Western Horse Fly (Tabanus punctifer)

Found this specimen in the parking lot at Marketplace in Friday Harbor yesterday. Glad I didn’t turn into the “grabber” I can sometimes be and instead used a box to scoop up my big find. Probably if you were watching me, you’d have been scratching your head wondering WHY is this woman going through her grocery sacks and opening a snack box of tuna?  That box made an excellent fly “trap!”


Big is an understatement! This is the LARGEST fly I’ve collected on the island.  It measures over 1 inch long or more than 2 cm.  The Western Horse Fly (Tabanus punctifer) can bite through your clothing, although it is the female that needs a blood meal (males feed on nectar and pollen). The adult female lays egg masses (over 300 per mass) on vegetation along ponds and lakes. When the eggs hatch, the larvae develop in the water and here is what I read about them from my sources at Bugguide.com…

“These larvae are aquatic. They have mouthparts that are identical to those of rattlesnakes in structure. A pair of hollow fangs that are connected to a poison/anaesthecic salivary gland further back in the body. These mandibles can easily break through human skin and inject the immobilizing contents of the salivary glands. Normally used to paralyse, and perhaps digest, prey. They are capable of quickly immobilizing/killing animals as large as frogs. They are strictly carnivores and eat ‘meat’.”

I guess this means that the toe-biters aren’t the only ones you should avoid when you go for that swim!

If you care to read more, I suggest this excellent informative guide I found online.   It is a 1921 publication from Sanitary Entomology:  The Entomology of Disease, Hygiene and Sanitation ~ https://play.google.com/books/reader?id=eIQoAAAAYAAJ&printsec=frontcover&pg=GBS.PA237Sanitary Entomology



Greater Bee Fly (Bombylius major)

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!


Greater Bee Fly (Bombylius major)

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!


Greater Bee Fly


Mosquito-like legs of Greater Bee Fly

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:


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






Winter Crane Fly

It snowed on San Juan Island this week.  We were forecast to have LOTS of rain yesterday, but instead we got more snow.   So much snow that this former Texas gal just had to get out and experience the magic of our wooded, winter wonderland.


I got my coat, hat, and boots on, grabbed my iPhone and a pair of gloves, wrapped a scarf around my neck and set off to walk down our lonely country road.

Hoping to photograph some of our year-round feathered residents, I had my camera phone in hand.  It was really cold outside and yet I couldn’t use the touchscreen wearing my glove.  Off it came.  I could sacrifice cold fingers if I could get a shot of one of the woodpeckers or maybe a Varied Thrush.

Heading down the driveway, I noted the way the limbs of the cedars and firs bowed down under the weight of the snow.  Beneath them, little birds scurried, scratching about in the damp humus or flitting about on lower branches, enjoying a protected shelter from the cold.   It took only a moment to spy a  Dark-eyed Junco near the house on a leafless limb of our cherry tree and the Varied Thrush perched just above my head…perhaps waiting to see if I brought more seed out for them.


Dark-eyed Junco (Junco hyemalis)



Varied Thrush


A bit further down the driveway, I smiled when I saw our little carved bear.  He’s not long for this world.  The carpenter ants and the damp weather are slowly turning him into sawdust….but he rallied under his snow blanket today even though his little black nose was about all you could see.


Snow Bear


Wait…isn’t this post about a Winter Crane Fly?  Well, I’m getting to that part.   I certainly wasn’t anticipating seeing any invertebrates out on a day like this.  While I’ve heard of snow fleas (not really fleas, but tiny invertebrates known as collembolans or springtails) or snow scorpionflies (Boreus spp.) found in winter in our forested area, I’ve yet to see them.   It’s really a mystery how so many of these tiny creatures survive the extreme temperatures, but that’s also what makes them so interesting.

I came across the first of about ten of these tiny, winged “cranes” before I’d made it far down the road.


Winter “Crane”

We live in a somewhat densely forested area.  Not many houses or development to interfere with the important ecological processes going on in the natural world.  At first, it appeared to be a mosquito.  Go figure. Somehow they thrive in Alaska, Minnesota, even the Arctic…in spite of frigid temperatures!

Looking closer, I speculated it was in the family Tipulidae, a common, but harmless, mosquito-looking, awkward flying, long-legged fly!  I had to do some research to figure it out.  The Tipulids are a genus in the insect order (Diptera) and commonly called “Crane Flies.”  However, a bit of digging into the literature proved I was close to my ID of this creature, but not quite there.

What I discovered is that this is indeed a Crane Fly, but not a Tipulid.  It’s a WINTER Crane Fly in the genus Trichoceridae.  They are found flying on “warm sunny afternoons in fall, winter, and spring in the contiguous U.S., including Alaska and Canada” (Pratt 2003).  In his study, Pratt (2003) observed specimens “swarming above or on the snow in temperatures between 0℃ and 10℃.”  Maybe “warm” is subjective here!

This tiny Winter Crane Fly is very similar to the Tipulids or True Crane Flies with its long slender legs, but it differs in classification because the Winter Crane Fly has three ocelli (https://www.amentsoc.org/insects/glossary/terms/ocelli)  or simple eyes that act as light sensors and are found on top of the head.  The larvae of Trichocerid flies develop in the moist humus and decay of the forest floor and undoubtedly play some ecological role in this environment i.e. in decomposition or nutrient recycling.  At a minimum, they are a nice protein-rich winter meal supplement for the little birds I’ve seen on my walk today.

While I’m not certain of the exact species, in the article by Pratt (2003), adults of one species, Paracladura trichopera, are found flying even in winter in British Columbia, Washington, Oregon, and California.   Perhaps it will suffice to say that I was intrigued at the cold-hardiness of such a tiny creature.  And I DO like the name, Winter Crane Fly!


Winter Crane Fly Trichocerid spp.



1. The winter crane flies of North America north of Mexico (Diptera: Trichoceridae)
Pratt H.D. 2003. Proc. Entomol. Soc. Wash. 105: 901-914.  http://www.biodiversitylibrary.org/page/16212448




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