Abstract:
Aphidius colemani Viereck (Hymenoptera: Braconidae) is a solitary endoparasitoid
used for biological control of many economically important pest aphids. Given its
widespread use, a vast array of literature on this natural enemy exists. Though often highly
effective for aphid suppression, the literature reveals that A. colemani efficacy within
greenhouse production systems can be reduced by many stressors, both biotic (plants,
aphid hosts, other natural enemies) and abiotic (climate and lighting). For example, effects
from 3rd and 4th trophic levels (fungal-based control products, hyperparasitoids) can
suddenly decimate A. colemani populations. But, the most chronic negative effects
(reduced parasitoid foraging efficiency, fitness) seem to be from stressors at the first
trophic level. Negative effects from the 1st trophic level are difficult to mediate since
growers are usually constrained to particular plant varieties due to market demands. Major
research gaps identified by our review include determining how plants, aphid hosts, and
A. colemani interact to affect the net aphid population, and how production conditions such
as temperature, humidity and lighting affect both the population growth rate of A. colemani
and its target pest.