Thursday, July 14, 2011

To Kill A Cicada Killer (Wasp)

Let me begin with a statement that I am not normally a garden pest killer. I prefer to get rid of the pests' attraction to my yard as the method of elimination. That has proven to be the most successful solution over time. However, this instance wasn't that easy.

Several years ago, we noticed a nest of Cicada Killer Wasps in our yard. I wasn't too alarmed because my research had revealed that these ground dwelling insects were relatively harmless and almost certain not to sting under any circumstance. That didn't make the wasp any less intimidating though. With a length of over two inches, menacing coloration, and active swarming, they can put the scare in just about anyone.

The good news is that the wasps have a relative short life-span and are only around for a few weeks a year at the end of July / beginning of August. They propagate by laying their eggs into the bodies of Cicadas that they capture and kill, so you are most likely to see them during the same time that Cicadas are present. Since the wasps are attracted by Cicadas and the favorable soil conditions of our yard, there was no way of making this site less attractive to them (i.e. We weren't willing to cover the yard in several inches of mulch or attempt to eliminate the Cicadas!).

The bad news is that they apparently found the conditions our yard favorable for nesting and over the course of a several years had multiplied to a good-sized colony. This year dozens of nests appeared throughout the yard; we decided that something had to be done about them.

I found several commercial insecticides that would do the trick, but we were concerned about using these types of toxic chemicals around our family's pets.

We read about physically killing them... literally swatting them out of the air with a tennis racquet and smashing them by foot. Uh. No thank you.

One home brew method captured our attention. It required the application of household ammonia into the underground nest; something that would be harmless to our pets in the manner in which it would be used. It would also be a relatively inexpensive solution compared to the costly commercial insecticide sprays and powders. We decided that it was worth a try.

The idea is to identify the Cicada Killer Wasp nests during the day while the insects are active. That was easy. The wasps actively swarm low to the ground and emerge from the soil from a distinctive hole (about 1/2 inch in diameter) with a pile of excavated earth beneath the entrance to the underground nest. We flagged each of these nests with a colorful plastic knife; something that would be easy to see under low-light conditions.

Later that day, in the evening when temperatures had dropped and the wasps were back to their nests and inactive, we returned with our materials. We came armed with a flashlight, small funnel and a bottle of household ammonia (scented is okay). At each nest, we inserted the funnel and poured about one (1) to two (2) cups of ammonia into the hole. Then upon removing the funnel, we covered the entrance hole with some of the excavated soil and tamped it firmly in place. This process was repeated at each nest location identified earlier in the day.

There are a number of wasp nests in our yard, and since the larvae don't all hatch on the same date the inhabitants continue to emerge over time. That means there have been new nests appearing almost each day. However, all of the nests that we have treated with our solution have remained sealed and inactive. Success!

We fully expect that we will need to repeat this process again for the next few years before we completely rid our yard of these pests, but based upon our effort to-date, the solution has worked. There is a noticeably smaller infestation of the Cicada Killer Wasps in our yard then what there has been over the past few years. Hopefully, this process will work for you as well.


50 comments:

  1. hope this works! bought ammonia this afternoon, nests are marked...waiting a little longer to pour it down! last smmer I tried the tennis racquet route...

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  2. Out of dozens of nests treated this year (Yes, we have an infestation!), only one was reopened in the morning. That said, I fully expect to need to repeat this treatment for a year or two before all of the wasps are eradicated. Good luck!

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  3. Last year we had a few nests pop up and I wasn't really sure how to treat them, so I just washed them away. This year we have a pretty bad infestation. I have tried amonia and none of them have been reopened. I have also tried boiling water which is less effective if the female isn't in the nest and a couple of those were re-opened. Everytime I pour the ammonia/water down the hole, I listen for the buzzing noise of the female, that way I am hopefully killing some of the eggs along with keeping her from digging another nest. It wouldn't be so bad if there weren't tons of the males flying around near my deck during the day. I certainly hope the ammonia works and we see less of them next summer!

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  4. I'm the first commenter from above...so an update:
    Ammonia seems to work as no nests have reopened (I listen for the buzz as well). But more keep coming. So I'm filling holes almost every night. I also decided to swing away with a badminton racket. Took out about 15 in 45 mins and enjoyed that! As of this afternoon I only saw 4 flying with 4 new holes. Was out of ammonia so used boiling water tonight. Heard the buzzing on 3 out of 4 so I hope they are gonners too! We'll see tomorrow but more importantly in the weeks to come and next season if I've had much of a long term impact or not. The key for me in the short term is clearing them out by my daughters 5th bday party in moe august which is at the house (killers in the front an party in the back though).

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  5. Anonymous: Good point about new nests appearing, as the wasps don't all emerge at the very same time. I had to treat new nests for about two weeks. However, all of the treated nests stayed vacant. We will be able to gauge the true results this time next year!

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  6. Hello,

    Terminex just left, but I don't feel confident. In fact, one of them just killed and left a Cicada on my patio?? I could not help but take a pic. At least 3 are swarming around now and I am petrified! Will monitor them and use your methods over the next two days. Will keep you posted.

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  7. We have had this problem for several years and have not gotten the best of it. I am trying scattering a diatomaceous earth bug mixture around the mound and poured ammonia down the hole and then put a stick in the hole. I don't think I poured enough ammonia as they are back this morning but I will pour a couple of cups of ammonia tonight. I am not too afraid of these wasps as only the female stings I am told. The males do not (I am told). When they take over it looks like hundreds of mounds but I am determined to get the best of them!

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  8. I too have had these wasps for several years. The good news- my children are no longer afraid of them. They have nests on our property and on my neighbor's property. I am concerned about the effect of the ammonia on the grass and on my neighbor's vegetables.Any comments?

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  9. Anonymous (07/01/2012) - The ammonia is applied directly into the wasps' nest entrance using a funnel (i.e. under the surface of the grass), and the volume is relatively small (i.e. one to two cups per application), so unless you accidentally spill the container of ammonia on your lawn, there should not be any impact to the grass itself. I have not noticed an adverse reaction, and I do not see how the spot-use in your yard could possibly harm a neighbor's vegetable garden.

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  10. I have see two of these this year. I have one that is on my patio every morning. It is a concret patio so after doing some research I think it's a male and that there must be a nest near by. However I can find no sunch evidence of a nest... any idea how near near by is? Are we talking a couple feet or anywhere in my yard?

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    1. It's my experience that the wasps don't venture terribly far from home, so the nest should be nearby.

      The nest is typically very obvious... a small mound of freshly dug dirt (i.e. 2 to 3 inches tall and 6 inches in diameter). It may be under a bush, or amongst the flowers; it's not always in plain sight in the middle of the yard.

      You may want to try to follow a wasp to see if it will lead you back to the nest.

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    2. I applied this method last night using houshold (lemon scented)ammonia. I marked approx 30 plus nests. I used a funnel on most of the nests. There were at least three nests that producted buzzing and a wasp trying to exit. when pouring in the the holes under my front porch I listened as it sounds like the ammonia ran right into a large cavern! I was hoping for some immediate results in this area. but I also have some under some bushes near the front port. This morning there were a half dozen buzzing around the porch. I am prepared to salt the earth tonight. Hopefully they will at least leave and dig in the yard where I can get at them.

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  11. I have had these things for a few years now my husband thinks they are neat?Like all of you they have taken over the parking spaces.People do not want to come to our house to visit because of these annoying things!I have read all the information on them so fingers crossed without him knowing I hope to rid us of these things!!

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  12. This is the third year I have been dealing with the cicada killers! My exterminator has tried the dusting technique in and around the entrance to the hole without any success. I just tried pouring boiling water down the holes this evening. I'm trying the amonia technique tomorrow night. Hopefully this will get rid of them. They are a menace and make me fearful with my daughter playing in the yard. I will continue to post with my progress.

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  13. We have tried the ammonia with a spray bottle to really get down in the hole and then I have used a long stick to cover the hole with dirt. These holes they dig are pretty deep so I used the stick to jab down the hole to make sure nothing else was in there. Hopefully this will help. Have been doing the ammonia thing for 4 nights now. Just stared covering the holes tonight. We have also tried wetting the nests throughout the day to deter them. I have killed one or two this way as well.

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  14. Thank you for this info. This is the first year I have noticed cicada killers in my yard. It is interesting to note that the nests I have found are in my front flower beds while the cicadas are in my backyard (I have no trees in front). I have killed about a dozen of these by swatting them with a flyswatter and then bashing them with a brick. I have only found a couple of nests and am going to try the ammonia tonight. I do not want to get to a point where people are afraid to come visit or the mail carrier won't deliver for fear of being stung.

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  15. I read one person used a unique approach. They mixed a quantity of 1 part cooking oil to one part vinegar then shook it up and shot it in the holes with a squirt bottle. I thought it sounded rather weird but I didn't like dumping toxic chemicals and insecticides down into the ground. So I tried it. I squirted the stuff down the hole and covered it with the excavated dirt. Low and behold not one hole was reopened. I'm not sure the theory or if it kills larvae....all I know is none of the holes have been reopened and my population seems to be dwindling. They apparently left for somebody else's yard.

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  16. my cicada bees are in my flower beds by my front porch, my husband wants to use gasoline! I've tried the powder insecticide without success. Two questions... will the amonia kill my flowers (I'm guessing yes) second will it prevent future plantings from growing?

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    1. The ammonia will only affect plants that it comes into contact with (i.e. if you spill it on your grass). If you use the funnel to carefully direct the ammonia into the hole, there should not be a problem. You are only using a cup or two per hole, so the chance that it could have any lasting affect on your yard or garden is very remote.

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  17. I am in the third year of battling the cicada killers. Last year (year 2) I declared war. I stalked them, killed them with a tennis racquet, and poured boiling water down every active nest at night. It's early, but the population seems smaller this year and I found my first and only nest today, two weeks after they started emerging. The boiling water is effective at nabbing the female (the bzzzz confirms it) and possibly killing the larvae, but it is labor intensive. Going to try vinegar and see what that does. I may try ammonia as well, but I'm not wild about putting it in the yard, even with a funnel. I don't think we'll ever totally get rid of them, but my goal is to keep it manageable so my kids can play in the yard.

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    1. The ammonia will only affect plants that it comes into contact with (i.e. if you spill it on your grass). If you use the funnel to carefully direct the ammonia into the hole, there should not be a problem. You are only using a cup or two per hole, so the chance that it could have any lasting affect on your yard or garden is very remote.

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  18. well I just moved to kansas and didnt know what the big wasp was and now I know and it has been two years now.. last year I just comvered the hole didnt work.. will try the ammonia as Ihave more this year and they are in my flower bed near my front door..I killed one by catching in a butterfly net and thought that was the only one but lo and behold today there are 2 more holes..so I will try the ammonia.

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  19. maybe I put the ammonia in too soon.. if I see a hole dug how long to wait till egg is in there and the female is feeding. I have a new hole this a.m. the ones in the flower bed are gone for now I saw a bigger wasp this a.m. and now a new hole backto store for more ammonia but should I wait a day or two?

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    1. I don't believe that you can put the ammonia in too early. I have always used this process as soon as I spot the nest hole. After treating dozens (!) of nests last summer, there have only been two so far this season. Score!

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  20. I have cicada killers as well, but I cannot get to the nests. The dirt has eroded under the concrete steps that lead up to my home and that is where they live. I know this because I see them emerging and returning through a small crack. I suppose I can try filling up the space with dirt and sealing the crack. I think I also have them under my porch, but again can't get to them without ripping off the siding. I'm not sure what to do there. Any advice?

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  21. Last year, I tried to live peacefully with these guys since they don't really sting and kill grasshoppers, etc. But they came back in droves this year!!! Unfortunately they are all in my above ground garden, so I don;t think pouring a gallon or two into my vegetable/fruit garden will work. In the meantime collecting herbs, tomatoes and cucumbers etc. is terrifying...you get "buzzed" by 20+ angry looking bugs protecting their nests. Maybe I'll try the boiling water...but that might also kill all the plant roots. Any other veggie friendly ideas?

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    1. jennibean - I can tell you that the ammonia is very effective at eliminating these wasps. From the dozens of nests I treated last summer, there has only been two that returned this year. And there has been no damage or ill-effect to my lawn, shrubs, or flowers that were near the treated nests. The wasps tunnel deep, and you are only using a cup or two of ammonia per nest. I really don't see this being dangerous in your garden; certainly nothing like the chemical pesticides, herbicides, and fertilizers that are commonly used without a second thought. Good luck!

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  22. I tried the Dawn dish detergent first..it is supposed to remove essential oils of the head and wings and suffocate them...didn't seem to work. Then we did the ammonia and blocked the holes with rocks...I no longer see any holes but am over run with the wasps! All the nests I blocked were in the dirt path that out behind my yard. They don't appear to have reopened. I read they don't like to nest so much in grass...so why do we still have so many???

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  23. Elle - I have not heard of the dishwashing detergent method. Seems difficult to me. Be certain that you are performing the ammonia process at night when the wasps have retired to their nests for the day. Otherwise, they are flying about and will likely create new nests. It's my understanding that the wasps do not care for tall grass (i.e. in an unmowed area), which is why they are often found in a well-kept yard where the grass is short. And while you may have treated all of the nests in your yard, there may be others in neighboring yards or adjacent areas, which may be the wasps that you see flying about.

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    1. We bought a really long funnel and marked all the holes and poured two cups or more in each nest at night but the activity during the day is so intense it's hard to be in the yard. I was wondering if you knew if the ammonia gets to the larvae in the cicada bug down in the chamber and if blocking the holes prevents them re-emgerging the next year?

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    2. Elle - I treated dozens (DOZENS!) of nests in this manner last year, and I've only seen a couple return this year. I believe that the ammonia works VERY effectively.

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  24. We have had these wasps for years but they have become unbearable this summer. We have had a drought so I'm assuming that's why they are so bad. We have at least 100 nests in our 1 acre backyard. My husband has killed about 100 of them with a racket but they are still everywhere! We are going to try the ammonia this weekend. I have a few questions though. Our yard is mostly sandy soil. Will the ammonia drain down into the hole with it being so sandy? I fear that it won't make it all the way down the hole. We may buy a small tube to insert into the hole further. Also, we have a well system. Will the ammonia leach into the water and possibly into the well? Since we have so many nests, I'm freaked that we're putting too much ammonia into the ground! Thanks for the info and the help! I really hope this works!!!!

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    1. Anonymous - I treated dozens of nests in this manner last year, and I've only seen a couple return this year. I believe that the ammonia works very effectively.

      A tube on the end of the funnel may be helpful, but I would try treating a few nests first. The wasp tunnels seem to be very well defined, even in sandy soil.

      The process only uses a cup or two of ammonia per nest. I can't imagine that the ammonia gets more than a foot below grade. Your water well is surely a hundred feet deep or more. There is no chance that the ammonia would ever affect your drinking water.

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    2. Some people say whacking them with a racket is effective but I have two points on that 1.) They say when swatted they emit a chemical that can trigger an attack even though this is not typical behavior for them and the males don't sting at all and 2.) how does this address the the females and babies down the hole?

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  25. I have dozens of nests and the exterminator didn't help. Going to try tthe ammonia tonight ,but I have a well will the ammonia effect my drinking water?

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    1. The process only uses a cup or two of ammonia per nest. I can't imagine that the ammonia gets more than a foot below grade. Your water well is surely a hundred feet deep or more. There is no chance that the ammonia would ever affect your drinking water.

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  26. I think the cicadia killer is a neat wasp and I welcome it in my yard! Beats putting out the poison! They are beneficial creatures in my book. Cicadias are noisy and destructive and this wasp can handle them in such a fascinating way!

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  27. Sevendust works pretty well but I've found that on some nests, you really need multiple treatments. These things are really a pain to get rid of. If you plant grass seed, it will definatly help as they really can't live in thick grass. They always look for bare spots in lawns or sandy areas

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  28. Hi I also have the wasps. Has anyone called a pest control? I will try the ammonia. The only wasps I have seen are the females. I killed one today. But I have bad reactions to bee bites. So I am very scared of these wasps. I want everyone of them dead......

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  29. Having been at war with these things for three years, I really lost my patience when I saw a female go after one of my hummingbirds. That's it! I have so many nests that I decided to try this tactic. I roll up a paper towel like a cigar and saturate it in a solution of garlic powder and Ammonia and shove it down the nest with a long steak. Last night I spread Bugbegone on the lawn and today I bought Spectracide Triazicide and will use that later tonight. I will keep up this battle until they or I am gone!!

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    1. Game on! These things are getting out of control. Hope it's not too late in the summer but holes are still there. Ammonia first and if this doesn't work I plan on buying chemicals.

      Ken - really, only 2-3 cups in these deep holes?

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    2. Anonymous - Yes! You only need a couple of cups per hole. The most important thing is to wait until night when all of the wasps have returned to their nest. If you treat the nests during the day, you are wasting the effort as their homes are empty. Mark the locations so you can easily find the holes at night and pour in the ammonia. If the nest is still active, you will hear the wasps buzzing about. Cover the hole and that will be the end of it! Good luck.

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  30. Thanks Ken! Anonymous again (call me Anonymous Q).

    I will keep you posted with the results. I have close to a 100 holes now. Each year more holes appear so it's time to do something about this. I noticed the males are gone but the females are still at work. The "plan of attack" is this Thursday around 10pm. I have 8 gallons of ammonia, a funnel and I'm going to set-up some outdoor lighting. Question for ya...do you think it's necessary to attach a hose to the funnel so that most of the ammonia doesn’t absorb into the soil? Those holes look deep! What are they…a foot or so deep, right?

    So, you are Cicada free? None came back the following year?

    If this works, I owe you BIG TIME! Your advice is awesome!!!

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    1. Anonymous Q - I'll be anxious to hear how your treatment goes. While the nest tunnel may be long and deep, we never used a hose on the end of the funnel. And I could tell that the ammonia application was still very effective because we could hear the wasps buzzing loudly after pouring in the liquid.

      After treating many dozens of nests last summer, I have only seen a couple of new ones this year. There has been no ill effect on the lawn, shrubs, or garden plants. And our pets were not hurt by the application of harmful chemicals. I would say that was a huge success!

      Good luck!

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  31. What about treating the nest after the adults have died off for the winter. For me, that will only be in about two weeks. Would the ammonia kill the wasp larvae that is in the nest? I am too afraid of these things to tackle them even at night.

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    1. Anonymous - I cannot speak to the effectiveness of the ammonia killing the larvae after the adult wasps have died naturally.

      While I can understand your fear of these insects, I can assure you that we had absolutely no problem treating the nests in the evening once the wasps have "retired" for the night. We would pour in the ammonia and quickly cover the tunnel opening with some of the loose dirt from the wasps' excavation. Not once did a wasp attempt to emerge from the hole and harm us.

      You can do it!

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  32. I've tried the amonia...went thru 2 gallons, killed my flowers but not the bees...they simply make new tunnels! Any other ideas? I went to a farm and fleet store and clerk sold me a dust that is made for attracting/killing biting flies. She said many customers have had success using this on the cicada bees. However after reading the label didn't use...it says that it's harmful to small animals! Any other ideas? They are pretty much done for the season...are there nests that can be dug up?

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    1. Anonymous - Sorry to hear that you had this trouble. I can only vouch for my own situation. When applied as I instructed (i.e. at night, with a funnel directly into the tunnel) I had a literal 100 percent kill rate and absolutely zero damage to grass, flowers, or shrubs. Out of many dozens of nests last summer, I have only seen two this year. Bottom line; it worked for me and many other people.

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  33. Dear God...

    I saw one of these suckers yesterday dragging a cicada up our driveway and into a hole the size of a marble just beside it. My husband had just mowed, trimmed and edged our lawn, and this critter built its nest where he'd edged. I saw a mound of dirt right beside it. Only one I've ever seen. Now my husband's back in S. Carolina working (we live in Louisville, KY) and I'm here alone to battle this thing. Best part? I'm allergic to bees! Next best part? We're getting ready to list our home in about a week (being transferred to S. Carolina). Lovely little extra to have while showing our home, huh?! Our lawn is beautiful, thick, lush and weed-free, but that doesn't matter if we've got ginormous flying insects coming out of the ground, does it?

    Cannot go near the nest for fear I'll get stung (could kill me). Will Terminex/other be able to help me at all? Any other solutions? It appears I only have one right now...

    Thanks so much for your help ; )

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    1. Ellie - Have no fear! You can do it yourself. Just wait for evening (i.e. after dark). The wasps are inactive at that hour and are snugly inside of their nest. Pour in a cup or two of the ammonia using a funnel (so you won't harm your grass) and use the excavated dirt to cover the hole.

      If you are really that fearful of being near the nest, enlist the help of a neighbor or friend. Terminex / Other are going to charge you a small fortune and since they don't treat the nest at night, they won't actually solve your problem (i.e. the wasps will be out and about during the day).

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