Lady Beetles in New York: Insidious Invasions, Erstwhile Extirpations, and Recent Rediscoveries

Over the past 40 years, the complex of coccinellid (lady beetle or ladybug) species in New York has undergone substantial changes. Primarily, these changes have involved the decline of native species and the increase and spread of adventive species. Species declines have proceeded to the extent that several native species were feared to be extirpated from New York. Here we report that two of these native species, Adalia bipunctata (Two-spotted Lady Beetle) and Coccinella novemnotata (Nine-spotted Lady Beetle), were rediscovered in New York, in 2009 and 2011, respectively, by volunteers and specialists working for the Lost Ladybug Project. We found that the current coccinellid complex in New York is significantly less diverse and has a significantly higher proportion of foreign species compared to the complex in the past. We discuss the potential causes and implications for these shifts and rediscoveries.