A comparison of soil particle size and its influence on pit construction, pit morphology and capture success for Myrmeleon diminutus and M. pictifrons was undertaken. Both species constructed pits by the circuitous method, using the forelegs. The forelegs may aid in encouraging soil particles to fall from the forming pit wall and may help to direct soil onto the dorsal surface of the head for subsequent tossing. Both species showed a preference to build in fine soil (<0.3 mm) but the aversion to medium (0.3-0.6 mm) and coarse soil (0.6-1.2 mm) differed. In mixed particle size soil all ant-lion pits were lined with fine soil particles less than 0.3 mm diameter. This improved capture success by delaying the escape of prey and increasing the number of falls to the pit vertex during escape. Body weight was found to be the most important correlate of pit morphology. Pit diameter and pit depth increased linearly and pit angle increased curvilinearly with body weight. The smallest ant-lions optimize trap design by building pits close to the angle of repose of the soil, but larger ant-lions build relatively shallower, less optimal pits.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Zoology
Research Field:	Invertebrate biology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the biological sciences
UTAS Author:	Allen, GR (Associate Professor Geoff Allen)
ID Code:	102694
Year Published:	1985
Web of Science® Times Cited:	27
Deposited By:	Tasmanian Institute of Agriculture
Deposited On:	2015-09-03
Last Modified:	2015-10-06
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