Discovery of a transitional host of the soybean aphid, Aphis glycines (Hemiptera: Aphididae), in northeastern China

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a significant pest in soybean-growing regions and is native to eastern Asia. The life cycle of the aphid is complex with different physical forms and two types of host plants that are targeted. The winged females are produced on buckthorn (Rhamnus spp.) in the spring and migrate into the soybean fields approximately 2 weeks before the soybeans emerge. This phenomenon suggests that A. glycines could infest other hosts (transitional hosts) during the period before soybean emergence. To verify the availability of transitional hosts, eggs of aphids were collected from Rhamnus davurica Pallus (Rhamnales: Rhamnaceae), the hatched aphids were reared, and the subsequent winged generation was transferred onto several candidate hosts. The possible transitional hosts of A. glycines were Capsella bursa-pastoris (L.) Medic (Capparales: Brassicaceae), Metaplexis japonica (Thunb.) Makino (Gentianales: Asclepiadaceae), and Artemisia scoparia Waldst. et Kit (Asterales: Compositae). The aphids found on M. japonica were identified as A. glycines, and the aphids found on the other hosts were identified as the cotton aphid, Aphis gossypii Glover. Thus, M. japonica is likely the transitional host of A. glycines.