Selection for pesticide resistance in Aphytis

Abstract

High levels of azinphosmethyl resistance, ca × 10 of a laboratory stock, were discovered in a field population of Aphytis lingnanensis Compere (Hymenoptera: Aphelinidae) parasitizing the California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae), in a heavily sprayed citron orchard. Nine selections for increased resistance led to an initial loss of variability with no significant gains in resistance. Eight additional selections increased resistance to ca 4 times that of the source population, and variability to an extent indicating potential for further progress. Additional selections of this stock by the male selection method resulted in further improvement and field releases of the resistant strain. Initial levels of permethrin tolerance were ca 1.9 times higher than those of the susceptible population. LC50 values were only marginally increased by 13 selections, but a marked increase in the proportion of highly resistant individuals pointed to potential for further progress. Exposure to the insecticides had no observable sub‐lethal after‐effects on rates of progeny production by survivors and on the sex ratio and developmental period of offspring.

From Evolutionary Aspects of Zoophytophagy to Biological Control

“…The first successful examples of genetic improvement of biocontrol agents were intended to increase their pesticide resistance (Hoy and Knop, 1981;Hoy, 1985Hoy, , 1986Hoy, , 1990Rosenheim and Hoy, 1988;Havron et al, 1991). More recently, intraspecific behavioral variations are of interest to researchers especially in nematodes (Segal and Glazer, 2000;Shapiro-Ilan et al, 2003), mites (Pels and Sabelis, 1999;Jia et al, 2002;Maeda and Liu, 2006;Nachappa et al, 2010Nachappa et al, , 2011, coccinelids (Tourniaire et al, 2000;Lommen et al, 2008;Seko and Miura, 2009;Adachi-Hagimori et al, 2011) and parasitoid wasps (Baya et al, 2007;Kruitwagen et al, 2018).…”