The Violet Carpenter Bee, or Xylocopa violacea, is a lovely, big, black, shiny bee whose wings have a pretty blue-violet sheen to them. It is a member of the Apidae bee family (along with honey bees and bumble bees).
Bees exhibit a stunning range of colors and patterns, from the familiar black and yellow stripes of honey bees to the metallic blues and greens of sweat bees. Among this diversity, black and blue bees stand out for their dark, striking appearance. But what species have this coloration, and how can you identify them? This article will explore some of the key black and blue bee species and provide tips on recognizing them.
Why Are Some Bees Black and Blue?
The reasons behind bees’ coloration are complex, but two main factors come into play. Firstly, the colors serve as camouflage or warning signals. Bright bands and patterns help bees blend in with flowers and foliage, while dark colors may warn predators that the bee can sting.
Secondly, the colors are structural. The blues and greens result from the way light reflects off the bees’ anatomies while black comes from underlying pigments like melanin. So in a sense, many bees are naturally predisposed towards black and blue hues.
Characteristics of Black and Blue Bees
Many black and blue bee species share some common traits
- Smooth, hairless abdomens with little to no striping
- Dark blue, black, or green metallic coloring on heads, thoraxes, and abdomens
- Stout, compact bodies shaped like bullets
- Often solitary nesters in holes in wood or the ground
- Usually sting only when threatened
However, there is variation between the different genera and species. Examining the bees up close reveals key differences that aid identification.
Types of Black and Blue Bees
Here are some of the most common black and blue bee species you might encounter:
Carpenter Bees
Carpenter bees in the genus Xylocopa have shiny black abdomens and thoraxes with dense hairs. They are large, robust bees around 13-25mm long. Males have yellow facial markings while females are solid black. Their nests in wood give their name away!
Small Carpenter Bees
Ceratina species are tiny, slender bees 8-10mm long. Their abdomens are black but often have blue or green metallic tones. Instead of tunnelling wood, they nest in stems and twigs.
Green Metallic Sweat Bees
Bright green Augochlora sweat bees are attracted to sweat and congregate on humans. Despite their small size at 5-7mm, they can give a decent sting! Their abdomens are banded black and pale yellow.
Blue-Black Mason Bees
Osmia bees like Osmia nigrifrons and Osmia nigrobarbata are black mason bees with bluish-black heads and thoraxes. The females have dense orange-red hairs on their undersides ideal for gathering pollen.
Black-Tailed Bumble Bees
Bombus melanopygus is one species of bumble bee with striking black abdomens and thoraxes and bright yellow-orange thoraxes. Workers have a characteristic white tail.
Tips for Identifying Black and Blue Bees
-
Examine the bee’s size and body shape – is it large and robust like a carpenter bee or small and skinny like a Ceratina bee?
-
Check for any stripes, bands, or abdominal markings in addition to the black/blue coloration.
-
Look at the amount of hair on the body – very hairy bees like bumble bees can also be predominantly black.
-
Note any metallic green or blue sheens to the black sections.
-
Pay attention to behavioral traits like nesting in wood or congregating on humans.
-
Use identification guides and experts to confirm hard-to-differentiate species.
-
Be aware that color variations exist even within a species – some individuals may not follow the typical patterns.
-
Take clear, close-up photos to capture diagnostic details and compare against reference images.
The Value of Black and Blue Bees
While often overlooked for more vibrantly colored species, black and blue bees play vital ecological roles. Their pollination services help sustain many plant populations, including crops. Supporting native bee diversity in your area can have tangible benefits for your whole ecosystem.
So next time you come across a shiny black insect buzzing among the flowers, take a moment to appreciate the beauty and utility of these unique bees. A diverse tapestry of different forms, behaviors, and traits come together to form the complex bee communities that maintain healthy environments for all living things.
Distribution, Identification And Life Cycle of Life Cycle Of The Violet Carpenter Bee – Xylocopa violacea
This species usually lives near the Mediterranean Sea and the Black Sea, but it is slowly spreading to northern Europe, including Poland, Belgium, and Germany. There have also been reports of a few individuals in Sweden, one female in Finland, and several individuals in Britain, which is likely due to the importation of wood or plant products rather than natural migration1
The violet carpenter bee looks a lot like the splay-footed carpenter bee, which is also found in Europe and is a different species. To tell the difference between females, you would need a microscope, but the antennae make it easy to tell the difference between males. You can tell it’s a male violet carpenter bee if the tips of its antennae have a hint of red.
In the picture below of a male and female violet carpenter bee mating, notice how the tips of his antennae are tinged with red. He is also holding the female’s antennae.
Below is a lovely short video of a violet carpenter bee busily foraging on flowers. Note the distinctive flight and beautiful wings.
When it comes to southern Italy, the breeding season starts in late January or early February and ends in late April2. Males compete very hard to mate with females during this time, and males will sometimes try to stop couples in flight3.
Females search for suitable nest sites until June2.
Even in cooler climates, females may emerge relatively early. In the UK females have been observed to forage on a comparitively warm, late February day in England4.
In Xylocopa violacea, there is only one generation and one flight period each year. Like other Xylocopa species, the females only lay 7–8 eggs on average per nest5.
From the Greek word for “woodworker,” which is how this species builds its nests, comes the name “Xylocopa.”
This bee might be a woodworker in two main ways. First, it digs holes and tunnels (which may include branches) in rotten wood and tree branches to make its nest.
Secondly, it fashions nest cell partitions inside the tunnels, from the chewed wood fragments. These partitions measure about 2mm think in middle, but are about twice as thick around the edge4. The length of each individual larval cell has been found to measure from 14 to 20 mm4.
Bamboo canes5 are also sometimes used for nests in dry places, along with plant stalks from yucca and palm trees.
One person who has written a lot about this species (Vicidomini2) keeps track of a lot of different ways they protect their nests.
The foundress female may make buzzing sounds from inside the nest to scare away other females that are trying to get in. If an intruder female perches by the entrance to the nest, the foundress female will rush forward to attack. This is usually sufficient to send the visitor on its way.
Persistent males may additionally engage in a spiraling attack flight. Larger intruders (such as humans) might witness the female flying around them, but at a distance.
STUNG by a BIG BLUE Bee!
FAQ
What kind of bee is black and blue?
Are blue carpenter bees aggressive?
Are violet carpenter bees aggressive?
Is a carpenter bee sting harmful?