Survivorship of soybean aphid biotypes (Hemiptera: Aphididae) on winter hosts, common and glossy buckthorn
Keywords:Morphs, Aphis glycines, Rhamnus cathartica, Frangula alnus
The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean, Glycine max (L.) Merr., both in Asia where it is native, and in the USA where it is adventive. The rapid spread and establishment of the soybean aphid in the USA since its discovery in 2000 was successful because of extensive soybean production in the Midwest and the wide distribution of common buckthorn, Rhamnus cathartica (L.), its preferred primary winter host. The survivorship of four soybean aphid biotypes on common and glossy buckthorn, Frangula alnus Mill., were compared. Our study showed that nymph oviparae of soybean aphid biotypes 1, 2, 3 and 4 reached adulthood and produced eggs on glossy buckthorn. When comparing morphs between the hosts, greater numbers were recorded on common than glossy buckthorn, with one exception where the number of eggs per bud for soybean aphid biotype 2 was not different between the hosts. We found for the first-time soybean aphid biotypes 2 and 3 apterous males produced on common and glossy buckthorn. Morphological descriptions of live and mounted alate and apterous males are presented.