9407165 Oswald Pit-building antlions have fascinated generations of amateur and professional biologists with their intriguing behavior of building conical pit-fall traps in loose sand or soil to capture small ground-walking prey. These animals are the larvae of a very successful group of approximately 1700 species of small to medium sized insect predators assigned to the family Myrmeleontidae. It has been suggested that an important factor in the diversification of this group of insects was the development by their larvae of the ability to adapt to living in loose granular substrata, particularly sand. These substrata may have provided a relatively unoccupied ecological zone or niche into which antlions could speciate because relatively few other animals had previously been able to effectively utilize such environments. The research supported by this grant will test this empty niche hypothesis by examining the distributions of morphological characters among numerous species of antlions and other closely related insects. Evidence supporting the hypothesis will have been found, if the first appearance of characters that adapt antlions to a life in granular substrata correlates with the origin of this group. %%% This study will provide important information for improving antlion classification, interpreting historical (phylogenetic) relationships among major groups of antlions and related groups, and studying the origin and development of animal behaviors. The study is one component of a longer-term research program aimed at improving our knowledge of relationships among the 17 families of the insect order Neuroptera (lacewings), an important group of predatory insects that includes several subgroups that are of interest for their potential use in the biological control of crop and ornamental plant pests. ***
