Extensive rains delayed them a bit, but our annual cicada cycle started up with vigor sometime in the last ten days. For the past three years, we get the announcement at our house, not from the cicadas singing from the trees, but from the cicada-killer wasps that buzz our back patio area, scouting the yard for good places to bury their prey.
It started with one female burying cicadas under the patio; perhaps another joined her by the end of the first season. But last year, we had about a dozen buzzing about the yard. We have plenty of cicadas, so it should be good pickings for the wasps — so long as no one sprays insecticide on them.
These wasps are larger than most wasps, as long as 2.5 inches, and big enough to muscle a cicada around. The cicadas are twice as big, volume wise, but I suspect they weigh less. In any case, the wasps show outstanding strength and coordination in zooming around carrying their paralyzed victims to their holes — yesterday I saw a wasp rocket into a hole in the garden without the usual stop to drop the cicada and tug it in. The hole was a perfect fit. Jet air delivery.
The wasps leave us alone as we watch. We’ve never been stung, and I don’t know that these guys sting humans (unless attacked, and I assume they’d fight back).
Their ability to move dirt is amazing. We usually get a pile of soil about a foot around and three to six inches high at each hole.
So far as I know, down here in Dallas we don’t get any massive infestations of the the 13- or 17-year cicadas. I cannot imagine how such a feast might affect these industrious little guys, other than they might fly themselves to death. We lived through a double hatching of the 13- and 17-year cicadas in Maryland. Corpses of the cicadas made some streets slick enough they were dangerous to drive. Man, what I wouldn’t have given for a few thousand cicada killers then!
Cicada killers, or cicada hawks, sting and paralyze cicadas, then inter the still-living cicada with one egg laid in it for male larvae, or one egg with two cicadas, for female larvae. The wasp egg hatches and the larva consumes the fresh cicada; some of the wasps survive the winter, and I don’t know if the cicada is kept fresh the entire time, or if a few of the wasps hatch and go dormant.
My photos didn’t turn out as well as those from Purdue and Michigan State — the buggers are fast and restless. The photos could easily have come from our yard, with the massive blossoming of the yellow composites right now (“DYCs” in local horticultural parlance).
Watch your yard — you probably have these tiny “True Life Adventures” going on in your own backyard. You can encourage them with careful plantings, and especially by not spraying poisons (did I mention that between the predatory insects and the now-large geckoes that have taken up residence here, we don’t have cockroaches and other nasty house pests?).
The photo below shows a wasp carrying a cicada.
Update on resources (7-30-2008):