Patch choice in the anthophilous ambush predator Phymata americana: improvement by switching hunting sites as part of the initial choice

Abstract

Optimal foraging theory predicts that foragers with an imperfect knowledge of the environment will invest time sampling the foraging area. The ambush bug Phymata americana Melin appertains to this category of foragers because it has shown, in previous studies, apparently nonoptimal behaviour in choosing patches while crawling on the ground. Even so, we hypothesize that, atop the canopy where they normally seek prey, they can easily switch to a better position. To examine this hypothesis and to test the prediction of optimal foraging theory, adult male and female ambush bugs were released in an experimental arena containing six different kinds of patches of Solidago canadensis: (1) normal, leafy stems with inflorescences, (2) bare stems without inflorescences, (3) leafy but deflowered stems, (4) normal stems with ambush bugs of the opposite sex in the inflorescences, (5) normal stems with dead house flies (Musca domestica) (prey) hanging over the flower, and (6) normal stems with dead honeybees (Apis mellifera) (prey) hanging over the flower. The bugs showed only weak discrimination in choosing a stem from the ground. However, once atop the canopy (stems or inflorescences), the bugs switched quickly to other patches, significantly improving their situation. These results suggest that this ambush predator has some ability to recognize not only vegetation and floral cues, but also the presence of other insects in flowers, i.e., prey and the opposite sex. Sexual diethism is also indicated.

Negative impacts of a vertebrate predator on insect pollinator visitation and seed output in Chuquiraga oppositifolia, a high Andean shrub

“…In our view central-place foragers and sit-and-wait predators such as lizards, some spiders, and inflorescence-inhabiting predatory insects (e.g. Morse 1986;Greco and Kevan 1995;Chase 1998;Schmalhofer 2001;Suttle 2003), are more likely to cause significant behaviour-mediated indirect effects on plants than predators that move continuously. Support for this prediction was documented by Schmitz and Suttle (2001), who compared the direct and indirect effects of sit-and-wait, sit-and-pursue, and actively hunting spiders on grasshoppers and plants.…”

“…Louda 1982; Kevan and Baker 1983;Morse 1986;Caron 1990; Greco and Kevan 1995;Craig et al 2001;Dukas 2001aDukas , 2001bDukas and Morse 2003) and birds, particularly insectivorous flycatchers (Tyrannidae) (Ambrose 1990). Nevertheless, research on plant-pollinator interactions has been conducted almost exclusively within the framework of two trophic levels (but see Louda 1982;Willmer and Stone 1997;Altshuler 1999), with carnivores being neglected in spite of potential negative effects on pollinator visitation patterns (but see Dukas 2001aDukas , 2001bDukas and Morse 2003;Suttle 2003).…”

Effects of perceived danger on flower choice by bees

“…This belief is in disagreement with the long list of species that prey on bees, most notably, bee eaters (Meropidae) (Fry 1983), Old and New World flycatchers (Muscicapidae and Tyrannidae) (Ambrose 1990), bee‐wolves ( Philanthus spp.) (Evans & O’Neill 1988), some social wasps (Evans & Eberhard 1970; De Jong 1990), crab spiders (Thomisidae) (Morse 1981; Morse 1986), predacious bugs (Hemiptera) (Balduf 1939; Greco & Kevan 1995) and praying mantids (Mantidae) (Caron 1990). Another common assertion is that the nonreproducing workers of social bees should ignore predation risk because worker predation would not affect colony reproduction.…”

Crab spiders affect flower visitation by bees

“…First, numerous animals prey on bees. These include bee eaters (Meropidae) (Fry 1983), Old and New World flycatchers (Muscicapidae and Tyrannidae) (Ambrose 1990), bee‐wolves ( Philanthus spp) (Evans and O'Neill 1988), a few species of social wasps (Evans and Eberhard 1970, De Jong 1990), crab spiders (Thomisidae) (Morse 1981, Morse 1986a), predacious bugs (Hemiptera) (Balduf 1939, Greco and Kevan 1995) and praying mantids (Mantidae) (Caron 1990). Second, theoretical analyses indicate that workers of social bees should consider predation risk while making foraging choices, albeit to a lesser degree than solitary bees (Clark and Dukas 1994, Dukas and Edelstein‐Keshet 1998).…”