To Bee or Not to Bee

Mimicry:  The resemblance of one organism to another for concealment and protection.

This large drone fly looks so much like male European honeybees that many predators often give this fly a pass.

I discovered this drone fly in late August dining on the onion flowers in my garden. At first I thought it was a large bee, but soon realized my mistake. After checking several sources I found some ways to tell the two apart.

  • First, count the wings.

Two wings, no sting. (You’ve found a drone fly.)
Four wings, ouch. (If you mess with a queen or a worker bee you may get stung.)

Drone fly

  • Second, does it hover in the air?

Drone flies are a type of hoverfly and — like the name suggests — they can hover like a helicopter. Honeybees can’t do that.

  • Third, check the antennae.

Honeybees have longish antennae, with an elbow-like kink in each. Drone flies have little stubby knobs.

  • Finally, look at its back.

Can you see the big black “H” just past the mid-section? You’ve got yourself a drone fly. Yup, I know honeybee starts with an “H”. Think helicopter or hoverfly instead. 🙂

Drone Fly

Drone flies are the Jekyll and Hyde of the fly world. Adults are easy on the eyes. Larvae, are, well, um, icky to say the least. Some might say gross.

Rat-tailed maggots live in manure lagoons and similar places with high levels of “organic matter” (i.e. feces). The long “tail” is actually a breathing tube so the maggot can feed underwater without returning to the surface for air.

The University of Florida’s Featured Creatures website has excellent photos comparing honeybees and drone flies — and several of the rat-tailed maggots. You might also want to check out the description of “accidental myiasis”. That should keep you up at night.


Drone fly   Eristalis tenax

 

How the Bumblebee Lost Her Buzz

I spied a very quiet bumblebee sitting near one of the lupines yesterday. Odd behaviour for midday.

I looked closer. Ooops. The bumblebee had stumbled into the clutches of a large goldenrod crab spider.

Caught

Crab spiders are ambush predators. They wait for insects to visit flowers in search of pollen and honey.

They blend in well which makes them successful hunters. Using pigments in their body they can even change colour, from white (often with pink stripes or blotches) to yellow and back again. According to the Encyclopedia of Life it takes 10-25 days to turn from white to yellow but only about 6 days to turn from yellow to white.

So: Bumblebee arrives. Spider grabs it with her outstretched legs. Injects venom through her fangs. Paralyzes bumblebee.

Predator and prey

Once the prey is subdued the spider injects digestive enzymes into (or onto) the victim’s body, liquefying the insides. Then it slurps up the liquid. Nothing like a high-powered  protein shake for lunch.

Death among the flowers

How long did it take from start to finish? Hard to say. When I first discovered the bumblebee she was pointing head-first into the flower. When I checked again about 30 minutes later the spider had manoeuvred the bee around so that its head was pointing more to the front. Was this so she could better access the body fluids?

Manoeuvring her prey

Later still I discovered that the spider had finished her meal. I checked for bumblebee remains — in the flower stalk, on the ground, among the leaves. Nothing. Where did it go? A mystery.

I checked the lupine again today. The crab spider was still there. A moment later I stood transfixed as a fat bumblebee landed on the flowers, just petals away from the spider-in-hiding. Would she catch this one too?

Too close for comfort

Luckily for the bee she buzzed off to another stalk. As for the spider? She crawled out in full view, stretching out in the sun, legs poised, waiting …

The watchful waiter


Goldenrod crab spider   Misumena vatia
Bumblebee   Bombus spp.