This week we have two featured insects for you: a wasp and a bee that looks an awful lot like a wasp.
Common name: Masked or yellow-faced bees
Nest type: Silk (dried mother bee saliva)
Size: 3/16″ to 3/8″ in length
Nest tunnels used: 1/16” to 1/4” tunnels
Looks like: Nearly hairless yellow-faced or masked bees (very wasp-like)At first glance (or the second, or third, or fourth) Hylaeus bees might fool you into thinking they aren’t bees at all. You wouldn’t be crazy for thinking so: the “masks” on their face are similar to many wasps, and they’re nearly hairless. Most bees transport pollen externally, either on the underside of their abdomen or on their hind leg. Since these gals don’t have much hair, how do they bring home the bacon (er, pollen)? If you’re familiar with how mother birds feed their brood, Hylaeus use a similar technique. The mother bee eats nectar and pollen—which is very high in nutrients, and stores it in a special stomach-like organ called the crop. When she returns to her nest, she regurgitates the nectar/pollen into her silk lined cells. They nest in natural cavities like hollow twigs—or, even better, our bee blocks!
Our second insect of the week parasitizes Hylaeus:
Scientific name: Gasteruption
Common name: sometimes called “carrot wasps” (probably because they like to nectar on carrot flowers)
Nest type: parasitize any available Hylaeus nests
Size: 1/2″ to 1″ body, may also have an ovipositor that extends up to another inch in length
Nest tunnels used: parasitize any available Hylaeus nests
Looks like: Black wasps often decorated with orange
Like the remarkable ovipositor of Leucospis wasps that we saw a couple weeks back, some Gasteruption wasps use the same sort of strategy to lay eggs in Hylaeus nests. Other species have short ovipositors and must enter the nests when the Hylaeus mum is out foraging for pollen/nectar. These gasteruptions almost float on the air, then sit motionless outside Hylaeus nests until the female bee leaves to forage. The female Gasteruption then creeps into the Hylaeus nest, lays an egg and scrams, before the unsuspecting bee returns. As the wasp larva grows, it will feed on the pollen and nectar meant for the bee larva. Sometimes if they’re feeling really hungry, they don’t just limit themselves to one cell, but eat the contents of several bee cells. This is one reason why they vary so much in size!