The horse flies of Arizona. I. Introduction and zoogeography (Diptera: Tabanidae)

In this first part of a series [cf. next abstract], the zoogeography of the Tabanid fauna of the topographically very diverse state of Arizona is discussed. It consists of 43 known species in 11 genera and includes elements of three different groups. One group moved into the isolated mountain ranges and grasslands of south-eastern Arizona, from the Mexican Highlands and Central America, with some species penetrating the central and north-eastern parts of the State. A second group characteristic of the Rocky Mountains, entered Arizona mainly through western New Mexico. A third from the arid regions of north-western Mexico and south-eastern California penetrated the more arid parts of Arizona in the south and west. Many species in south-eastern Arizona are now isolated from their congeners in northern Mexico by semi-arid desert due to relatively recent climatic and associated vegetational changes in southern Arizona and northern Sonora, Mexico.