We live in zone 6a and I have been gardening and cooking for years. This blog is an opportunity for me to share with you my success and those failures that come about on occasion. Plus, I want to hear from all the gardeners and bakers and cooks out there and learn from you. Feel free to share your ideas.

Saturday, August 18, 2012

Cicada Killer Wasp

I had never heard of Cicada Killer Wasps and the past couple of weeks while in the garden, I noticed a very large flying insect that I thought was a horsefly. However, the closer I looked, it did not resemble anything  I had seen before. Our neighborhood now has been visited by Cicada Killer Wasps. The males do not sting, but they will dive after people in the garden. Sort of frightening because they are really huge.
Below is information on these wasps from Joe Boggs, a bug expert from Ohio State. For more info go to his post at Ron Wilson. As Joe Boggs states, these insects are impressive and I agree.

KILLERS ON THE LOOSE!  During a visit on Wednesday to Glenwood Gardens, a Hamilton County Park District park located north of Cincinnati, I observed one of the most impressive populations of cicada killer wasps (Sphecius speciosus) that I've ever seen in my entire career!  These giant wasps are the largest wasps found in Ohio, measuring 1 1/8" - 1 5/8" in length.  They are the nemesis of cicadas, particularly the annual dog-day cicadas (Tibicen spp.), so they are considered beneficial.  However, their low-level flights over sand volleyball courts, lawns, and bare areas in landscapes can be disconcerting.  Of course, if you know what's actually going on, fascination can replace fear when you look upon these impressive wasps.

First, remember that as with all bees and wasps, only the females possess stingers (ovipositors = egg depositors).  Second, unlike many of our other wasps, female cicada killers are notably non-aggressive.  You really have to work hard to make them sting!  The females spend their time digging and provisioning burrows with paralyzed cicada-prey.  Their attack on a cicada is signaled by an abrupt halt in the staccato "singing" of the cicada, often punctuated by a high-pitched screech, which usually means a cicada killer has committed an insecticidal act.

The males spend their time establishing and defending territories that encompass females.  Biologists call such collections of males gathering for the purpose of competitive mating "leks".  The males will aggressively buzz any transgressor who dares to enter their lek; including people.  The females prefer to dig their brood burrows in bare, well-drained soil that is exposed to full sunlight.  Although the wasps are considered solitary, all of the females have the same nesting requirements.  Thus, it is not unusual for there to be numerous burrows, and wasps, in relatively small areas.  The males are notoriously territorial and will chase after other males as well as picnickers, golfers, volleyball enthusiasts, and gardeners.  Fortunately, it's all a rouse since the males lack stingers.

Cultural practices that promote a thick growth of turfgrass will usually eliminate a cicada killer infestation in a lawn in one or two seasons.  In landscapes, the wasps prefer loose soil in full sun; however, they will occasionally set-up shop in open areas that are covered by a thin layer of mulch.  Deeping the mulch layer and periodical raking to disturb the mulch or adding plants to shade the soil will make conditions less favorable for the wasps.  Since this is a beneficial insect, there are no insecticide recommendations specific to controlling these wasps.  Education is one of the best approaches to reducing the angst sometimes caused by these wasps.  Indeed, Glenwood Gardens have a nice sign posted next to one of their cicada killer colonies located in a high-traffic area to educate the public on what's really going on with these bio-allies.


  1. Crikey! I haven't seen any of them YET! (shuddering)

    1. I had never even heard of them before until this year. I just got back from weeding and I did see one female. Her stinger is at about 1/4 of an inch long, and they have a very loud buzz--can't miss that buzz. You should see them fly through the air carrying a cicada.

  2. Thanks for great information you write it very clean. I am very lucky to get this tips from you

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