Killing mosquitoes with autocidal gravid ovitraps

In case you are looking for a way to kill mosquitoes without sprays, here are three types of traps that kill pregnant (gravid) mosquitoes that are searching for water in which to oviposit. Each is filled with water and decomposing plant matter (hay, compressed rabbit food, or leaves), then equipped with special lids (and sticky cards) that prevent females from escaping once they get inside. In addition to killing the females, any eggs that the female might lay are also prevented from developing by the presence of screens that trap the emerging mosquitoes from escaping. All of this happens passively, 24/7, all summer long, without the use of chemicals.

I have two from Biogents, two from BioCare (which look like these), and one that I made (instructions). They all work great but DIY one seems to catch the most mosquitoes so far.

Biogents gravid Aedes trap
Biogents Gravid Aedes Trap (GAT).
Biocare AGO
BioCare Autocidal Gravid Ovitrap (AGO).
DIY gravid ovitrap
DIY gravid ovitrap with observation window (for viewing trapped larvae).

Every homeowner should have them. Coupled with other preventative measures (eliminating stagnant water, reducing excess vegetation, etc.), you can knock back mosquito levels and enjoy your yard again. Five units is probably sufficient for an average yard but I plan on making a few more this summer just to make sure.

Ideally, everyone on your block should have them, too, so if you are planning on ordering some you should first send a note to all your neighbors to see whether you can make a bulk order. E.g., if you order a lot of Biogents you can shave a few dollars off of each unit. Buying a bunch might seem like a lot of money but compare it to the cost (~$700) of having a company like Mosquito Squad spray your yard with pyrethroids every several weeks (every year). Using these passive traps also saves all the pollinators that are killed by those pesticides.

7 thoughts on “Killing mosquitoes with autocidal gravid ovitraps

  1. Harold

    Thank your for these tips. I am very allergic to mosquitos so I have plenty of traps inside and outside my home, but will definitely take these into account.

  2. Kathy

    This is what I have been using this year. I put it in bowls all over my property and either refill as needed or redo every few weeks. It does work and says it is harmless to animals and fish. It does look gross and I saw hundreds of mosquito larvae eventually die. Summit Mosquito Bits, 30 oz. I got it from tractor supply. I even gave some to my neighbors and if everyone did this in summer it would reduce the population of these Asian mosquitoes. They attack day night not like what I grew up with they only came out at night. These new ones are tiny and aggressive.

  3. Tracy

    Hey! Cool blog! Some things you’ve wrote are pretty humorous too! I’m having a hard time finding where to buy an AGO (besides the Biogents one on amazon which is kind of pricey). Can you tell me where you purchased your SpringStar AGO trap? I also see how the Catchmaster Ovi-catch can be found on the forestry supply page but they do not sell the replacement sticky element. You’d really think it would be a lot easier to find these things. Must be “big chemical pesticide” hiding this greener and more logical option. I’m trying to supply my neighbors (who are currently using a pest company to spray their yard) better options before I go speak to them about the concerning side effects of said chemicals. Thanks!

    1. Colin Purrington Post author

      The place I’d purchased my SpringStar AGOs no longer sells them so I googled around and found the following:

      I make my own sticky cards by buying those yellow ones (e.g., on Amazon), and making partial cuts on two and then fitting them together to form an X. I like this better than what they ship with because the yellow allows me to better see the mosquitoes I’m catching (I like the instant gratification).

      Best of luck with your neighbor. My role model in all of this is a researcher at Rutgers named Dina Fonseca. For an overview of her pitch and results, see this slide show. I really like the community approach and the “take back your yard” slogan. If you have an area of town where everyone is on board with using these traps AND with getting rid of stagnant water, it can work.


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