Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5922152 | Journal of Insect Physiology | 2012 | 12 Pages |
In comparison to other similarly sized mantis species examined in previous studies, Euchomenella macrops has a significantly smaller head, shorter foreleg tibia, but longer prothorax which have been interpreted as specializations for the capture of smaller, slower prey. We tested this conjecture by assessing the rates at which computer generated stimuli elicit visual tracking, approaching, and striking behaviors by adult females. When presented with black disks moving erratically against a white background, strike rate rose progressively as disks enlarged up to 44Â deg (visual angle) if the disks moved rapidly (e.g., 143Â deg/s); at slower speeds (113, 127Â deg/s), smaller disks (<27Â deg) were preferred. When black moved linearly from the visual periphery to visual field center (at 73 or 143Â deg/s) and then stopped, E. macrops struck consistently at disks as small as 5Â deg after movement ceased. E. macrops also struck at higher rates in response to 23Â deg erratically moving (subjective) red (versus subjective blue or green) disks that were luminance matched to a grey background although they tracked all colors at equally high rates. Unlike some other species, E. macrops did not strike at higher rates in response to elongated rectangular stimuli moving parallel (versus perpendicular) to their long axis, although the former elicited higher rates of approaching. An analysis of tracking behavior revealed that virtually all tracking movements were a result of head (versus) prothorax rotation.
Graphical abstractDownload full-size imageHighlights⺠We assessed the responses of the mantis, Euchomenella macrops to animated stimuli. ⺠Predatory strike rate increased with increasing size of erratically moving disks. ⺠Surprisingly, E. macrops struck at small stimuli after they stopped moving. ⺠Small stimuli elicited higher strike rates when moving slowly versus quickly. ⺠Despite a long prothorax, tracking movements were due primarily to head rotation.