Prey Capture by the Crab Spider Misumena vatia (Clerck) (Thomisidae) on Three Common Native Flowers

Abstract

The capture methods and prey of crab spiders M. vatia (Clerck) hunting on pasture rose (Rosa carolina L.), common milkweed (Asclepias syriaca L.) and goldenrod (Solidago juncea Ait.) were compared. Individual spiders occupied milkweed and goldenrod infloresences significantly longer than rose flowers. They also captured significantly larger biomasses of prey on milkweed and goldenrod than on rose. During the day, spiders captured a larger biomass of prey on goldenrod than on milkweed; when nighttime captures on milkweed (entirely moths) were added, it was the most profitable feeding site. The low captures of prey on pasture rose were partly a consequence of the short period during which it attracted insects each day. Overall, bumblebees (Bombus spp.) were the most important prey in terms of biomass, although small syrphid flies (Toxomerus marginatus) were the most frequently captured prey. The only other frequently captured items were honeybees (Apis mellifera) and moths, both primarily on milkweed. Only on milkweed was there sign of noturnal hunting. Spiders hunting on roses invested considerable time finding new flowers each day and also took longer to process prey than did spiders on other flowers.