Bombyliidae

The Bombyliidae are a family of flies, commonly known as bee flies. Some are colloquially known as bomber flies. Adults generally feed on nectar and pollen, some being important pollinators. Larvae are mostly parasitoids of other insects. The Bombyliidae are a large family of flies comprising hundreds of genera, but the life cycles of most species are known poorly, or not at all. They range in size from very small (2 mm in length) to very large for flies (wingspan of some 40 mm). When at rest, many species hold their wings at a characteristic “swept back” angle. Adults generally feed on nectar and pollen, some being important pollinators, often with spectacularly long proboscises adapted to plants with very long, narrow floral tubes. Unlike butterflies, bee flies hold their proboscis straight, and cannot retract it. Many Bombyliidae superficially resemble bees and accordingly the prevalent common name for a member of the family is bee fly. The larval stages are predators or parasitoids of the eggs and larvae of other insects. The adult females usually deposit eggs in the vicinity of possible hosts, quite often in the burrows of beetles or wasps/solitary bees. Although insect parasitoids usually are fairly host-specific, often highly host-specific, some Bombyliidae are opportunistic and will attack a variety of hosts. Read more on Wikipedia.