What Are Digger Bees?
Digger bees (also known as long-horned bees) are typically large, unusually fuzzy bees that tend to nest in soil—hence their name. They are found all over the world. There are thousands of species of digger bee, at least 900 of which are found in North America.
This classification includes miner bees, yellow-faced bees, sweat bees, and plasterer bees—among many others. Digger bees are excellent pollinators, said to be even more beneficial to us than honeybees and bumblebees.
Speaking of which, although they are of the same family as honeybees and bumblebees (Apidae), beekeepers (and enthusiasts) are simply fascinated by their atypical behavior. They stand out in their appearance, societies, and habits, and are almost nothing like their more common cousins.
What Do Digger Bees Look Like?
Apart from a few traits that we can use to identify them, remember that “digger” is a general term used to describe a number of different species. If you want to identify the exact type of bee, you’ll have to look at the defining traits of the individual kind.
There are some general characteristics. Digger bees range from the size of a honeybee to about the size of a bumblebee. They’re said to be anywhere between a quarter and a half-inch long.
Although they are most commonly fuzzier than most bees, some of them are shiny or metallic. The patterns, markings, and fur all depend on their species. Another giveaway is that digger bee males have enlarged antennae.
It’s worth paying attention to the individual bees though. Let’s have a quick look at the most common types of diggers.
Mining bees are on the smaller side of digger bees, usually between 0.3 and 0.7 inches long. Their bodies are metallic black (but can also appear as blue or even green), and they have a moderate amount of fur on their abdomens. Their hairs are light but can range from orange-brown shades to almost white.
Yellow-faced bees resemble wasps. They are slimmer than our friends, the honeybees, bumblebees, and carpenter bees, and have sharper, arrow-shaped bodies. They don’t have as much fur as expected from bees, and they’re named for their distinct mask-like yellow markings on their faces.
You could say that sweat bees are the most “bee-looking” of the diggers, but within their family, their markings and traits differ so much that no two sweat bee species look the same either. They are furry, and often have the typical black and yellow stripes of more common bees.
Often their stripes are clearer and more distinct than those of honeybees, but not quite as bright as bumblebees.
This is just an overview of how digger bees can appear to us. If you really want to be sure that you’ve come across a digger, its patterns won’t help much (unless you study each one closely and are able to instantly tell them apart).
It’s much better to determine diggers by their most obvious characteristic: their digging.
Digger Bee Nests
It’s easy to confuse ground-nesting bees with digger bees, but they’re not the same thing. You could say that all diggers are ground-nesting, but not all ground-nesters are diggers, as is the case with bumblebees and carpenters.
One of the most important identifiers is their solitary status, but it requires some explaining to understand why they’re so special. I mean, carpenters are ground-nesting solitary bees too, so how come they aren’t considered diggers?
Here’s the fascinating truth—digger bees are social solitary bees. They nest alone, but within close proximity to each other, giving us the impression that they live in colonies, even though they don’t.
Since they nest in soil, their nests will take on the appearance of a series of mounds in the ground, with their entrance holes obvious and uncovered. Not all digger bees will nest in the earth though. Some are known to dig into wood, and others are parasitic and don’t dig at all.
Digger bees still build wax cells under the soil and, much the same as other bees, these cells are used for the storage of brood and food.
Digger Bee Society
Since digger bees don’t live in colonies, they don’t follow a queen and have no workers. Their behavior is almost the opposite of colony bees, since they have no hive to maintain.
Digger bee females are in charge of building nests and cells, and just as in other bee societies, drones do not have much of a purpose beyond reproduction. It’s interesting, though, because digger drones take far more initiative in mating than others.
It’s been studied that digger drones make the first move. They scout out females: they can sense them underground, and will wait for them to emerge with precision. When the females reach the surface, males become territorial and are known to fight over the females.
In general, solitary bees have short lifespans that are just as focused on reproduction as colony bees. Once they have mated, they die off and new bees will continue the cycle.
Facts About Digger Bees
It can be tricky to find information on digger bees because they’re not as popular, liked or respected as honeybees. Here are some answers to common questions you might have concerning digger bees.
Do Digger Bees Make Honey?
Although diggers are related to honeybees, they do not produce honey. In fact, honeybees are the only bees known to produce honey as we enjoy it. Even though diggers don’t produce anything that we can directly harvest, they are efficient pollinators and we have a lot to thank them for (like our food).
They do, however, secrete wax (or a wax-like substance) that they use to construct their underground cells.
Are Digger Bees Dangerous?
Digger bees are not known to be aggressive, but of course, it comes with the usual disclaimer that if provoked they will attack. They are more docile (and their stings hurt less) than other bees, but there is a different sort of risk.
More aggressive ground-nesting insects (like yellowjackets) are often mistaken for passive diggers. If you stumble upon mounds in or around your property, be extra cautious. You could be dealing with wasps. Although they’re not much more aggressive by nature, it is easier to provoke them and their stings are much more unpleasant.
Are Digger Bees Endangered?
There is no evidence to suggest that digger bees are endangered, but that doesn’t mean that they aren’t under threat. The factors that put other bees on endangered lists (climate change, human interference, deforestation, etc.) can still affect diggers.
Their biggest threat is humans, though. They look (and sometimes behave) like wasps, so digger bees have an unfair reputation of being dangerous. When people who are unaware that they’re docile discover them, they panic and order their removal.
While it’s understandable that not everyone is comfortable having bees around, digger bees won’t interfere with us (or damage our property) if left to their own devices. Unfortunately, there is not much awareness regarding this, and many digger bees are killed off because of our ignorance.
Digger bees are fascinating because they are so different from the bees we usually hear about. They nest underground, in aggregations, and the males are a lot more dominant than in other species. They make fantastic pollinators, and their unconventional appearances sure do get them to stand out.
Still, there is little information available regarding digger bees as a whole. If you want to know more you’ll have to study the individual species. These bees need more awareness so that others will learn not to fear them, or unfairly kill them.