Behavioral Mimicry in Insects

Rettenmeyer [7] predicted that behavioral mimicry would be especially important among mimics of Hymenoptera, notably wasps and ants, because the behavior of their models is so conspicuous. Many mimetic invertebrates use behavioral cues to enhance their mimicry, and this is particularly remarkable when mimics and models are not closely related and have quite different morphologies. Good examples, which are included here because they mimic insects although they are not themselves insects, are ant-mimicking spiders, notably salticids of the genus Myrmarachne (Salticidae). They bring their front legs forward and wave them about to mimic the long antennae of ants (Hymenoptera: Formicidae) and thus also give the impression of having just six legs [3,13,44]. However, when alarmed, the spiders run off on all eight legs, so they retain full function of their front legs. The evolution of precise antlike behaviors in myrmecomorphic species might be predicted given that behavior is often identified as the most conspicuous feature of ants [7]. Some hoverflies (Diptera: Syrphidae), which mostly possess quite short antennae, also mimic the long antennae of social wasps (Hymenoptera: Vespidae) by bringing their front legs forward [45] while others (Eristalis tenax) mimic honeybees (Hymenoptera: Apidae) by dangling their legs in flight above flowers as if they are transferring pollen into pollen baskets (personal observation). Another example of leg-dangling behavior is shown by a syntomid moth (Macrocneme), mimicking the habit of its fossorial wasp model [46]. Carpenter [35] cited examples of flies that mimic the antennal behavior shown by stinging hymenoptera; they do this by waving the anterior pair of legs.

He suggested that the vibrating of antennae is part of an advertisement of aposema-tism by stinging insects. Some hymenopterans have white markings on the antennae that further highlight this warning behavior, and this is mimicked by syntomid moths. Cott [46] also described many examples of mimics that, when captured, behave as if they are likely to sting by curving the abdomen; these include forest dragonflies (Microstigma maculatum); a moth belonging to the genus Phaegoptera; a staphylinid beetle (Xanthopugus); and a longicorn beetle (Dirphya). The last example was described in detail by Carpenter and Poulton [47]; they commented that it was so impressive, they were reticent to handle the beetle!

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