Combining lacewings and parasitoids for biological control offoxglove aphids in sweet pepper

ROCCA MARGARITA; MESSELINK GERBEN

JOURNAL OF APPLIED ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 p. 1 - 9

0931-2048

The role of natural enemy diversity in biological pest control has beendebated in many studies, and understanding how interactions amongstpredators and parasitoids affect herbivore populations is crucial for pestmanagement. In this study, we assessed the individual and combined useof two species of natural enemies, the parasitoid Aphidius ervi Haliday, andthe predatory brown lacewing Micromus variegatus (Fabricius), on theirshared prey, the foxglove aphid, Aulacorthum solani (Kaltenbach), onsweet pepper. We hypothesized that the presence of intraguild predation(IGP) and predator facilitation (through induced aphid dropping beha-viour) might have both negative and positive effects on aphid control,respectively. Our greenhouse trial showed that overall, the greatest sup-pression of aphids occurred in the treatment with both the parasitoid andthe lacewing. While the combination of lacewings and parasitoids signifi-cantly increased aphid control compared to the use of parasitoids alone,the effect was not significantly different to the treatment with only preda-tors, although there was a clear trend of enhanced suppression. Thus, thecombined effects of both species of natural enemies were between addi-tive and non-additive, suggesting that the combination is neither positivenor negative for aphid control. High levels of IGP, as proven in the labora-tory, were probably compensated for by the strong aphid suppression pro-vided by the lacewings, whether or not supplemented with some level ofpredator facilitation. For aphid management over a longer time scale, itmight still be useful to combine lacewings and parasitoids to ensure stableand resilient aphid control.