Sunday, August 31, 2014
Double-banded Scoliid Wasp
Well, it may look menacing because it's a big, black wasp, but the main animals that scoliid wasps menace are beetle larvae, especially beetle larvae in the ground. You know, those things in your lawn called grubs?!
Every summer, Double-banded Scoliid Wasps are frequent visitors in my yard, especially to goldenrod and brown-eyed Susan blooms. I doubt it's a coincidence that I rarely see June bugs any more, no matter what time of year it is. Apparently, the female scoliid wasps dig down into the soil, sometimes following a grub's own tunnel, find the beetle grub, and then sting the grub to paralyze it. The female often lays an egg on the grub then - but not always. Even if the female doesn't lay an egg, the grub will never recover from being paralyzed and therefore will never mature to reproduce.
Scoliid wasps, it naturally follows, are important predators on June bugs, May beetles, green June bugs, and even Japanese beetles!
According to BugGuide.net, there are 20 species of scoliid wasps in the U.S., spread among 5 genera, so there's a good chance you, too, can have scoliid wasps in your yard and garden. Insects in Kansas shows 3 different species, in 2 genera, but there are probably more in our state.
By the way, if this wasp still looks dangerous to you, this is another of the myriad of solitary bees and wasps that won't sting you unless you physically try to hold them in your hand or accidentally step or fall on them. Scoliid wasps are not aggressive towards humans.
Scoliid wasps are wonderful natural predators. I hope you discover a species or two of these beautiful animals sharing your garden too!