Seasonal changes in habitat preference by Coleomegilla maculata: Implications for Colorado potato beetle management in potato

Seasonal abundance, dispersal, and overwintering of the la-spotted ladybird beetle, Coleomegilla maculata (DeGeer), in the mid-Atlantic states were in vestigated to assess the potential to manipulate the habitat of this predat or to increase its impact on Colorado potato beetle, Leptinotarsa decemline ata (Say), management in commercial potato plantings. C. maculata populatio ns were highest in corn fields through August, and overwintering aggregatio ns were found most commonly in habitats adjacent to these fields. Although adult and larval populations of C. maculata were synchronized with first-ge neration potato beetle eggs and small larvae, they were concentrated in whe at rather than potato fields because most of the potato plants had not yet emerged when C. maculata adults dispersed fi om their overwintering sites. The subsequent generation of C. maculata tended to aggregate in corn rather than potato in late May and early June. Therefore, given the current mixtu re of crops as well as climatic and marketing limitations on planting date for potatoes, the potential for habitat manipulation to increase the impact of C. maculata on Colorado potato beetle management in potato in the mid-A tlantic states appears to be limited, (C) 2000 Academic Press.