Dr. Jon Gelhaus of the Academy of Natural Sciences in Philadelphia is studying the biological diversity and taxonomic relationships of crane flies inhabiting desert regions of the North American Southwest. Although crane flies are typically most diverse and abundant in moist habitats, several subgroups show repeated, independent evolution and diversification into arid habitats, a phenomenon apparently unique to the American Southwest in this otherwise worldwide group of insects. Three main objectives are being pursued: (1) Define the species subgroups within the crane fly subgenus Lunatipula of genus Tipula in the northern hemisphere, from which nearly all of the desert crane fly species groups have arisen; (2) Examine in detail three desert crane fly groups of Lunatipula, describing and illustrating all new and previously known species, determining the geographical distribution of each species and inferring each group's phylogenetic history; and (3) Use knowledge of the geographic ranges and evolutionary history of these three crane fly groups, as well as those previously published for other North American desert insects, to synthesize a general hypothesis regarding development and diversification of the North American desert insect fauna. The studies will utilize specimens already in museums as well as those secured on three collecting trips to the Southwest and northern Mexico.
