Identification
Courtesy Jessica Womack.
Like many other insect groups, accurate identification of bumblebee species can be a little tricky. Within a species, individual color patterns can vary. Male bumblebees often have color patterns that differ markedly from those of females (queens, workers). Don’t let that intimidate you, however.
Nine bumblebee species are currently known to occur in Texas (see Texas Bumblebees). That is not an overwhelming number to familiarize yourself with. Just think of all the species bird-watchers have to learn! With some patience and study, you should be able to familiarize yourself with the bumblebees that occur in the state.
Fortunately, when collecting nectar or pollen, bumblebees can be easily observed (use binoculars if you want) and are relatively tolerant of humans. But remember, bumblebees (at least females) can deliver a relatively painful sting. Unlike the European honeybee, they can also sting multiple times. I have found bumblebees that are away from their nests, foraging on flowers, to be very placid and often oblivious to our presence (if left unmolested). A bumblebee trapped in a butterfly net is a whole other matter. Never disturb a bumblebee colony if you discover their nest. They will defend it.
Bumble Anatomy
All bumblebees are relatively large, fuzzy insects. Their body is divided into three segments, the head, thorax, and abdomen. The abdomen of queens and workers is composed of six segments , whereas the abdomen of male bumblebees is composed of seven segments.
Dense hairs, in varying combinations of black and yellow, cover most of their body. When attempting to identify a bumblebee, the features you will want to concentrate on most will be the pattern of black and yellow on the thorax and abdomen.
Bumblebee (left) and eastern carpenter bee (right). Note hairy abdomen of former and shiny, smooth abdomen of latter. Courtesy Jessica Womack.
Mistaken Identities
A number of insects can be confused with bumblebees, chief among these is the eastern carpenter bee (Xylocopa virginiana). This is a large, native bee with the same general shape as a bumblebee. It also has yellow hairs on its thorax. A major distinguishing feature between the two is the carpenter bee’s abdomen. Carpenter bees have shiny, black abdomens with very few hairs, while bumblebees have furry abdomens. Other insects that could be mistaken for a bumblebee include a day-flying moth, the snowberry clearwing (Hemaris diffinis) and several species of robberfly (Laphria and Mallophora species). Unlike bumblebees which land and crawl over flowers to forage, the snowberry clearwing hovers in front of flowers to feed. The predatory robberflies that mimic bumblebees do not feed from flowers but rather prey on other insects, including bumblebees. Robberflies typically perch on vegetation, flying out as potential prey passes by.
I.D. Basics and Tools
From spring into to mid-summer, female bumblebees will be the most commonly encuntered sex. As a result, identification is simplified at this time of year with the absence of contrastingly patterned males. Once males emerge in mid- to late summer, the situation will become a little more difficult. Below, I have created illustations that depict the general color patterns of queen and worker bumblebees in Texas. These illustrations, while very simplified, provide an introduction into how the color patterns of females differ. A downloadable/printable version of these illustrations is available:
Quick Guide to the Bumblebees of Texas: Females (Queens and Workers)
Along with these illustrations, I highly recommend studying the bumblebee identification resources created by the University of Illinois’s BeeSpotter. Their more detailed guides include some species not found in Texas, but cover the majority of the state’s species with the exception of the Sonoran bumblebee (Bombus sonorus). Reviewing images of the nine bumblebees of Texas at the website BugGuide is another helpful identification aid.
The first step in navigating these illustrations is assessing the thorax pattern of the bumblebee you are observing. Selection of one of the three thorax types narrows your options as far as abdominal color pattern is concerned. The latter can be somewhat similar among different species, that’s why it is helpful to consult the additional sources I mentioned above to define species identity.
I. Completely yellow or nearly completely yellow thorax; a small bare area may be present in the middle of the thorax:
II. Thorax banded above and below with yellow; center black band present:
III. Upper portion of thorax banded in yellow, remainder black.
