The present paper presents the record of an alien aphid species new to China, which was found in Beijing on black locust trees (Robinia pseudoacacia Linn.):Appendiseta robiniae (Gillette, 1907). It is commonly found in some areas of North America on black locust trees, and already found in the Western Palaearctic. The paper describes the characteristics of alate viviparous females, oviparous females, and alate males. Finally, we discuss the potential importance of this species as a pest of black locust in China and other host plants. The use of field pictures can help recognize various aphid species.