Bees are commonly associated with flying around flowers and plants, but did you know that some types of bees prefer to create their nests in the ground? Even in the United States, ground-nesting bees are widespread, with some species being utterly harmless to humans. However, some bees can exhibit territorial behavior and aggression toward potential threats.
This article will explore various types of ground-nesting bees, including those that may pose a risk to humans. So, read on to discover more about these captivating insects!
1. Africanized Bee (Apis mellifera scutellata Lepeletier)
Let’s start with the most aggressive bee in the United States or perhaps worldwide. The Africanized bee, also known as the “killer” bee, results from the interbreeding between bees from southern Africa and local Brazilian honey bees.
Distinguishing between Africanized bees and domestic honey bees can be challenging as their physical appearance is quite similar. However, there is a subtle difference in body size between the two, with Africanized bees being slightly smaller. The Africanized bee has a distinctive coloration, with a golden yellow body and darker bands of brown.
On average, adult Africanized bee measure approximately 0.75 inches. The lifespan of female worker bees is typically around one month, while male drones can survive for 5-10 weeks. In comparison, the queen bee has a longer lifespan of 1 to 3 years.
The small colony size of Africanized bees makes them capable of constructing nests in unconventional locations. These bees have been observed to inhabit a range of objects, including crates, tires, tree limbs, boxes, overturned flower pots, junk piles, mailboxes, empty cars, and holes in the ground.
Like other honey bees, Africanized honey bees are essential pollinators and feed on both nectar and pollen from flowering plants. As they move from flower to flower, Africanized honey bees facilitate the transfer of pollen, which is crucial in pollination, leading to the production of fruits, seeds, and other plant products.
Is the Africanized Bee Aggressive?
Africanized bees are known for their aggressive behavior towards perceived threats. More than 1,000 people have lost their lives because of these killer bees. These bees are more likely to attack than any other bee out there. When an Africanized bee colony feels threatened, it will release a pheromone that signals the entire colony to attack.
These bees can pursue their target for considerable distances, often up to a quarter of a mile. They will repeatedly sting, inflicting considerable pain and, in some cases, resulting in severe allergic reactions or even death. Therefore, it is essential to exercise caution around Africanized bees and seek professional help if you encounter a swarm.
2. Sweat Bee (Halictidae)
More than a thousand species of sweat bees thrive in temperate regions in the United States. These bees are typically slender and have a metallic black appearance, though some species can be seen in a beautiful metallic green, blue, or purple color. The average size of these bees ranges from ¼ to ¾ inch.
Most sweat bees prefer to build their nests in underground burrows within sun-exposed, bare soil. However, some species will also nest in decaying wood, while others are cleptoparasites that lay their eggs in the nests of other bees.
Like many other bee species, adult sweat bees feed on nectar and pollen, facilitating the pollination of flowers. Interestingly, these bees also have a unique behavior where they seek out salt sources to supplement their diet. Some sweat bees even try to obtain salts from sweating humans, similar to how athletes drink electrolyte beverages or deer visit salt licks.
While certain sweat bees may establish basic colonies where a single bee serves as the queen, they maintain the capacity to lay eggs, distinguishing them from honey bees.
Is the Sweat Bee Aggressive?
Some species of sweat bees may exhibit aggressive behavior towards humans as they love to consume the salt in human sweat. In some cases, when sweat bees search for a source of salt, they may accidentally land on humans and start crawling around or even trying to consume the sweat on their skin.
This can be startling and uncomfortable for some people, leading to them swatting at the bees or trying to brush them away. Such movements can provoke the bees to sting, causing pain, swelling, and even allergic reactions. Therefore, it is essential to remain calm and avoid swatting or flailing around when sweat bees are in close proximity to you.
3. Bumblebee (Bombus)
The bumblebee genus Bombus is part of the bee family Apidae and includes more than 250 species. Bumblebees vary in appearance but are typically round and densely furry. They have a larger, broader, and sturdier body structure, with a more rounded tip to their abdomen. The patterns and coloration of broad bands help distinguish between different species.
Bumblebees have none or fewer stripes than other bees, with parts of their body typically covered in black fur. Within species, sizes can vary significantly; for example, the queen of the largest British species, B. terrestris, can reach up to an inch in length. On the other hand, the world’s largest bumblebee species, B. dahlbomii, is found in Chile and can grow up to 1.6 inches long.
Bumblebees nest in various locations, with some choosing to nest underground in abandoned rodent holes or compost heaps, while others prefer to nest above ground in bird boxes, trees, or thick grass.
Bumblebees primarily feed on pollen and nectar from flowers. Therefore, growing plenty of bee-friendly flowers during bumblebee season (between March and October) is the best way to help these and other pollinating insects thrive.
Although the majority of bumblebees create colonies, certain types, known as cuckoo bumblebees, are brood parasites and do not construct their own nests. Instead, their queens invade the nests of other bumblebee species, eliminate the resident queens, and deposit their own eggs, which the resident workers subsequently nurture.
Is the Bumblebee Aggressive?
Although bumblebee species are generally not aggressive, they may sting in self-defense if they feel threatened or if their nest is disturbed. Both queen and worker bumblebees can sting, but their stingers lack barbs, enabling them to sting repeatedly without injuring themselves.
4. Miner Bee (Andrena)
Belonging to the family Andrenidae, Andrena is a genus of bees comprising more than 1,500 species, thereby ranking among the largest animal genera. These bees are typically small and dark-colored, with distinctive banding and varying degrees of hairiness, which can make them easily mistaken for small honeybees or wasps.
Experts can identify miner bees by the dense bristles on their leg bases, the shin-like sections of their legs, specific creases and grooves on their face and head, and unique wing vein patterns. On average, these bees are between ⅜ to ¾ inch in size.
All Andrena species are solitary, ground-nesting bees that exhibit a preference for sandy soils. While some may nest communally or in aggregations, there are no social or parasitic species within this genus.
Miner bees do not cause any harm to gardens or soil, and their presence can be observed through the small earth mounds they create in borders, lawns, and pots. In addition, you may notice holes in bare patches of soil.
Unlike wasps, Andrena bees are vegetarians and feed on floral pollen and nectar. While some species may consume an array of different flower types, others may have a specific plant preference.
Is the Miner Bee Aggressive?
Miner bees are generally friendly and non-aggressive towards humans and do not usually sting or bite. While they can sting, they typically only do so when their eggs are threatened, and even then, stinging is rare. If they do sting, the pain is usually mild, and there is little to no swelling.
5. Mason Bee (Osmia)
Mason bees are part of the Osmia genus, which belongs to the Megachilidae family. They are ground nesting bees known for their metallic green or blue appearance, although some are black or rust-red. While they may be difficult to notice, they have black scopae on their underside for carrying pollen.
Mason bees are between 3/8 and 5/8 inches long, with males being smaller than females and having light-colored hair on their faces.
These bees are referred to as mason bees because they construct their nests using mud or other “masonry” materials, typically in natural crevices like small cavities or cracks in rocks. When possible, they may also utilize holes created by wood-boring insects.
Mason bees are efficient pollinators, visiting many cultivated garden plants and spring flowering shrubs and trees, particularly apples and pears. They are also found in agricultural orchards and oilseed rape fields.
Unlike other bee species that have worker bees, Osmia species are solitary. Each female is fertile and builds her own nest. Osmia pollination efficiency is due in part to their unique anatomy and behavior. Unlike most bees that collect pollen from their hind legs, female Osmia and other Megachilidae bees collect pollen using abdominal scopa hairs.
Is the Mason Bee Aggressive?
Female mason bees have a stinger for self-defense but are not known for being aggressive. They are happy to coexist and forage near humans, making it unlikely that they will sting. In the rare event that a mason bee does sting, it is relatively painless and feels more like a small pinch than a honeybee sting, which is much more painful.
6. Long-Horned Bee (Eucera longicornis)
Last on the ground-nesting bee list is the long-horned bee belonging to Apidae family. Long-horned bees are easily recognizable by the long antennae on the males. In addition, the thorax of the male bees is covered in light brown hair, while their abdomens have sparser, light brown hair that can turn silvery white when exposed to sunlight. Females do not have extra-long antennae but are similar to males in appearance, with a sturdier frame. The adult long-horned bee measures around 0.5 inches in size.
The female of this species creates a burrow in clay soil and smoothes the walls. She provisions it with a mixture of pollen and honey made into a paste and lays an egg on top. The larva feeds on the paste after hatching and usually spends the winter as a pre-pupa in the burrow. Pupation occurs in the spring, and the adult emerges soon after.
They are found in various habitats, such as soft cliff faces, coastal grasslands, woodland rides, heathland edges, and sometimes even in brownfield areas.
Long-horned bees feed on various flowers, including bugle, comfrey, and bramble. Still, they seem to have a particular preference for plants in the pea family, such as vetches, clovers, everlasting peas, and bird’s foot trefoil.
Bee orchids (Ophrys species) are known to deceive male long-horned bees. These bees are attracted to the flowers due to their similar shape, color, and size to actual bees. Moreover, the orchids release pheromones that trick male bees into believing that they have found a potential mate.
Is the Long-Horned Bee Aggressive?
Although long-horned bees may appear intimidating to some people, they are generally quite gentle and non-aggressive toward humans. They often live in close proximity to humans and do not attack or sting unless they feel threatened or disturbed.
Summary of 6 Types of Bees That Nest in the Ground
Here’s a recap of the six ground-nesting bee types that we took a look at.
|Number||Bee||Scientific Classification||Level of Aggression|
|1||Africanized Bee||Apis mellifera scutellata Lepeletier||More than 1,000 people have lost their lives due to these killer bees known for their aggressive behavior.|
|2||Sweat Bee||Halictidae||Some species may exhibit aggressive behavior toward humans as they love to consume the salt in human sweat.|
|3||Bumblebee||Bombus||Usually not aggressive, they may sting in self-defense if threatened or their nest is disturbed.|
|4||Miner Bee||Andrena||Generally friendly and non-aggressive towards humans, they do not typically sting or bite.|
|5||Mason Bee||Osmia||Female mason bees have a stinger for self-defense but are not known for being aggressive.|
|6||Long-Horned Bee||Eucera longicornis||Although they may appear intimidating, they are generally gentle and not aggressive toward humans.|
The photo featured at the top of this post is © HWall/Shutterstock.com
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