Implications of phenotypic variation of Myzus persicae (Hemiptera: Aphididae) for biological control on greenhouse pepper plants

Variation in vulnerability to natural enemies, reproductive rate and insecticide resistance among phenotypes of Myzus persicae (Sulzer) has been shown to have the potential to disrupt biological control and IPM of this species, and movement of particularly troublesome phenotypes in international horticultural trade could be cause for concern. Three important components of fitness, vulnerability to parasitoids, reproduction and insecticide resistance were determined in three clones of M. persicae originating from prevalent phenotype populations on pepper crops in greenhouses in British Columbia, Canada. One of these phenotypes appeared to be consistently involved in outbreaks in commercial operations. These clones were also characterized for their DNA microsatellite genotype and compared with genotypes of M. persicae from Europe. The clone involved in outbreaks in commercial greenhouses showed reduced vulnerability to parasitoids, and a higher reproductive rate compared to the other two clones suggesting that these traits may have been involved in outbreaks. As in M. persicae European clones, a higher reproductive rate was correlated with a lack of esterase-based resistance (primarily to organophosphates and, to some extent, to carbamates and pyrethroids). However, microsatellite analysis demonstrated that the three clones investigated in British Columbia had unique genotypes, and therefore there was no evidence for their movement in international trade.