Bugging You From San Juan Island

Thankfully the sun was out for a bit yesterday afternoon.  The gray skies and temperatures hovering in the mid 40’s make for a long springtime in the Pacific Northwest.  Fortunately, the rain brings spring blooms for the pollinators that are emerging and I was thrilled to finally get a (relatively)  clear shot of the Greater Bee Fly as it visited one of the pansies in my hanging basket.   For those who may have never attempted to photograph a bee fly, all I can say is that they are incredibly fast and extremely camera shy!

The bee fly is an early pollinator and it is not a bee, although it really looks like one with all of its fuzzy hair.  The Bee Fly is actually a FLY in the insect order Diptera.  This means it has only one pair of wings (actual bees in the order Hymenoptera have TWO pairs of wings!), stubby antennae, and very large eyes.  This photo I took capturing the back of the bee fly shows how closely their hind legs resemble the legs of other diptera, like mosquitoes and crane flies.  Two other amazing features of the Bee Fly are its incredibly long proboscis or “tongue,” enabling it to reach deep into flowers with tubular shapes (like those on Red-Flowering Currant ~ Ribes sanguinium) and its ability to hover mid-air and zoom away, much like the aerobatic maneuvers of a hummingbird!

Bee Fly adults emerge and fly from late March through May.   Their preferred habitat is along the edges of woodlands where they fly about seeking nectar from flowers of herbaceous plants (like my pansies!).   If you take a walk about on a sunny day, you may find them visiting emerging wildflowers… like the ones in this great book ~ https://www.amazon.com/Wildflowers-Pacific-Northwest-Timber-Press/dp/0881927457 .  I have also seen them visiting flowers on shrubs we have in the Pacific Northwest, including Salmonberry (Rubus spectabilis) and Thimbleberry (Rubus parviflorus).

Although a pollinator, the “dark” side of bee fly livelihoods is their nature of taking advantage of other pollinators.  While bee fly adults are happy to fly around taking sips of nectar, they aren’t very interested in caring for their brood or offspring.  Instead, the bee fly female will seek out ground nests of solitary bees like those in the Genus Andrenidae (mining bees), and also those in Colletidae (plasterer bees) and Halictidae (sweat bees).  The bee fly can hover over the open nest cavities of these bees and drop eggs down into them or nearby.  Bee fly larvae hatch and compete with the bee larvae for the pollen provisioned inside these nests.  As they grow, the bee fly larvae become carnivorous and eat the developing bee larvae.   If you would like to read more about this process, check out this really informative article by Louise Kulzer here ~ https://crawford.tardigrade.net/bugs/BugofMonth19.html

 

Further reading:

https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/bee_flies.shtml

http://drawwing.org/insect/bombylius-major-wing-0.  (Wing venation of Bombylius major)

https://bugguide.net/node/view/14997