Impacts of differences in nutritional quality of wingless and winged aphids on parasitoid fitness

Abstract

Winged aphids are described as hosts of lesser quality for parasitoids because a part of their resources is used to produce wings and associated muscles during their development. Host lipid content is particularly important for parasitoid larvae as they lack lipogenesis and therefore rely entirely on the host for this resource. The goal of this study was to determine to what extent winged and wingless aphids differ from a nutritional point of view and whether these differences impact parasitoid fitness, notably the lipid content. We analysed the energetic budget (proteins, lipids and carbohydrates) of aphids of different ages (third instars, fourth instars and adults) according to the morph (winged or wingless). We also compared fitness indicators for parasitoids emerging from winged and wingless aphids (third and fourth instars). We found that in third instars, parasitoids are able to inhibit wing development whereas this is not the case in fourth instars. Both winged instars allow the production of heavier and fattier parasitoids. The presence of wings in aphids seems to have little effect on the fitness of emerging parasitoids and did not modify female choice for oviposition. Finally, we demonstrate that , used as a biological control agent, is able to parasitize wingless as well as winged, at least in the juvenile stages. If the parasitism occurs in third instars, the parasitoid will prevent the aphid from flying, which could in turn reduce virus transmission.

Cascading effects of caffeine intake by primary consumers to the upper trophic level

“…Because the concentration of caffeine in the sap of most plants on which this aphid feeds is unknown, these concentrations were chosen according to preliminary results on aphid parasitoids (Tougeron et al, unpublished data), and to previous work on Drosophila melanogaster (Nikitin et al, 2008;Keebaugh et al, 2017) that are comparable in size with large aphids and aphid parasitoids. To feed aphids, 600 μl of the solution were deposited on the surface of a small sterilized plastic petri dish (Ø 5 cm) and it was immediately covered with a piece of stretched parafilm to create a thin membrane through which aphids could feed (Pirotte et al, 2018;van Emden and Wild, 2020). Thirty adult female aphids were taken from the cultures and placed on a fresh Brassica rapa (Brassicales: Brassicaceae) leaf until they deposited larvae.…”

Biocontrol in practice in Canadian floricultural greenhouses

“…Secondly, adults of Aphidius spp. are extremely strong flyers and females can fly 16 meters within 24 hours after release in search of aphids (Langhof et al, 2005, Jennifer et al, 2018. Thirdly, Aphidius spp.…”