Little metallic green bees: a stunning surprise in your garden

Inside: The metallic green bees in the genus Agapostemon are a vital part of many ecosystems, playing a critical role in pollination. In addition, they’re absolutely gorgeous, making any common flower sparkle in the sunlight.

Have you walked through your garden enjoying the flowers when you suddenly noticed a glint of light? Like an iridescent sequin or a thin strand of tinsel, it flashed green, then disappeared? If so, you may have seen a metallic green bee in the genus Agapostemon.

Nature’s gorgeous green gems

Actually, there are several groups of green bees in North America, many of which are found in the southern and eastern states. But the Agapostemon are uniquely spread across the entire continent, so no matter where you live, you have a good chance of spotting one. These bees are in the Halictidae family (sweat bees) and are native to North, Central, and South America.

Over 45 species of Agapostemon bees live in the Americas, all of which are important pollinators. They are some of the largest green bees in the US, measuring between 0.3 and 0.6 inches long. Both male and female Agapostemon have distinctive coloration, which can vary from bright green to blue-green or even blue-black. In addition, they often have green eyes.

They all look alike, more or less

Many of the metallic green bees are difficult to distinguish, but a few are easier. The bee in the top photo is a male Agapostemon virescens. These bees, spread over most of North America, are called bi-colored striped sweat bees because the male has a black-and-white striped abdomen, while the female abdomen is plain green.

Another unique species is the honey-tailed striped sweat bee, Agapostemon melliventris that lives in the southwestern US. The female has white and honey-colored stripes on her abdomen while the male has black and yellow stripes. Click here to see amazing photos of a mating lek, an aggregation of males waiting for females.

The life cycle of metallic green bees

Like all bees, metallic green bees undergo complete metamorphosis, meaning that they have four distinct life stages: egg, larva, pupa, and adult. Females lay their eggs in the ground, typically in a burrow or tunnel that they have created. The eggs hatch into larvae, which feed on a mixture of nectar and pollen that their mother has provided. Once the larvae have completed their development, they pupate and eventually emerge as adults.

The lifespan of an Agapostemon bee varies depending on the species and environmental conditions, but most adult bees live for several weeks to a few months. During this time, they will mate, lay eggs, and continue to pollinate plants in their habitat.

Habitat and homes of metallic green bees

Metallic green bees can be found in a variety of habitats, including meadows, prairies, forests, and gardens. They are solitary bees, meaning that they don’t live in colonies like honey bees or bumble bees. Instead, each female bee creates her own nest, which is typically located in the ground.

Although each female has her own nest, groups of female bees may share a “vestibule” similar to the lobby of an apartment building. The bees use the same front door, but each goes to her own digs once she’s inside.

They pollinate many kinds of plants

Metallic green bees are important pollinators, visiting a wide range of flowers in search of nectar and pollen. They are especially attracted to flowers in the mint family, such as thyme, oregano, and lavender. I also find them in composite flowers such as dandelions, burdock, and cosmos.

In addition to their role as pollinators, metallic green bees are also important indicators of the health of our environment. Because they are sensitive to changes in habitat and pesticide use, declines in their populations can serve as a warning sign of larger ecological problems.

The stamen-loving bees

The Latin name for the genus Agapostemon means “stamen loving.” Sure enough, these bees are often covered in pollen from head to tail, a sure sign they’ve been frolicking among the stamens.

Let us know when you see your first metallic green bee of the season. And don’t forget to send a picture!

Rusty
Honey Bee Suite

About Me

I backed my love of bee science with a bachelor’s degree in Agronomic Crops and a master’s in Environmental Studies. I write extensively about bees, including a current column in American Bee Journal and past columns in Two Million Blossoms and Bee Craft. I’ve endured multiple courses in melittology and made extensive identifications of North American bees for iNaturalist and other organizations. My master beekeeper certificate issued from U Montana. I’m also an English nerd. More here.