Chrysanthrax arenosus

Members of the genus Chrysanthrax, including C. cypris, are distinguished by distinct patches of black on the wings. Specific diagnostic features for C. arenosus are not documented in available sources.

Associated with areas supporting ground-nesting bees, including meadows and alluvial banks with abundant wildflowers.

Mexico and New Mexico, United States.

Active during spring when ground-nesting bees are provisioning nests.

Adults feed on nectar obtained using a long proboscis. Larvae are parasitoids; specific hosts for this species are not documented, though related species in the genus attack larvae of ground-dwelling beetles such as tiger beetles.

Females deposit eggs in or near burrows of ground-nesting hosts. Larvae enter host galleries and develop as parasitoids, consuming host provisions and then the host larva itself. Specific details for this species are not documented.

Adults hover at flowers and exhibit rapid, frenetic flight. Females have been observed following solitary bees back to their nests to locate oviposition sites.

Adults contribute to pollination through incidental pollen transport on their hairy bodies. Larvae function as parasitoids, potentially regulating populations of ground-nesting insects.

Adults may be mistaken for bees due to their hairy appearance and flower-visiting behavior, but they cannot sting. No significant economic impact documented.

• Chrysanthrax cyprisShares the genus and similar wing patterning with black patches, but specific differences from C. arenosus are not documented.
• Bombylius majorBoth are bee flies with long proboscises and similar pollination behavior, but Bombylius lacks the distinct wing markings of Chrysanthrax.
• Xenox tigrinusAnother bee fly parasitoid, but attacks carpenter bees rather than ground-nesting hosts and lacks the wing pattern of Chrysanthrax.

Adults are often mistaken for bees due to their hairy bodies, flower-visiting behavior, and common name 'bee fly.' They possess only one pair of wings ( Diptera), lack stingers, and are not closely related to Hymenoptera.

• bee fly
• parasitoid
• pollinator
• ground-nesting bee associate
• New Mexico
• Mexico

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Ground nesting bees beware of the bee fly: Bombyliidae — Bug of the Week
• Danger afoot for ground nesting bees: Look out for bee flies, Bombyliidae — Bug of the Week