Bee Fly: All You Need to Know for a Buzzing Encounter

Bee flies are fascinating insects often mistaken for bees due to their fluffy appearance and hovering flight pattern.

These creatures, however, are members of the Bombyliidae family of true flies and do not possess the ability to sting or bite.

Found in various regions such as North America, Europe, and Asia, many bee flies are expert bee mimics and have interesting features worth exploring.

bee fly
Bee Fly: Lepidophora lutea

These furry insects can be easily spotted in the spring, flying just above the ground.

They have a distinct long proboscis, which serves as a straw-like mouth tube for sipping nectar from flowers.

While they don’t sting, bee flies play a vital role as pollinators and contribute to plant biodiversity.

Bee Fly Basics

Identification

Bee flies are insects that resemble bees but belong to the Diptera family of flies.

They belong to the family Bombyliidae, which is part of the order Diptera.

They can be distinguished from true bees by observing their number of wings:

  • Bee flies: 2 wings
  • True bees: 4 wings

Diptera is a large and diverse group of insects that includes flies, mosquitoes, and midges. Some characteristics of Diptera insects include:

  • Single pair of wings
  • Mouthparts adapted for sucking or piercing
  • Simple metamorphosis (egg, larva, pupa, adult)

Bee Fly

Hairy Appearance

Many bee flies exhibit a hairy appearance, which contributes to their bee-like resemblance. This hairy body helps them to:

  • Mimic bees and deter predators
  • Provide insulation in cooler environments
  • Aid in pollen collection for their larvae

Dark-Edged Bee-Fly

The dark-edged bee-fly (Bombylius major) is a well-known species of bee fly. Some features of this species include:

  • Dark, smoky wing edges
  • Proboscis for feeding on nectar
  • Distribution across North America and Europe

Overall, bee flies are fascinating insects that closely resemble bees but possess unique characteristics that set them apart.

By understanding their identification, diptera family, hairy appearance, and the dark-edged bee-fly species, one can more easily recognize and appreciate these intriguing creatures.

Tiger Bee Fly

The Tiger Bee Fly is a striking insect known for its distinctive appearance and intriguing behaviors.

A member of the Bombyliidae family, this fly is characterized by its large size, black body, and patterned wings that resemble those of a tiger, hence its name.

Unlike bees, the Tiger Bee Fly does not sting or collect pollen.

Instead, it is known for its parasitic reproductive behavior. Female Tiger Bee Flies lay their eggs near the nests of solitary bees.

Upon hatching, the larvae enter the bee nests, where they consume the bee larvae.

Despite their parasitic nature towards bees, Tiger Bee Flies play a role in the ecosystem’s balance, showcasing the intricate web of interactions in nature.

Biology and Behavior

Feeding Habits

Bee flies are known for their unique feeding habits. They primarily feed on nectar and pollen from flowers using their long proboscis, a specialized mouthpart that acts like a tongue.

Some examples of flowers they feed on include:

  • Daisies
  • Buttercups
  • Lavender

Foraging Patterns

Bee flies display distinct foraging patterns. They are typically most active during the day when flowers are producing nectar.

Factors that influence their foraging include:

  • Temperature: They prefer warmer temperatures to forage
  • Flower availability: They are selective and forage on specific flower species

Bee flies display a hovering behavior, which enables them to conserve energy while they forage.

Here’s a comparison between bee flies and bees on various paramters.

 Bee FliesBees
ForagingDaytimeDaytime
Flight StyleHoveringDirect
DietNectar, PollenNectar, pollen

Bee-Like Robber Fly: Laphria thoracica

Reproduction and Lifecycle

The reproduction and lifecycle of bee flies are fascinating:

  1. Larva: Female bee flies deposit their eggs near the entrance of a host insect’s nest. Once the larvae hatch, they find their way into the nest and consume the host larvae or eggs.
  2. Pupa: After feeding on the host, bee fly larvae will transform into pupae and remain dormant until they emerge as adults.
  3. Adult: Adult bee flies have short lifespans, usually lasting only a few weeks in the spring.

Some features of bee fly reproduction:

  • Use of an ovipositor to deposit eggs
  • Parasitic behavior toward host species
  • Timing of reproduction to match host availability

Bee flies’ parasitic behavior can have both pros and cons in their ecosystem:

Pros:

  • Helps control host insect populations
  • Provides a niche role in the ecosystem

Cons:

  • Can harm host species populations
  • May decrease biodiversity in certain areas

Bee Fly and Pollination

Role in Ecosystem

Bee flies play a crucial role as pollinators for various flowering plants.

They help in carrying pollen grains between flowers, contributing significantly to seed and fruit production.

Native Pollinators

As part of the native pollinator group, bee flies differ from other common pollinating insects such as bees, wasps, and butterflies.

Some characteristics of bee flies that set them apart from other pollinators include:

  • Possessing only one pair of wings
  • Being extremely hairy
  • Mimicking bees and wasps

These native pollinators are essential as they help maintain the natural balance of ecosystems, supporting the growth of native plants, and providing food variety to wildlife.

Bee Fly

Pollinator Diversity

Pollinator diversity is crucial for healthy gardens and ecosystems.

Various pollinators specialize in unique types of flowers, increasing the chances for successful pollination.

Here’s a comparison table of some common pollinators:

PollinatorSpecialization
Bee FlyGeneralist, visits a variety of flowers
BeesFlowering plants, some species-specific
WaspsPredatory insects, nectar foraging
ButterfliesLong-tubed flowers with nectar
MothsNight-blooming flowers
BatsLarge, night-blooming flowers
BeetlesFruit and flower-producing plants
Birds (Hummingbirds)Tubular and brightly colored flowers

Welcoming a diverse range of pollinators such as bee flies, bees, wasps, and others into gardens will ensure efficient pollination, vibrant flowers, and increased fruit yields.

Bee Fly Interactions with Bees

Mimicry Camouflage

Bee flies are known for their remarkable mimicry camouflage. These insects have evolved to look strikingly similar to bees, specifically in terms of:

  • Body shape and fuzziness
  • Coloration and patterns
  • Wing structure

This camouflage allows them to blend in seamlessly with bee colonies and flowers where bees gather pollen and nectar.

It serves as a defense mechanism, as predators may be less likely to attack them due to the fear of being stung.

Bee Colony Impact

Bee flies can have both positive and negative impacts on bee colonies.

On the one hand, they can help with pollination as they visit flowers while searching for nectar.

Bee Fly

On the other hand, bee flies can pose a threat to bees, especially if they infiltrate a hive.

Certain species of bee flies are known to lay their eggs near the hive entrance, which can harm developing bees.

Bee Flies vs Bees

While bee flies and bees may appear similar, they have some key differences when it comes to their stingers.

First, bee flies don’t have stingers, so they are harmless to humans. Second, the abdomen of a bee fly is more pointed and flexible, while a bee’s abdomen is less flexible and contains the stinger.

Lastly, bees use pheromones for communication and to protect their colony, while bee flies don’t have this ability.

 Bee FliesBees
StingNoYes
AbdomenPointed and flexibleLess flexible, stinger-equipped
PheromonesDon’t use pheromonesUse pheromones for communication

Temporal Variations in Bee Flies

Crepuscular Bees

Crepuscular bees are active during twilight hours, around dawn and dusk. They have adapted to forage when the light is low, which can provide some advantages, such as avoiding predators.

  • Examples: Indian Carpenter Bee, Central American Sweat Bee

Diurnal Bees

Diurnal bees are most active during daytime hours and rely on sunlight for navigation and foraging. They have excellent vision which allows them to locate flowers efficiently.

  • Examples: Honey bees, Bumble bees

Nocturnal Bees

Nocturnal bees can fly at night, thanks to their limited night vision. However, they are not as common as diurnal and crepuscular bees, and nocturnal bee species are relatively rare.

  • Key feature: Limited night vision

Comparison Table

 Crepuscular BeesDiurnal BeesNocturnal Bees
TimeTwilight hours (dawn and dusk)DaytimeNighttime
VisionAdapted for low lightExcellentLimited
AdvantagesAvoiding predatorsEfficientRare
ExamplesIndian Carpenter Bee, Central American Sweat BeeHoney bees, Bumble bees(few species)

Bee Fly

Bee Flies and Human Interaction

Allergic Reactions

Bee flies, while resembling bees, do not sting and thus do not cause any serious allergic reactions.

However, some individuals might be allergic to their hair or other body parts. Examples of symptoms include:

  • Itchy skin
  • Redness or mild swelling

Protective Gear

Because bee flies are not aggressive and do not sting, wearing protective gear is generally not necessary.

However, if you’re tending to your garden, fields, or parks, and are concerned about other insects such as bees or wasps, a few protective items include:

  • Insect repellent
  • Long-sleeved shirts and pants
  • Hat with a netting

Garden Benefits

Bee flies are considered beneficial to gardens because they help:

  • Pollinate plants: Like bees and hoverflies, they transfer pollen between flowers, aiding in plant reproduction.
  • Control pests: Bee fly larvae feed on the larvae of other insects, keeping the insect population in check. For example, primrose moth caterpillars.

Distribution and Habitat

Geographical Spread

Bee flies, belonging to the Villa genus, are commonly found in a variety of environments, such as fields, parks, and gardens 1.

Their distribution is extensive, encompassing diverse geographical locations which include:

  • North America
  • Europe
  • Asia

Bee Fly

Adaptation to Temperature

Bee flies have developed impressive adaptability to varying temperatures, allowing them to thrive in diverse habitats.

Noteworthy temperature-related traits include:

  • Cold tolerance: Bee flies can withstand colder environments, thanks to their furry bodies.
  • Heat resistance: Despite their preferred habitats in fields, parks and gardens, they can persist in warmer regions by seeking out shaded areas, like underneath primrose plants.

Conclusion

In summary, bee flies, members of the Bombyliidae family, are intriguing insects that often get mistaken for bees due to their fluffy appearance.

Despite their bee-like demeanor, they lack the ability to sting or bite.

These creatures are prevalent across North America, Europe, and Asia, and play a pivotal role as pollinators, enhancing plant biodiversity.

Their unique features include a long proboscis for sipping nectar and a distinct hovering flight pattern.

Additionally, bee flies exhibit a fascinating reproductive cycle, where their larvae parasitize other insect nests.

Understanding the differences between bee flies and true bees, such as wing count and behavior, helps in appreciating their unique role in the ecosystem.

Footnotes

  1. US Forest Service

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about bee flies. Scroll down to have a look at some of them.

Letter 1 – Bomber Fly

Subject: Bee or Moth?
Location: Lassen Volcanic Park, California
August 3, 2012 6:27 am
While hiking on Bumpass trail in Lassen Park California, we stumbled on this little critter acting like a hummingbird.

It looked like a bee, but a passerby mentioned that it may be a moth.
I’m stumped. Can you help me identify it?
Thanks So Much,
Rob
Signature: Rob Fernandes

Bomber Fly

Hi Rob,
This is neither a bee nor a moth.  We thought it might be a Bee Fly in the family Bombyliidae, but we did not recognize the markings on the abdomen. 

We turned to BugGuide where we quickly identified this impressive creature as a Bomber Fly, Heterostylum robustum, indeed one of the Bee Flies. 

BugGuide identifies it as a:  “Large Bee-fly with long proboscis and strong pattern on rear of abdomen.”  This is a new species for our archive.

Daniel,
Thanks so much for you help identifying the Bomber Fly! I’m glad I could help expand your archive as well. Here is one other pic of the fly from a different angle showing better leg detail.
Cheers,
Rob

Bomber Fly

Thanks for sending an additional photo Rob.  The proboscis is also nicely visible in the new photo.

Authors

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  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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