Another bee mimic

Flower gardens are in bloom up and down the street, so I took a stroll to see what insects I could find on the rich diversity of flowers available right now.  There should be lots of bees gathering nectar and pollen from those flowers, right?

robber fly-bumblebee mimic

robber fly-

Is this a bumblebee?  Hmm… doesn’t look quite right.


Well, let’s compare these two bumblebees on a dahlia with that “bee” above.

The bumblebee pretender has only one pair of wings, big bug eyes, no pollen baskets on those big hind legs, funny looking feet (not bee-like), and a big proboscis that sticks straight out from its head rather than straight down, like a bee’s would.  It looks like a bee, flies like a bee, even hums like a bee — but it’s a fly!  More specifically a robber fly, a predator of bees and other flying and crawling insects.

robber fly-bumblebee mimic

A closer look at this robber fly-bumblebee mimic nicely shows off his predatory apparatus.  Robber flies dart out and catch prey with their spiny legs, then ram their proboscis right into an unsuspecting insect, inject some salivary enzymes into the prey via the proboscis, and slurp back the digested material.

Laphria-Myrmecos blog-Alexander Wild

A bee-mimicking Robber Fly (Laphria species) attacks and consumes a honeybee. Photo by Alexander Wild.

There were only a couple of bees in the garden today — many fewer than I would have expected.  But there were lots of bee mimics, hoverflies, robber flies, and others.  Where are all the bees?  Do you see bees in your garden?  Look closely, what you’re seeing could be bee mimics.

A face only a mother could love…

Flies are not my favorite insects.  Something about them is icky, perhaps because I associate so many of them with biting, itching, buzzing, and being generally annoying.  But the fly I watched yesterday was truly impressive.  It was hover-flying between leaves, and I thought it was a bumblebee, but it had another fly snared between its legs.

It’s a robber fly, most likely one of the bumblee-mimicking genus Laphria, that specialize in grabbing flies, bees, even dragonflies and butterflies out of the air, immobilizing them with their big spiny feet and stabbing them in their thorax with the sharp, stout proboscis you can see sticking out from the “face”.

Their saliva apparently contains a neurotoxin that paralyzes the prey, as well as some digestive enzymes that turn the insect prey body to mush, which the robber fly then sucks back up its proboscis.

Robber flies are sit-and-wait predators (unlike many dragonfly species that search and capture their prey in flight).  With the aid of their big compound eyes, as well as three simple eyes set between the two big compound eyes, they detect prey flying by them and intersect their flight path to capture them.  Here he (or she) is sitting, gazing upward, and waiting for another meal to fly by.

Perhaps looking like a bumblebee makes them less threatening to potential prey in the area, but really all you have to see is that hairy “face” and lethal looking snout to know it’s not the innocuous buzzing bumbler.  For a nice closeup of their lovely face, check out this flickr photo.

A face like this, really only a mother could possibly love.