Effects of density and hunger on the spatial distribution and pit construction behaviour of the antlion larvae (Myrmeleon spp.)

Abstract

The antlion larvae are sessile predaceous larvae, which depend on active prey for their food. They dig conical pit in loose fine sand and remain at the bottom of their pits with their long piercing jaws from where they seize and remove the body fluids of the ant and other arthropods that slide into their trap. The effects of hunger and density on the spatial distribution and pit construction by the larvae were studied for the three instar stages in fine and coarse sand textures of particles size of <540 μm and <1200 μm respectively.Twenty four (24) Iron trays of 25cm² each filled with sand to the depth of 20cm were used in the study.The result of the findings reveals that with the increase in density, there was an increased in spatial uniformity and the pits became uniformly distributed. The diameters of the pit were not statistically affected by the changes in the larval density. There was difference between the total number of pits constructed between sand textures and not between the larval instars, in addition, nearest neighbor distance decreases with increase in density and with no effect on pit diameter. Pit diameter increases with hunger level and Antlion move pit to reducedisturbances and to improve food supply. The result analysis showed significant differences in the mean number of pits constructed between densities, sand texture and larval instars at P< 0.01 but none between fed and larval instar.

Keywords: Antlion, Construction, Density, Distribution, Hunger, Larvae, Pit.