COCCINELLA NOVEMNOTATA IN NORTHEASTERN NORTH-AMERICA - HISTORICAL OCCURRENCE AND CURRENT STATUS (COLEOPTERA, COCCINELLIDAE)

A review of the literature documents that the native lady beetle Cocci nella novemnotata Herbst (C9) was once common in the northeastern Unit ed States and Canada. Despite extensive recent fieldwork and surveys f or coccinellids, only five collection records of C9 in the Northeast h ave been located since the mid-1980s. Its apparent decline in numbers and possible local extirpation could be the result of factors such as changes in land-use and cropping patterns, decline in aphid population s, parasitism, or disease. The factor most often suggested is possible adverse effects from the Old World C. septem-punctata L. (C7), whose establishment in North America was detected in 1973. New World populat ions of C7 may have resulted from previous releases for the biological control of aphids or an unintentional importation with commerce. With out a cause-and-effect relationship having been established, proposed detrimental impacts of C7 on native coccinellids are based solely on a necdotal evidence and speculation. Even though C7 was extensively reco lonized in North America by biological control specialists, the C7 pro ject does not typify classical biological control. If C7 has had a neg ative effect on C9, it is more appropriately considered displacement o f an indigenous species by a polyphagous nonindigenous species than an example of unintended effects of classical biological control.