These bee flies are abundant in southeast Utah.

Bombyliidae is one of the largest families of Diptera, with over 5,000 valid species described worldwide. Their high diversity may be due to the parasitoid habit of the majority of their larvae. Adults feed on nectar and pollen, and are believed to be important pollinators of many plants, although few species have been studied in detail. Bee flies occur on all continents except Antarctica, however their highest diversities occur in semi-arid and arid environments (Hull, 1973).

The family includes a wide variety of morphological forms, such as the enormous Palirika marginicollis (Gray), with irridescent green-blue body scales recalling those found on the wings of a Morpho butterfly, and striking black and hyaline wings spanning 45 mm; and the tiny, delicate, humpbacked yellow and black species of Glabellula Bezzi with hyaline wings and a body length about 1 mm.