Tag Archives: design

DIY trap to kill pregnant mosquitoes

This post contains photographs and construction tips for a killer craft I made: an autocidal gravid ovitrap. Pregnant females enter the trap, lay some eggs on or near the stagnant water within, then are prevented from exiting and die. Their progeny also die because a screen at water level prevents larvae from reaching the surface to obtain oxygen. When similar traps have been deployed they bring down mosquito levels substantially and thus are quickly becoming one of the main ways to prevent mosquito outbreaks and disease. Every homeowner should have six. They’d make wonderful gifts.

Autocidal gravid ovitrapThe design features a clear dome that helps trap the females when they are done ovipositing (they go for the light), plus a completely unneeded observation window so I can watch the larvae and pupae (fun for the whole family, plus good for demonstration purposes). It borrows general methodology from gravid Aedes traps (GATs) designed by Dr Scott Richie (James Cook University) and colleagues that recently made news on NPR (here’s an overview; here’s their paywalled journal article). I’ve designed mine to capture species that also lay egg rafts, so it’s not just a GAT. My design doesn’t use insecticide because I wanted the odor of developing larvae to be an attractant to other females (it is, by the way).

What you need

  • Autocidal gravid ovitrap2-gallon bucket
  • bucket lid
  • 6″ plastic pot
  • clear dome from cake store
  • metal coat hanger
  • plastic screening
  • stapler
  • 3 paperclips
  • small neodymium magnet
  • silicone adhesive glue
  • duck tape
  • hardware cloth
  • 1-L soda bottle
  • 1/4″ foam weatherstripping
  • black spray paint
  • Dremel tool with cutting bit
  • drill with drill bit
  • knife
  • safety glasses (when Dremeling)

Construction photographs

If you’d like to see photographs larger just click on first image and navigate like a slide show. There are many ways to construct these so if you build one and it looks completely different, don’t worry. This is because if your device is the only stagnant water around, females will use it.

I’ve only just deployed it and it’s rather cold right now so I don’t have any victims yet. But I’m optimistic and am posting now with the hope that somebody will have suggestions on how to improve the design (I’m making more). One improvement I’m definitely going to make is to drop the funnel lower into the dome so it’s harder for females to accidentally fly straight up to escape. And pro-tip if you make the above: attach the lid to pail when spray painting to avoid unwanted buildup where they attach.

I’m also posting in the off chance that a biology teacher might take an interest. Having teams make these would be really fun and then they could deploy them in the woods near the school: bonus points for team that traps the most mosquitoes. It’s fun like the classic egg-drop lab in physics except useful. Students would then take their projects home where they’d continue to be useful. Would make for a great Girl Scout Gold Award / Eagle Scout project.

Other DIY designs

For ways to kill foraging mosquitoes, please see my page, “Mosquito control tips“.

Where to buy

If all of the above sounds like way too much work you can buy traps from SpringstarBioQuip, and Ultimate Mosquito Traps. I haven’t tried any of these yet.

Useful articles

Barrera, R., A.J. Mackay, and M. Amador. 2013. A novel autocidal ovitrap for the surveillance and control of Aedes aegyptiJournal of the American Mosquito Control Association, 29:293-296.

Maciel-de-Freitas R., R.C. Peres, F. Alves, M.B. Brandolini. 2008. Mosquito traps designed to capture Aedes aegypti (Diptera: Culicidae) females: preliminary comparison of Adultrap, MosquiTRAP and backpack aspirator efficiency in a dengue-endemic area of Brazil. Mem Inst Oswaldo Cruz. 103: 602-605.

Mackay, A.J., M. Amador, and R. Barrera. 2013. An improved autocidal gravid ovitrap for the control and surveillance of Aedes aegypti. Parasites and Vectors 6:225.

Maire, A. 1985. Effect of axenic larvae on the oviposition site selection by Aedes atropalpus. J. Am. Mosq. Control Assoc. 1:320-323.

Paz-Soldan et. al. 2016 Design and testing of novel lethal ovitrap to reduce populations of Aedes mosquitoes: community-based participatory research between industry, academia and communities in Peru and Thailand. PLoS One 11:8.

Fabric conference posters

I was invited to talk about poster design in Berkeley (DOE NNSA SSGF) and DC (DOE CSGF) this past summer, and used the opportunity to test out fabric as a medium for large-format conference posters. Below are some photographs if you’re curious how logos, illustrations, and photographs look when viewed close up on fabric. By the way, I ordered the posters from PhD Posters (they mailed to my house in a tube, inside a box). And if you’re interested, my poster design tips are here (rather long-winded because I’ve maintained page since 1997).

fabric-posters

The rolled up poster above is also fabric. I didn’t have the nerve to fold it into luggage-sized square, but I’ve heard that it can be done … though crease lines an issue. Might be able to iron them out, I’ve also read.

photograph-on-fabric-poster-I

The photograph above isn’t as crisp as a glossy poster, but was totally fine for my purposes. If it really mattered, I’d just print a copy on my photo printer at 1200 dpi (or whatever) and then use double sided tape to attach. Even paper posters have fairly low photo quality, so attaching a high-resolution version is always an option when you need it.

photograph-on-fabric-poster-III

Yes, you can see the fabric if you get close enough. People standing 6 feet away wouldn’t notice and probably wouldn’t care if you told them.

illustration-on-fabric-poster-I

illustration-on-fabric-poster-II

graph-on-fabric-poster

logo-on-fabric-poster

This logo is actually from the poster that is rolled up. It’s at http://colinpurrington.com/2012/example-of-bad-scientific-poster/ if you want to see the whole poster (you can download and print for your class, if you’d like; yeah, students would just love that).

fabric-poster-edge-detailThis photograph shows how the edges can get a little frayed. Holes from pushpins are also visible. Much less annoying than the rips and gaping holes that paper gets.

Charts with bling

Just a silly pie chart I created for “Designing conference posters” to argue that graphs with illustrations can help viewers absorb results a bit faster than those with just labels and legends. (Please note that although the graphic is a tad silly, the data are real: less than 10% of Americans accept that humans evolved without supernatural help.)

Gallup poll on evolution of humans