TWO PUTATIVE BRIDGEHEAD POPULATIONS OF APHELINUS MALI (HYMENOPTERA: APHELINIDAE) INTRODUCED IN CHINA AS REVEALED BY MITOCHONDRIAL DNA MARKER.

In China, Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) was independently introduced as an endoparasitoid of the woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae) from Japan in 1942 and from the former Soviet Union during 1953- 1955. However, we do not know which introduction of this endoparasitoid plays important role in the control of E. lanigerum in China. To determine the status of this biological control agent in China, we collected 16 populations from 6 provinces (Shandong, Liaoning, Hebei, Shanxi, Xinjiang and Yunnan) and analyzed the 948 mtCOI gene from specimens in these samples. The results revealed that the A. mali in China consisted of 2 cryptic mitochondrial clades including 3 haplotypes, which indicated at least 2 independent introductions of the parasitoid into China. Our results showed that each of the populations that had been introduced into Shandong and Liaoning, respectively, had also established in many regions of China, where they play an important role in the control of E. lanigerum. Therefore it is very likely that both original introductions have served as bridgeheads to establish other populations in China. Genetic analyses together with field surveys should be helpful in the management of the woolly apple aphid. [ABSTRACT FROM AUTHOR]