Pitfall vs fence traps in feeding efficiency of antlion larvae

Abstract

Larvae of pit-building antlions are expected to be more efficient at capturing prey than those of non-pit-builders. To test this prediction, feeding behaviors were compared in the same experimental conditions among pit-building Baliga micans and Myrmeleon bore, and non-pit-building Distoleon contubernalis. The number of prey eaten did not differ between species. D. contubernalis larvae used the walls of the experimental chamber as fence traps to capture prey. In the field, they were also found near edges of natural barriers, such as rocks, stones, tree roots, and plant stems. Artificial pitfall traps captured more arthropods near the edges of fences than farther from them. Larvae of the two pit-building species were located in the central part of the experimental chamber. In their natural habitats, the number of arthropods captured by artificial pitfall traps increased with pit size; thus, larger pits may be more efficient for capturing prey. In conclusion, pit-building and non-pit-building antlion larvae are both efficient hunters; the former hunt efficiently by making larger pitfall traps, and the latter do so by waiting for prey at the edge of the natural fences along which arthropods walk.