عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Lack of quality control methods during the mass rearing of natural enemies may lead to failures in biological control. Body size has important effects on fitness components of parasitoids, and often use as a standard measure of quality control. In the present study, the most appreciate morphological feature that provides the best correlation with body size and egg load in a sexual population of the parasitoid wasp, Lysiphlebus fabarum (Marshall) was determined, when females reared on different nymphal instars of the host aphid, Aphis fabae Scopoli. The experiments were performed under standardized conditions in a growth chamber (21 ± 1°C, 60–70% RH, and 16L : 8D), and candidate metrics were head width, length of the right forewing, and length of the right hind tibia. According to results, head width emerged as the most suitable proxy for total body length of females that were reared in the 2nd nymphal instar (the most suitable host growth stage for mass rearing), while length of the right forewing yielded the highest correlation with total body length, when the data of wasps reared in all four nymphal instars were pooled. Egg load increased linearly with body length across all host growth stages, and the forewing length had the highest correlation with females reared in all four nymphal instars, so it may serve as a better predictor of egg load than other measurements. The results suggest that forewing length can be used as a proxy of quality control in mass rearing of this population of L. fabarum.