Written by Joe Ballenger
Your Name: Clark
Your Bug Question: I noticed a small flying insect about the size of a honey bee, fuzzy, all black flying around with a small leaf in its legs. It flew down between some small rocks next to a cement pad and dissapeared. It flew out a minute later without the leaf and returned with another leaf or section of a leaf. I watched it repeat this several times. Any idea what this insect is and what it is doing?
As Nancy wrote, IDing insects can be very hard because you often need to see tiny features of the insect most people wouldn’t think to photograph.
Thankfully, not all bugs are this way. Some insects have behaviors that are pretty unique, and can be used to ID them with a surprising degree of certainty. The behavior that Clark is describing is one such example. It doesn’t happen too often…but we love it when it does.
Leafcutting bees, family Megachilidae, are pretty unique among bees because they snip off pieces of leaves to line their nests. Like other bees, they also feed on pollen and nectar. The larvae eat the pollen, and the leaves are used to give them a comfy little house to live in. Some like to build nests in cracks and crevices, others like to build their nests in hollow plant stems, and others take over old nests left by carpenter bees. One species even uses old snail shells to build its nests.
Not all of these bees are pollinators, however. Several species are parasitic, and take over nests from closely related species. The Cuckoo-bees, Coelioxys sp., are probably the best known example.
My favorite Entomo-YouTuber, Nature1UpClose, has an excellent video which describes the lifecycle of this bee. They’re very important pollinators, especially in agricultural situations. They do cause some damage to the plant by removing leaves. Because they pollinate the plants, they’re usually more of a benefit to the system than they are a pest.
Megachilids are pretty cool…and they’re one of the bees that’s not talked about too frequently when talking about pollinators.