The Robber Flies of Texas(Diptera, Asilidae)1

Abstract

Texas not only has the distinction of being the largest state in the Union, but also appears to be proportionately endowed in other respects. There is a tremendous variety of both flora and fauna. The Dipterous family Asilidae, with which this paper deals, is represented to an extent unparalleled either in species or in individuals by any other region in the country. The list following, which must be considered as only preliminary, comprises 161 species. If contrasted with the author's recent list for Ohio of 65 species, an idea of the wealth of the Texas asilid fauna may be gained. In addition, Texas may boast of some of the largest species of these predacious flies occurring in North America. Microstylum morosum (Pl. 1, Fig. 9), (No. 30 in the list), originally described from Dallas, reaches a length of 50 mm.; Promachus giganteus (Pl. 1, Fig. 2), (No. 111) from the western part of the state, may exceed a length of 47 mm.; while in actual bulk there are probably no species in North America greater than the large bumblebeelike Bombomima lata. (No. 88), the type locality of which is Galveston, or the huge MalloPhora belzebul (No. 100), from the Uvalde region. The latter species also occurs in Mexico and Brazil.