Patch choice in ambush predators: Plant height selection byMisumena vatia(Araneae, Thomisidae) andPhymata americana(Heteroptera, Phymatidae)

:Females of the crab spider (Misumena vatia) and adult males and females of the ambush bug (Phymata americana) were released in an experimental arena containing three different kinds of patch (an individual flowering stem) of Solidago canadensis stems (high:75 cm, medium: 35 cm and short: 15 cm). The crab spiders showed a significant preference for short stems but the ambush bug did not choose any height more often than predicted by chance. The time spent choosing was significantly longer for the spiders than for the bugs (29 minutes versus 18 minutes). These results are discussed in terms of costs in time and energy and as they suggest that spiders are more careful when choosing. The differences may reflect the greater penalty spiders would suffer from making wrong choices compared to the bugs, and suggest that travel costs for the spider are not negligible.