Does parasitoid pressure elicit defensive polyphenism in the green peach aphid?

Aphids are capable of adapting to parasitoid pressure in the absence of sexual reproduction using epigenetically controlled polyphenism. Asexual lineages of aphids could thus become resistant to parasitoids over time and with repeated exposure, hampering biocontrol efforts that rely on parasitoid wasps. Prior to this study, wing polyphenism and reproductive polyphenism had been reported as parasitoid-adaptive responses in asexual lineages of at least two species of aphids, but it remained unclear whether parasitoid exposure could induce other defensive polyphenisms. Using a rigorous, replicated experimental evolution design, we aimed to induce adaptive polyphenisms in the green peach aphid, Myzus persicae Sulzer, through serial exposures of single asexual lines to the parasitoid Aphidius colemani Viereck over four consecutive generations. We attempted to measure changes in parasitoid susceptibility, reproductive schedule, body size, and production of pink or alate offspring compared to ...