EXTRAFLORAL NECTAR FEEDING BY LADYBIRD BEETLES (COLEOPTERA, COCCINELLIDAE)

Coccinellid beetles belonging to 41 species in 19 genera and 5 of the family's 6 coccinellid subfamilies were observed in the United States, China, Japan, and Korea, or are reported in the literature to feed on the extrafloral nectar of 32 plant species in 23 genera and 15 famili es. Extrafloral nectar feeding by coccinellids occurred throughout the world in diverse natural and man-made habitats. Since ladybird beetle s are, at times, common and occasionally abundant visitors to extraflo ral nectaries, they could reduce insect herbivores of the plants that bear the glands, much as do many extrafloral nectar feeding ants. Most extrafloral nectary feeding by ladybird beetles, however, was not obs erved in the presence of prey, nor usually where ants were abundant. L adybird beetles were less frequent and less constant visitors to extra floral nectaries than were ants, and appear by contrast to be poor mut ualists to extrafloral nectary-bearing plants. Extrafloral nectar seem s to be an important energy source for coccinellids in the absence of prey. It probably enhances ladybird beetle survival and may maintain t hem in the habitat, to feed on insect herbivores as they appear.