Selection for evasive mimicry imposed by an arthropod predator

It has long been hypothesized that a species that is relatively easy to
catch by predators may face selection to resemble a species that is harder
to catch.  Several experiments using avian predators have since
supported this “evasive mimicry” hypothesis.  However, the sudden
movement of artificial evasive prey in each of the above experiments may
have startled the predators, generating an avoidance response unrelated to
difficulty of capture. Additionally, in the above experiments, the
catchability of prey was all or nothing, while in nature predators may
occasionally catch evasive prey or fail to catch slower species, which
might inhibit learning. Here, using mantids as predators, we conducted an
experimental test of the evasive mimicry hypothesis that circumvents these
limitations, using live painted calyptrate flies with modified evasive
capabilities as prey. We found that mantids readily learned to avoid
pursuing the more evasive prey types. Warning signals based on evasiveness
and their associated mimicry may be widespread phenomena in
nature.  These findings not only further support its plausibility
but demonstrate that even arthropod predators can select for it.