Parasitism of several aphid species by Aphelinus asychis (Walker) and Aphelinus albipodus Hayat and Fatima

Aphelinus asychis (Walker) and A. albipodus Hayat and Fatima from locations in Asia and Africa (hereafter referred to as strains) were tested for thei r abilities to develop from egg to mummy and from mummy to adult stages in 16 common aphid species. Strains of A. asychis from China, Kazakhstan, and Morocco developed to the mummy stage in 15, 14, and 15 aphid species, respe ctively. There was no difference in mean adult emergence rate between strai ns. An ordinal rating system of none, low, and high was used to compare the extent of mummy formation among strains. Mummy formation ratings were sign ificantly correlated for comparisons of strains from China and Kazakhstan ( r = 0.68) and China and Morocco (r = 0.63), but not for strains from Kazakh stan and Morocco (r = 0.40). Correlations of ratings for strains from proxi mate geographical locations were no larger than for strains from more widel y separated locations. There was no difference in mean adult emergence rate among strains of A. albipodus from China (Altai, Pingluo, and Urumqi) and Caucasus (Buddenousk). Strains from Altai, Urumqi, Pingluo, and Buddenousk developed to the mummy stage in 13, 12, 12, and 10 species, respectively. M ummy formation ratings for all pairs of strains were significantly correlat ed. The largest correlation, 0.83, was for the comparison of the Urumqui an d Altai strains, which were closest together geographically. The smallest c orrelations, ranging from 0.45-0.60, were for comparisons involving the mos t distant (Buddenousk) strain with Chinese strains.