. cocois. The consumption and functional responses to prey egg densities of A. largoensis and E. concordis were investigated in laboratory experiments. Logistic regression indicated that both predators exhibited a type II response to prey eggs, and the eggs consumption increased with egg density up to a maximum, after which it slowly decreased. The value of the attack rate (a′) was higher for A. largoensis than that for E. concordis, but the handling time (Th) did not differ between the two predators. The predicted maximum daily consumption was 35 eggs for A. largoensis and 32 eggs for E. concordis. Our results indicate that A. largoensis and E. concordis could be effective biocontrol agents of the cashew tree giant whitefly, especially in conditions of low pest pop...