Coloration and morphology of the orchid mantis Hymenopus coronatus (Mantodea: Hymenopodidae)

Abstract

The orchid mantis, Hymenopus coronatus (Insecta: Mantodea), is renown for its visual resemblance to a flower blossom. It has been hypothesised that the 'flowerlike' orchid mantis is an aggressive mimic that attracts pollinators as prey items. This is the first study into the morphology of the orchid mantis that explores this widely discussed hypothesis. We quantified color and shape patterns of orchid mantises that are likely to present visual cues to pollinators. We used spectrometry to measure their overall coloration and geometric morphometric techniques to quantify the shape of their 'petal-like' mid- and hind-legs. This was done for both juvenile and adult female orchid mantises. To investigate how this stimulus may be perceived by a pollinating insect we investigated within-individual color variation using physiological models of hymenopteran vision. Mantises were found to reflect primarily UV- absorbing white. Visual models indicated that within individuals, different body parts did not contrast highly in color. Femoral lobes showed patterns of bilateral symmetry with juveniles expressing similar patterns of shape variation to adults. The results are used to provide specific and testable hypotheses as to how the morphology of the orchid mantis may constitute a signal directed towards pollinating insects.