There are large wasps flying around my yard and going into holes in the ground. These wasps are huge. What are they and how can I control them?
As we get into the latter part of the summer and their populations build, we tend to see more and more wasps and bees.
Another reason we see more wasps and bees is that certain ones appear only at this time. This is why we are seeing large wasps flying around now. It is the time of the year for the cicada killer to appear.
This intimidating insect can measure from 11/2 to 2 inches in length and is black or brown, with yellow markings on the abdomen and a stinger measuring a quarter-inch long. Cicada killers typically fly very fast and close to the ground, around knee height.
Sightings are common from mid-to-late summer as the adults are emerging or searching for cicadas. After emerging, the adult wasps will feed on flower nectar, mate and dig burrows preparing for the next generation. Once it is ready to reproduce, the adult female will capture a cicada and sting it. This paralyzes the cicada. The cicada killer then carries the paralyzed cicada to a previously dug burrow measuring 10 inches to 4 feet deep.
The wasp will then lay a single egg on the paralyzed cicada, and then seal the chamber. When the egg hatches, the larva will begin to eat the insides of the still-living cicada for 4- 10 days. Once everything but the outer shell has been devoured, the wasp larva then spins a silken case and prepares to overwinter.
In the spring, the larva begins to pupate and turns into an adult. The next generation of adults will crawl out of the ground and start the process over again. There is only one generation each year.
As frightening as these insects appear, they are typically not aggressive and are actually considered to be beneficial. These wasps will not sting unless cornered or accidentally touched or stepped on. In this case, a cicada killer's sting can be very painful.
The sting is not dangerous unless the victim is known to be allergic to bee stings or shows signs of an allergic reaction. If this occurs, it would be wise to seek medical attention. The only places this insect can pose a real threat are where people, especially children, tend to congregate or play. If one gets too close to a burrow, one might encounter an inquisitive male guarding the area. There is no real need to worry, for he is only bluffing and possesses no stinger.
Though this insect is solitary, it is possible to find groups of wasps in certain areas. I have seen as many as a hundred cicada killers nesting in 50 square feet. A single burrow might be no real problem, but an infestation can become unsightly and possibly even smother turfgrass. This is, however, quite rare, for they prefer to nest in sandy, well-drained soil exposed to full sunlight.
If cicada killers prove to pose a threat to one's safety or the appearance of your lawn, there are many ways of prevention and control. One may use cultural practices to prevent establishment of a cicada killer colony by maintaining a healthy lawn by fertilizing, mowing and properly watering. This promotes a thick turfgrass that creates an undesirable place for cicada killers to nest.
Another option is to apply a good covering of mulch on bare areas. The cicada killers will not burrow through the mulch.
The other control option is to apply a pesticide in the area where they are burrowing. It is hard to control them with aerosol sprays because they fly so fast, so you need to use a dust product or a liquid and treat the soil.
Cicada killers are part of the hunting wasps. There are other hunting wasps in our area such as the mud dauber or dirt dauber. Mud daubers create nest cells out of mud. They catch spiders and fill the nest cells with them. The young mud daubers then feed on the spiders. The downside of mud daubers is they make a big mess with their nest.
These hunting wasps are beneficial. The cicada killer can be fun to watch as it flies back to the burrow with a cicada that is bigger than it is.
Columbia County Extension Agent Charles Phillips can be reached at (706) 868-3413 or by e-mail at firstname.lastname@example.org. The Extension Web address is www.ugaextension.com/columbia.
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