Bee flies, belonging to the family Bombyliidae, are fascinating insects often mistaken for bees due to their fuzzy appearance and buzzing flight. These creatures are true flies, yet they effectively mimic the look and sound of bees, which helps them avoid predators. They navigate diverse environments, from gardens to open fields.
Identifying a Bee Fly
Distinguishing a bee fly from an actual bee involves observing several key physical characteristics. Bee flies typically possess stout, hairy bodies, often covered in dense, soft fur that can range in color from brown, black, or gray to vibrant yellows. A prominent feature is their long, slender proboscis, or mouthpart, which extends forward from their head and is used for feeding on nectar. This proboscis is often held straight and does not retract, sometimes leading to confusion with a stinger.
A clear way to differentiate them from bees is by examining their wings. Bees have two pairs of wings, which they often fold close to their body when at rest. In contrast, bee flies, like all true flies, possess only a single pair of wings, often held out and back at a characteristic “swept back” or “V” angle when at rest.
Additionally, bee flies typically have short, stubby antennae, unlike the longer, more segmented antennae of bees. Their large, compound eyes often cover a significant portion of their head, sometimes appearing to nearly touch. Unlike bees and wasps, which often have a distinct, narrow waist, bee flies have a more compact body where the thorax and abdomen fit closely together without a pronounced constriction.
Bee Fly Behavior and Role
Bee flies exhibit a distinctive hovering flight pattern, allowing them to remain suspended in mid-air, much like hummingbirds. This agility enables them to feed on nectar and pollen from flowers, often without fully landing, while buzzing audibly. As adults, their diet primarily consists of nectar and pollen, which they collect using their long proboscis. This feeding behavior makes them effective pollinators, contributing to the reproduction of various flowering plants, including those with deep floral tubes. While some bee flies may obtain nectar without contacting pollen, their fuzzy bodies still facilitate pollen transfer as they move between blossoms.
The larval stage of bee flies, however, presents a different ecological role. Most bee fly larvae are parasitoids, meaning they develop by feeding on the eggs or larvae of other insects, eventually killing their host. Female bee flies employ a unique method for laying eggs, often hovering over the burrows or nests of host insects, such as solitary bees, wasps, beetles, or even grasshoppers, and flicking their eggs into or near the entrance. Once hatched, the bee fly larvae enter the host’s nest, consuming the host’s larvae or their stored food. This parasitic lifestyle contributes to natural pest control within ecosystems.
Are Bee Flies Dangerous?
Despite their bee-like appearance, which can sometimes be intimidating due to their long proboscis resembling a stinger, bee flies are entirely harmless to humans. They do not possess a stinger and are incapable of biting or stinging people or pets. Their mimicry of more dangerous insects serves as a defense mechanism to deter potential predators. This visual deception allows them to avoid being targeted, despite their peaceful nature. Bee flies also do not transmit diseases, and their presence is beneficial as they contribute to pollination and help regulate populations of other insects through their larval parasitism.