by Pat Jaquith
pat@westvalleynaturalists.org

As I write this on a rainy day in March, my mind is drawn to thoughts of spring, perhaps because just yesterday I was walking partly in mud, partly on ice, torn between the need for rubber boots or ice cleats. In a similar vein, in summer as I observe flowers and the insects that are drawn to them, I wonder whether I should beware of the stinger or relax and admire the industrious work of the flying creatures. In this article, I’ll share some helpful tips I have learned from researching that question.

BEES

While there are bees of many descriptions – from the totally furry-looking Bumblebees; the metallic green-bodied Sweat bees; Honeybees with heart-shaped heads and furry-rimmed eyes; big and little, all bees have some characteristics that help us recognize their family traits.

• Bees have four wings; well, if they are dead, you might be able to count them, but that’s not a very easy characteristic to look for.
• Bees carry their wings close to their bodies when at rest. Not always easy to determine, given their quick movements, size, and the observer’s possible anxiety, but easier than counting.
• Bees have segmented bodies: a head, thorax, and abdomen.
• Their antennae are segmented and bent.
• They are “hairy” and designed to carry pollen somewhere on their body.
• Females have a stinger. I can’t recommend checking for this characteristic!

BEE-FLIES OR BEE MIMICS

Members of the species Bombylius (Bee-fly) have a fixed proboscis that extends in front of them for feeding on nectar. They are important as pollinators because they feed on many types of flowers. They are parasitic bee mimics. Because they look so much like a bee, they can get near the bee or wasp nest where the female lays her eggs near the entrance. After the larvae develop, they enter the nest, feed on stored food and parasitize a larva in the nest. When that development stage is complete. they form a pupa and overwinter in the nest.

Bee-fly Anastoechus barbatus Common name Bearded Bee Fly

FLIES

Flies are often mistaken for bees. A few characteristics help to classify them as flies:

• They have two wings. It is easier to count fly wings because they usually hold them at an angle when they are at rest.
• Flies are ‘bristly’ – spiky is a good descriptor for their hair
• Their antennae are short, looking a bit snout-like on their faces
• They have big eyes that often almost meet at the top of their heads
• Hover flies, as the one pictured above, remind me of modern drones: they zip around over the area, hovering, but seem not to land. But when captured in a photograph, it’s easier to see some physical characteristics that help to separate them from their “bee-ish” first impressions.
• Tachinid fly species are numerous, and they come in different sizes and descriptions. However, the bristly bodies and wings held in a V-formation can be seen with only a casual look. Then, knowing they don’t sting, one can relax and get more views when the short antennae and big eyes help add to the “fly” identification.

Robber flies are big (more than an inch long, often) and intimidating-looking. Robber flies belong to the fly family Asilidae. They prey on all sorts of other insects, often larger than themselves. They hunt by choosing a perch or hiding spot and grab a meal on the fly. One characteristic of Robber flies is their fixed proboscis – it doesn’t retract. They stab it into their prey, inject chemicals that stun, then dissolve the interior which they consume. The proboscis is visible in #1 which was floating in a container of water.

I consulted a great number of websites in studying about bee and fly identification. https://urbanipm.montana.edu/resources/mt-bee-id.html is a good resource for information about bees that we see here in the West Valley. You might also consult the articles on our website that catalog some of the bee species we encounter around here:

• A Very Special Bumblebee
• A Western Bumblebee
• A Season of Bees