Most Monroe Countians have an ongoing battle with carpenter bees. Although they are hard-working pollinators, they draw our ire when they lay their eggs in holes excavated in bare wood. People employ a number of techniques to thwart the bees, such as swatting them out of the air, spraying areas where they are boring holes with citrus sprays, playing loud music near their nests, and spraying their nesting cavities with insecticides.
Meanwhile, many homeowners plagued with carpenter bees do not realize they have a wild ally that works diligently throughout the warm months to control carpenter bees. Mother Nature’s carpenter bee control agent is an insect known as the tiger bee fly.
The insect’s name and menacing appearance would lead you to believe this is one critter you need to avoid. It is one of the largest flies you have probably ever seen. A tiger bee fly can measure anywhere from 0.75-1.75” long. It has a long proboscis that gives the insect the appearance of a really big mosquito. Fortunately, the long, slender proboscis is not capable of drawing blood from man or beast.
Its body is black and fuzzy, suggesting it is a large bee. The fly’s long, tapered, clear wings are decorated with an intricate black design. The markings located along the trailing edge of the wing look somewhat like tiger stripes. Its huge eyes look much like giant versions of the eyes of a housefly. The insect’s black abdomen is marked with two white spots.
Unfortunately, many tiger bee flies are killed by folks that mistake them for a stinging or biting insect, such as a horsefly. In truth, the tiger bee fly is a harmless and highly beneficial insect.
Remarkably, in spite of the tiger bee fly’s ferocious appearance, it is a native pollinator. The fearsome proboscis is actually designed to sip nectar from flowers.
In addition to pollinating plants, the tiger bee fly’s bizarre breeding habits should endear itself to all of us. After mating, the female actively hunts carpenter bee nest sites. As such, they are often seen hovering near carpenter bee nests. Once the female tiger bee fly locates a nest containing carpenter bee eggs, she lays her eggs alongside the eggs left by the carpenter bee.
These larvae are parasites. Therefore, when they hatch the tiger bee fly larvae quickly seek out the carpenter bee larvae that occupy the same nest. Once located, tiger bee fly larvae begin eating the newly-hatched carpenter bees alive. Although this activity is gruesome, it ensures the carpenter bee larvae never live long enough to leave their nest. Who would have ever thought something like this might be going on in a carpenter bee nesting cavity?
I suspect even if you have never seen tiger bee flies, they are probably living in your backyard. My wife and I have been living in our home for more than 40 years and had never seen one well enough to make a positive identification. That changed a week ago when my wife spotted one basking in the sun on the side of the house. Since then I have seen a pair mating.
Once people become familiar with the tiger bee fly, it often becomes one of their favorite insects. In fact, this popularity has prompted retailers to offer a number of tiger bee fly items such as shower curtains, sheets, comforters, mugs and clothing.
Tiger bee flies range across the entire state. They are most abundant in locales where there is an abundance of nectar-bearing plants and suitable nest sites. Like many beneficial insects, they cannot survive in places sprayed with pesticides.
If you are looking for an ally to help control carpenter bee damage to your home and property, it makes sense to encourage tiger bee flies to take up residence in your backyard. One of the simplest ways to begin accomplishing this goal is to stock your yard of a variety of nectar-bearing plants that bloom throughout as much of the year as possible. Reduce or eliminate the use of insecticides. In addition, don’t kill that large, scary looking insect that appears poised to sink its long proboscis into your arm--it just might be a tiger bee fly.
Terry Johnson is retired Program Manager of the Georgia Nongame-Endangered Wildlife Program. He has written the informative column ‘Monroe Outdoors’ for the Reporter for many years. His book, “A Journey to Discovery,” is available at The Reporter. Email him at email@example.com.