Pennsylvania is home to over 400 bee species, from tiny sweat bees to giant carpenter bees. While most bees play important roles as pollinators, some of the larger species can become nuisance pests for homeowners. Keep reading to learn about the 10 biggest bee species you’re likely to encounter buzzing around Pennsylvania.
1. Eastern Carpenter Bee
The eastern carpenter bee (Xylocopa virginica) is the largest bee species in Pennsylvania. Females reach sizes of 23-35 mm, while males are 19-25 mm long. These robust, dark bees have a shiny abdominal segment and yellow hairs on the thorax.
Carpenter bees drill holes in wood to lay their eggs inside shelters. They prefer untreated softwoods and can damage decks, fences, barns, and other outdoor structures. The females have a stinger but are not very aggressive.
2. Bumble Bee
Bumble bees in the Bombus genus are the second biggest bees in the state. They range from 17-25 mm long with plump, furry bodies. Bumble bee colors include black, brown, red, orange, and yellow combinations.
These fuzzy insects form small colonies and nest in cavities like abandoned rodent burrows. Bumble bees are common flower visitors and important pollinators of crops like tomatoes and blueberries.
3. Cicada Killer
The cicada killer (Sphecius speciosus) is a type of digger bee reaching 19-38 mm in length These substantial bees have a black body with yellow marks on the abdomen Males have more yellow than females.
As the name suggests, cicada killers prey on cicadas to provision their ground nests. The females sting and paralyze cicadas and place them in underground burrows for larvae to feed on.
4. Tarantula Hawk
Tarantula hawks (Pepsis spp.) are spider wasp species, not true bees. But they resemble bees in size (18-45 mm) and habits. These wasps have dark blue-black bodies with bright orange or rusty red wings.
The female tarantula hawk captures tarantulas as food for its larvae It has an extremely painful sting but is not aggressive towards humans
5. Horse Guard Wasp
At 18-25 mm long, the horse guard wasp (Bicyrtes quadrifasciatus) is one of the bigger bees in Pennsylvania. It has a black body with yellow bands around the abdomen. They nest in sandy banks or crumbly soil.
Horse guard wasps prey on ground-nesting bees to provision their own nests. The adults drink flower nectar but are not significant pollinators. Their sting can be painful but they rarely bother humans.
6. Cuckoo Bee
Cuckoo bees in the Nomada genus range from 5-15 mm long. They are kleptoparasites, laying eggs in other bee species’ nests. Cuckoo bees have yellow and black or red and black striped bodies with little to no hair.
By hijacking host nests, cuckoo bees do not collect their own pollen. But they contribute to pollination when visiting flowers for nectar. There are over 130 cuckoo bee species in Pennsylvania.
7. Leafcutter Bee
Leafcutter bees (Megachile spp.) are medium-sized bees of 12-17 mm length. They carry pollen on the underside of their abdomens and have dense hairs for collecting. Leafcutter bees use pieces of leaves to construct nests.
Over 140 species of leafcutter bees exist in Pennsylvania. They nest in cavities like holes in wood or abandoned nests. Leafcutter bees are important native pollinators.
8. Mining Bee
Mining bees (Andrena spp.) dig burrows in soil to nest. They range from 10-15 mm long with hairy bodies in black, brown, or reddish hues. Mining bees transport pollen on their hind legs and belly.
There are over 130 species of mining bees in the state. Their nest tunnels aerate and enrich the soil. Mining bees frequent many flower types but prefer roses, fruit trees, and spring blooms.
9. Squash Bee
The squash bee (Eucera pruinosa) earned its name from pollinating cucurbits like squash, pumpkin, and gourds. These hairy bees reach sizes of 11-15 mm long. They are important specialists for pollinating cucurbit crops.
Squash bees nest underground and emerge synchronously with cucurbit plant flowering. They only collect pollen from plants in the squash family.
10. Large Sweat Bee
Some of the bigger sweat bee species in Pennsylvania include Agapostemon virescens and Halictus rubicundus. They grow to around 10-15 mm long. Sweat bees get their name from drinking human perspiration for its moisture and salts.
Sweat bees nest in soil burrows or rotten wood. They prefer composites like asters and goldenrod. Sweat bees rarely sting but can be attracted to humans, especially during sports and yard work.
Benefits of Large Bees
- Pollination services for wild and crop plants
- Produce honey, beeswax, and other useful products
- Prey on pest insects to maintain ecological balance
- Aerate soil and facilitate decomposition through nest digging
While a few large bee species damage wood or sting, most are not aggressive towards humans. Appreciating the diversity and benefits of native bees of all sizes is key to supporting these important pollinators in Pennsylvania.
Types of Bees in Pennsylvania, New Jersey and Delaware
That’s right, the European Honey Bee, which is also called the Western Honey Bee, is not from the United States. Just like its name suggests, it came to the United States with the first European settlers. These bees have slender bodies with black and orange-yellow stripes around their abdomen. They live in colonies of thousands of honey bees with each type of bee having a role. Each colony has one queen, male drones and female workers. The queen is in charge of having babies, and a drone’s main job is to mate with the queen. The workers take care of all of the responsibilities of managing the hive, except for reproduction. There are approximately 100 workers to one drone. The female worker is the only honey bee that will sting and usually only when provoked.
(Bombus impatiens) There are 14 species of bumble bee in Pennsylvania. The Eastern bumble bee is the most common and easy to spot. Its bodies are round, fuzzy, and black and yellow striped. They are social bees that live in small colonies nested in the ground. Their colonies have an average of 100-200 workers. The queen bumblebee is just under an inch long, and the workers (females) and drones (males) get to be about ½ of an inch long. These efficient pollinators are sometimes confused with carpenter bees. The main difference is that the abdomen of a carpenter bee is smooth and the body of an Eastern bumble bee has short fuzz. The workers will sting when threatened and are able to sting multiple times.
Eastern carpenter bees, Xylocopa virginica, are big bees that look like bumble bees. Their bodies are black and yellow and they are about ¾-inch long. The way to tell the difference is by looking at the bee’s abdomen. While bumble bees are fuzzy all over the carpenter bee abdomen is smooth. These bees live primarily in wooded areas and feed on pollen and nectar. Eastern carpenter bees are not aggressive unless they are provoked. The male, who cannot sting, will swoop as a defensive move. The female will sting and is able to sting multiple times.
(Augochlora pura) The pure green-sweat bee is easy to identify due to its iridescent metallic green body. They are tiny, measuring only . 3” on average. Their name comes from the way they look and the fact that they like salt and will often land on people to lick their sweat for it. These bees are solitary, living in rotting logs in wooded areas. The females will sting if they perceive a threat.
((Osmia) Mason bees have shiny metallic blue or green bodies with patches of fuzz. They have large wings and hairs on their hind legs. Their name comes from their use of masonry materials, like mud, to build their nests. Mason bees are solitary but they will choose to nest near other mason bees. The adult mason bee will grow to about ½ inch. Female mason bees will sting if provoked. They are prolific pollinators of spring fruits and flowers.
(Colletes inaequalis) The plasterer bee is also known as the unequal cellophane bee and the ground bee. Their name comes from the method they use to build their nests. They dig holes in the ground and line their nests with a slimy substance that looks like plastic or polyester. This keeps the walls of the nest dry. Plasterer bees have black abdomens with tan stripes, growing to about ½ inch. They are solitary bees but will nest near other plasterer bees, with groupings sometimes nearing thousands of bees. These bees are pollinators, particularly of pussy willows, red maple trees and various spring flowers. Plasterer bees are not aggressive and will not swarm.
Another name for leafcutter bees is megachile bees. They get their name from the way they build their nests. They are solitary bees who chew leaves to build nests within rotting logs or old trees. They have slender bodies with black and pale yellow stripes. They don’t use their back legs to carry pollen; instead, they use the short hairs on the stomach. These bees are small, growing to just under ½ inch. Leafcutter bees will sting but only when they perceive a threat.
(Peponapis pruinosa) The squash bee, as their name hints, is a primary pollinator of squash, pumpkins and gourds. They also have a “squashed” appearance to their black and yellow bodies. They grow to about ½ inch and have a smooth abdomen and fuzzy thorax. They do not have stingers and so do not sting. They are solitary bees and the females build their nests in the ground. Squash bees are often more active when it is dark.
(Anthophora plumipes) The hairy-footed flower bee is often confused for a bumble bee given their similarity in appearance. The hairy-footed flower bee is different from the bumble bee because it flies quickly and darts around. Also, males and females look different. Both males and females are dark brown to black with tan stripes across the abdomen. Males have reddish brown or gray hair, while females only have black or dark brown hair. They will grow to about ½ inch. Hairy-footed flower bees are solitary, building nests in spaces with clay and mud. The females will sting but only when provoked.
Signs of an Infestation
It’s likely that you have bees because there is a hive nearby or the bees are looking for a warm place to nest.
Here are the signs to look for:
- Large numbers of bees outside, close to your home. This could mean that there is a beehive close to or inside your house.
- Holes drilled in the wooden parts of your house, especially the eaves The work of carpenter bees.
- Dark stains and slight bulging of walls, ceilings or floors. This is the result of honey seeping through.
- Buzzing sounds within your walls
It is always best to be safe. Contact a pest control professional to evaluate the situation.
No, those giant wasps in your yard are not ‘murder hornets’ | VERIFY
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