Don't fear, the pelecinid wasps are here
The mild days of early September are a great time for us to notice the insects of late summer. Now grasshoppers, locusts and crickets abound in the meadows and roadsides. A few also come into our yards and maybe even our houses. Katydids buzz, ch...
The mild days of early September are a great time for us to notice the insects of late summer. Now grasshoppers, locusts and crickets abound in the meadows and roadsides. A few also come into our yards and maybe even our houses. Katydids buzz, chip and creak in these same grasses. And dragonflies of two kinds, the large blue-green darners and the small red meadowhawks, patrol their territories looking for bug meals.
Though the hot summer days are starting to wane, the whining drone of cicadas can still be heard among the leafy trees. Here, too, are hornet nests that grew all summer. Now gray and about the size of a football, these leafy colonies hold the last brood of the season. With this batch grown and leaving home, the workers that cared for growing siblings all summer now go off for sweet meals of their own. Fond of juices, they frequent berry bushes, apple trees or gardens. They also appear to like the taste of soft drinks, making them unpopular with those who would rather not share their snacks with hornets (or their cousins, the yellow jackets).
This is also the time when we might see one of the strangest insects of the year. Out in lawns is a black wasp with what appears to be an extra-long tail or stinger. The pelecinid wasp has the characteristic thin body, long antennae and clear wings as expected, but the female also carries an extremely long tail. Her 1-inch body holds an extended appendage twice that size.
This egg-laying ovipositor is neither a tail nor a stinger. Though many would assume this weird wasp to be dangerous, it is harmless. Like their cousins, the ichneumon wasps, pelecinids take this long tube and use it to strategically place eggs in the soil. Short grasses of our yards serve this egg-layer just fine. Here she walks until locating the right spot. Next, she plunges her ovipositor down and eventually deposits a single egg and flies on to another site. With such a long appendage, her wings are just barely able to lift the tail when airbound. While resting, the wasp conveniently folds the ovipositor into six parts and tucks it under her body.
Finding the right spot on the soil is imperative for a successful reproduction. The eggs appear to be placed at random, but they are actually put within the skin of a larva living in the ground. By some unknown method, she is able to find the immature stage of May beetles or June bugs. Eggs deposited at the correct sites will hatch and devour the host insect within this subsoil world.
Males, which are black like the females but lack the long ovipositor, go unnoticed by us at this time.
The female will continue to be in our lawns for a few more weeks, but usually by mid-September they fade from the scene. Their offspring will continue to grow below the surface and emerge next year.
Retired teacher Larry Weber is author of several books that are available now: "Butterflies of the North Woods," "Spiders of the North Woods" and "Fascinating Fungi of the North Woods." He lives in Carlton County.