Differences in prey recognition and eye allometry in three species of praying mantis

Initial research on mantid prey recognition has revealed that some mantids simultaneously assess a number of visual stimulus parameters to determine whether or not an object meets a sufficient number of criteria to be classified as prey. However, it is not known whether these object recognition abilities differ systematically between species due to variance in overall size and/or eye morphology. In this study we assessed the prey recognition abilities of and collected allometric data on three very different species of mantid: Tenodera aridifolia sinensis, Mantis religiosa, and Cilinia humeralis. Our findings reveal some fundamental similarities and surprising differences in prey recognition. All species responded appetitively to (i.e. struck at) elongated stimuli moving parallel to their long axis but ignored the same stimulus rotated 90 deg; however, the sizes and speeds at which this orientation preference was made differed among species. Similarly, all three species struck at erratically moving compact stimuli (circles and squares) but displayed species differences in the speeds and sizes that they preferred; the smallest species (M. religiosa) preferred compact stimuli several times larger than did the largest species (T. a. sinensis). Although these behavioral similarities among species may suggest fundamental similarities in their visual systems, neural differences in eye morphology may explain differences in prey recognition abilities.