We finally returned from our summer in Italy, to find the garden full of weeds — no surprise there — and large black wasps on the milkweed flowers. The same flowers also were buzzing with carpenter bees, which looked almost small compared to the wasps. If you are familiar with carpenter bees, then you know that, in the world of bees, they are giants.
To see such large wasps flying among the giant bees was, at first, alarming. When I realized what they were, though, I moved in for a closer look.
The name of the large black wasps is Great Black Wasp.
What do Great Black Wasps eat?
As adults, these wasps are vegetarian, eating nectar and pollen. When they move from flower to flower, the wasps carry pollen on their legs and bodies and pollinate the flowers. This means they are yet another of our beneficial garden insects.
As larvae, they are not vegetarian. They eat grasshoppers, cicadas, and katydids. When a female adult Great Black Wasp finds an insect like a katydid, it paralyzes the insect/prey using its stinger. Then, it carries the insect/prey to a burrow it has dug in the ground, where it lays an egg.
When the wasp egg hatches, the larva that comes from the egg will eat the insect. A hatched wasp larvae can eat more than one insect, so the adult will stuff at least one more insect down the burrow, and as many as five more, for each wasp egg.
Where do Great Black Wasps live?
Great Black Wasps live across much of the United States and into Canada, but they are not commonly seen in the upper part of the Western U.S.
Great Black Wasps are in the group of wasps called Digger Wasps. These are mostly solitary wasps, each female digging its own holes in the ground for its eggs. Digger wasps don’t live together in one place, they are not honeybees in a hive, but they sometimes congregate. In a way, they are kind of like the suburbanites of bees, each with its own space, but grouped in a way that feels less lonely.
Are they really as big as I think they are?
If you are like me, when you see your first Great Black Wasp you will think it is at least two inches long. If you have seen a female, the surprise will trick your mind into believing the fish tale — “it was THIS BIG!” In reality, even though females are larger than the males, the biggest Great Black Wasps are closer to an inch and a half long.
Do Great Black Wasps sting people?
If you do something crazy like chase one around with a camera, it might (or it might not!), but these wasps are busy with their own agendas. If you leave them alone, they will keep doing their work of eating nectar and pollen, digging burrows for their babies, and hunting insects.
The time of greatest activity for these large black wasps is now. By the middle or end of September (depending on where you live), the adults will no longer be flying. Their job of laying eggs and providing food for their larvae will be done. The babies, though, will emerge next summer, and then there will be more Great Black Wasps on my flowers.
Other beneficial wasps you may see at the end of summer include the potter wasp and blue winged digger wasp.