Tag Archives: carbon dioxide

Does the Spartan Mosquito Pro Tech attract mosquitoes?

This post evaluates the claim on the label, “mosquitoes will gather near them”. Per the company, it is the first step in how the device kills mosquitoes. I.e., the device needs to attract mosquitoes if it is going to work.

mosquitoes will gather

Evaluating the claim

I used a security camera to record activity around the cap area. Here’s a photograph of how I arranged everything:

Spartan Mosquito Pro Tech with security camera

Below is a 15-second time-lapse to show that small insects such as ants were easily visible, even at night. I think they are Prenolepis imparis, which are 3-4 mm long —mosquitoes are larger and thus would be detectable even in flight.

On the day that began filming (September 2nd, 2020) I counted over a dozen mosquitoes (all Aedes albopictus) landing on my arms and legs within 30 seconds. According to the instruction sheet, the device begins to work instantly, as soon as water is added, so an hour of remote, video observation should be a sufficient amount of time to evaluate the attraction claim.

Spartan Mosquito Pro Tech begins working instantly

I collected continuous footage for over a week, ending observations on September 10th. The mosquitoes were still plentiful on that day.

Results

During 183 hours of footage, I couldn’t find a single mosquito on or near the device. Here are the contents. I also posted a photograph to iNaturalist.

Conclusion

I don’t understand how the device can kill mosquitoes.

In related news, I’m aware of three of other people who have used security cameras to assess whether mosquitoes gather around Spartan Mosquito Eradicators. None found mosquitoes.

Footage

In case anyone might be skeptical of my results, I decided to upload all 183 hours of footage onto YouTube. I had to break it into 16 segments due to size limits on YouTube.

Yeast-based mosquito control devices

If you’re even remotely interested in killing mosquitoes, you’ve probably seen ads for plastic tubes that are filled with water, sugar, and yeast. The marketing pitch is that the thousands of mosquitoes lurking in your yard will be drawn to the devices by carbon dioxide (emitted by yeast when it consumes sugar), then will all enter the device through tiny holes at the top, ingest some of the fluid inside (because mosquitoes forage for sweet liquids like nectar), squeeze back out of the tube through the same holes, and then die due to the effects of a chemical (table salt, boric acid, garlic oil, etc.) dissolved in the fluid. According to marketing claims, these tubes will completely rid your yard of mosquitoes for months.

Below are details on the eight such devices currently marketed in the United States.

Spartan Mosquito Eradicator

First sold in 2016 as the Spartan Mosquito Bomb, the company says these tubes will eradicate mosquito populations for up to 90 days. Active ingredient is table salt. Company is based in Hattiesburg, Mississippi and was founded by Jeremy Hirsch (a Which Wich? Superior Sandwiches franchisee) and Chris Bonner (works at chemical testing company).

Spartan Mosquito Eradicator

Sock-It Skeeter

Produced by the same company (AC2T, Inc.) that makes the Spartan Mosquito Eradicator. Likely also contains sodium chloride. Here is a commercial about the device.

Sock-It Skeeter

Donaldson Farms Mosquito Eliminator

Marketed to eradicate mosquitoes for 90 days. Owners say that it has “more potent attractants in the lure for the traps than Spartan”. Company is based in Chattanooga, Tennessee, and owned by Jeff Clowdus (owner of JCL Tech LED lighting) and his brother Tim.

Donaldson Farms Mosquito Eliminator

Mosquito XT

Company is based in Paragould, Arkansas, and owned by Kevin King, an insurance broker.

Mosquito XT

Spartan Mosquito Pro Tech

This device is essentially the same as the Spartan Mosquito Eradicator except that boric acid replaces table salt as the listed active ingredient. Here is a more complete comparison. Company claims it kills mosquito for 30 days.

Spartan Mosquito Pro Tech

Skeeter Eater

Company says it eradicates mosquitoes for 90 days. Distributed by Copia Products (makes baby products) in Memphis Tennessee and is owned by Wade Whitely. Manufactured in Columbia.

Skeeter Eater

Skeeter Hawk Backyard Bait Station

Label lists garlic oil (not salt) as the active ingredient. Described as “highly effective” and providing “chemical free”, “round the clock”, “full-perimeter protection”. Company is part of Alliance Sports Group based in Grand Prairie, Texas. Owned by Larry Easterwood and family.

Skeeter Hawk Backyard Bait Station

Mosquito Dynamiter

Owner claims the device will eradicate up to 95% of mosquitoes in 15 days for up to 90 days. Says mosquitoes “literally explode”. It appears to be a black version of its Wasp & Bee Sugar Trap. Made by Vic West Brands based in Austin, Texas, and owned by Nick Olynyk, an expert on junior hockey.

Grandpa Gus's Mosquito Dynamiter

Do any these devices kill mosquitoes?

Only one of the above devices (the Spartan Mosquito Eradicator) has been evaluated by scientists, and they found that the device did not work. Also, Yee et al. 2020 determined that salt does not kill adult mosquitoes.

DIY mosquito trap using a plastic soda bottle

Here are instructions for building an indoor mosquito trap using a 2-liter plastic soda bottle. All you do is add some bait (honey, fruit, juice, sugar water, or some nectar-containing flowers) and place in a dark corner of the room. It works because mosquitoes seek out sugar, which they require to fuel themselves. Once inside the bottle they can’t get out.

The above instructions are a modification of a Taiwanese science-fair project that eventually went viral. The differences between the original instructions and mine are that (1) I don’t recommend adding dry active yeast, (2) I suggest sugar sources other than granulated sugar, and (3) I don’t wrap trap in black paper. The omission of yeast is because I don’t think the generation of carbon dioxide is necessary to attract mosquitoes to sugar. In fact, adding yeast likely reduces the attractiveness and causes the trap to fail faster.

The critical part of the original instructions is to deploy the device on the floor in a corner of a room. This is because mosquitoes love to hang out in corners — they are dark and relatively free of desiccating drafts.

Tips

  1. The original instructions suggest 50 g (~1/2 cup) sugar and 200 mL (~1 cup) water but the ratio probably doesn’t matter at all. Brown sugar is likely better than granulated (white) sugar because it has more impurities (some of which are volatile). A drop of rose water might make the sugar mixture more attractive.
  2. Make traps with different types of bait to see which ones are most attractive to the species that are local. Anopheles coluzzii, for example, seems to prefer papaya and banana juice over mango juice (Nignan et al. 2020). Other species might prefer oranges. Or, perhaps, durian.
  3. Replace your bait when it stops attracting mosquitoes. Perhaps every four days if you use fruit (Meza et al. 2020).
  4. If you use flowers, opt for ones that have nectar (if you know) and are light-colored. Or stick a small potted orchid inside the bottle — their blooms last for weeks.
  5. If you happen to have a plant with extrafloral nectaries, that’s a great bait that will likely last for a long time (when you’re on vacation, for example). Try a bunch of wild cherry leaves, for example.

Why it works

Mosquitoes are famous for sucking blood, but like many insects they spend most of their lives quietly ingesting sugar from flowers and rotting fruit. For example, here are some mosquitoes nectaring in the middle of the day:

So when mosquitoes find themselves trapped inside, they will zero in on whatever you have on the countertops — fruit, puddles of syrup, cut flowers, or even a dirty sponge. I don’t have photographs of mosquitoes eating fruit inside but Justin Yoshida (Thailand) does: on jackfruit, on apple slices, and on eggplant. Mosquitoes indoors are likely not especially picky about fruit type because the option is starving to death. Mosquitoes even fall into juice containers and die, apparently, as one restaurant discovered.

In case you’re skeptical that these traps can actually work, here’s a video by somebody who followed the original (science fair) directions and killed 9-10 mosquitoes in 24 hours:

Why it won’t work outside

Don’t bother using these traps outside (the recommendation of the viral versions). Mosquitoes prefer natural sources of sugar so they will likely ignore anything inside a bottle, regardless of how delectable you think the concoction is. The exception would be if you live in a desert and there are no plants near your house.

The traps will also not work in rooms full of flowering plants or decomposing fruit. Similarly, if your kids spill juice and soda everywhere, the traps won’t work.

Adding toxins to the mix

If you have a house free of small kids and meddlesome pets, you can add bit of boric acid to the solution to create an attractive toxic sugar bait (ATSB) station. Then, when mosquitoes ingest the fluid they will die even if they manage to escape the trap (it can happen). In fact, once you have a toxin in the fluid you can and should just get rid of the funnel part of the trap — its presence is likely a barrier to some mosquitoes even though it’s relatively wide (~2 cm). Instead, cut a 3 cm hole in the side and keep the cap on the bottle. Note that because these devices are indoors you don’t need to worry about the boric acid (or whatever) poisoning the pollinators in your yard.

The above is nicely explained by Andy Lee Graham:

One perk of adding boric acid is that fermentation will likely be slowed down, extending the life of your fruit juice. Note that fermentation will occur even though you haven’t added any yeast. Fungal spores are present everywhere.

© 2020 COLIN PURRINGTON