Submitted to: Annals of the Entomological Society of America
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/23/2010
Publication Date: 7/1/2010
Publication URL: DOI: 10.1603/AN09166
Citation: Kim, H., Hoelmer, K.A., Lee, W., Kwon, Y., Lee, W. 2010. Molecular and morphological identification of the soybean aphid and other Aphis species on the primary host, Rhamnus davurica, in Asia. Annals of the Entomological Society of America. 103(4):532-543. Interpretive Summary: A decade ago the Asian soybean aphid was introduced into North America, and it has since become the most serious pest of soybeans in the US. In its native range of northeastern Asia, the aphid undergoes an obligatory seasonal host plant alternation between soybean and its winter host, Dahurian buckthorn. Foreign exploration in Asia is underway to identify important natural enemies of the aphid on its summer and winter hosts that could be released against the aphid in the US. However, it is extremely difficult to tell soybean aphid from its close relatives that also occur on buckthorn, complicating the identification of specific natural enemies for further research. We used two molecular markers obtained from aphid genes to distinguish soybean aphid from other similar species, and in the process we confirmed the existence of two new and undescribed aphid species that occur in mixed populations together with soybean aphid on buckthorn in Asia.
Technical Abstract: The soybean aphid, APHIS GLYCINES Matsumura, was recently introduced into North America where it has become a serious pest of soybeans. In its native range of northeastern Asia, A. GLYCINES undergoes host alternation between the soybean, GLYCINE MAX (summer host), and the Dahurian buckthorn, RHAMNUS DAVURICA (winter host). On the primary host, it is difficult to discriminate A. GLYCINES from coexisting, morphologically similar APHIS species, including seasonal polymorphisms of each species (e.g., gynopara, ovipara, and male). Two widely used molecular markers, the mitochondrial COI ‘barcode’ region (658bp) and the partial tRNA-leucine + cytochrome c oxidase II (tRNA/COII, 702bp), were employed to analyze 31 individuals of APHIS from R. DAVURICA in Asia and compared with 26 closely related APHIS species by Neighbor-Joining method. We found that three different species, A. GOSSYPII and two new and undescribed putative APHIS species, occur together with A. GLYCINES on R. DAVURICA. A study of 40 morphological characters showed that A. GLYCINES, A. GOSSYPII, and one of the new species were quite similar with only a few characters differing significantly between species, e.g., the number of rhinaria on antennal segment III, and transverse bands on abdominal tergites.