Tag Archives: ATSB

Spartan Mosquito Pro Tech in tree

Does the Spartan Mosquito Pro Tech attract mosquitoes?

There are currently eight devices on the market that claim to lure and kill mosquitoes with fermenting sugar solutions, but only one, the Spartan Mosquito Pro Tech, is registered with the Environmental Protection Agency. That registration is required because the active ingredient, boric acid, is a regulated pesticide. As a result, claims made by Spartan Mosquito about the device cannot be false or misleading.

This post is about one those claims: “mosquitoes will gather around the tubes”. The claim is made on the device’s label (below), on the instruction sheet (below), on the company’s website, and in the EPA registration document, where it’s mentioned five times.

It is, of course, a claim that is central to how the device is supposed to work: the mosquitoes in a yard are somehow drawn to the contents of the tubes, they squeeze through the holes in the cap, crawl down to the fluid, ingest some fluid, then crawl back out of the tubes. They die later from the effects of boric acid. It’s an elaborate sequence of events.

What causes the mosquitoes to gather?

Unfortunately, nowhere does Spartan Mosquito explain exactly why the Pro Tech would cause mosquitoes to gather. But the company says the device is the “next generation” of the Spartan Mosquito Eradicator, and for that device the company claims mosquitoes are attracted to the carbon dioxide produced by sugar and yeast inside the tube. Although sugar and yeast are not specifically listed as ingredients for the Pro Tech, the contents appear to be sugar and yeast.

Evaluating the claim

The easiest way to determine whether mosquitoes gather around the Spartan Mosquito Pro Tech is to just look. I’ve deployed three devices (one with label removed) in my yard this summer and, to date, I have not seen any mosquitoes near the devices. There are also no mosquitoes inside the devices. For the record, I know what mosquitoes look like and have thousands in my yard.

The above technique has two problems, however. The first is that one has to be close to the devices to observe mosquitoes, and it’s theoretically possible that the instant a human approaches, the mosquitoes abandon the device and seek out the human, instead. I don’t actually think this is a real concern because I can recognize a mosquito from quite far away, plus I can use binoculars so that the distance is even greater. The second problem is that people might not believe me when I say I observed zero mosquitoes gathered around the tubes — people are just far more inclined to believe the label’s claim.

To address both of these concerns, I decided to use a security camera to record the area around a Pro Tech. Then I could examine the footage and make it publicly available to those who might be skeptical. 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 I set it up (September 2nd, 2020) I counted over a dozen mosquitoes (all Aedes albopictus) 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

To satisfy potential critics, however, I collected footage for over a week, ending observations on September 10th. The mosquitoes were still plentiful on the day I published this post (September 12th), so there were plenty of mosquitoes in my yard for a fair test.


During 183 hours of footage, I couldn’t find a single mosquito on or near the device.

It’s theoretically possible that a mosquito landed on the far side of the tube (which I couldn’t view) and I missed it, but I think I can safely conclude that large numbers of mosquitoes did not “gather”, as per the labelling claim. I’ve also continued to observe the footage beyond the 183 hours, but it seemed like a waste of time to continue. The device was simply not attracting mosquitoes. There’s only so much boredom I can endure.


If the Spartan Mosquito Pro Tech does not attract mosquitoes, at all, I’m left confused. Is it possible the EPA didn’t require Spartan Mosquito to provide experimental proof for this label claim? I see three explanations.

First, I’m wondering whether the EPA viewed the claim as “advisory” language:

“Advisory statements are intended to be informational. They provide information to the product user on such topics as product characteristics and how to reduce risk and maximize efficacy while using the product. Such statements are acceptable as long as they do not conflict with mandatory statements, and are not false or misleading, or otherwise violate statutory or regulatory provisions.” [bolding added]


I.e., maybe the EPA reviewer deemed the “mosquitoes will gather” statement as somehow separate from the core efficacy claim (“kills mosquitoes”) and thus didn’t request proof. Regardless, the last part of the above passage still requires that such advisory statements are not false or misleading.

Second, perhaps the “mosquitoes will gather” claim is based on data from a cage experiment conducted inside a laboratory? I.e., if large numbers of mosquitoes are trapped in a container with a Spartan Mosquito Pro Tech, maybe they do gather around the device simply because there’s nothing else for mosquitoes to land on. If that’s the case, however, it would seem highly misleading to imply (on all the labelling) to consumers that mosquitoes will gather around the tubes when they are deployed outside. 100% of the marketing suggests that the device attracts mosquitoes in yards.

Third, if the data supplied to the EPA was, in fact, from an outdoor experiment, maybe it’s just untrustworthy. I.e., from an experiment that didn’t have controls or that lacked meaningful replication. Or cherry-picked from multiple experiments where all but one showed no effect. There are lots of way to conduct a bad experiment and to pitch the results as somehow fantastic. I’ve heard this was (and is) an issue for the Eradicator.

EXTRA: What about the “kills mosquitoes” claim?

To gain approval for its label claim, Spartan Mosquito must have supplied some sort of data to the EPA that confirmed the device could kill mosquitoes. But if the device doesn’t attract mosquitoes present in a yard, how could it possibly kill them?? I’m speculating here, but if Spartan Mosquito did, indeed, test the devices inside cages, they might get a positive finding. That’s because the devices contain an aqueous solution of boric acid (approximate 0.17%, I think), and thus one would expect some boric acid to be present in the fumes that escape through the holes in the cap. Those fumes could conceivably poison the mosquitoes trapped in the cage. The lethality of the fumes might be extremely low, but I’d wager the effect would be measurable when compared to a control cage that lacked those toxic fumes.

Does boric acid evaporate? Yes, the main source of boron in the atmosphere is due to evaporation of boric acid from oceans (Park and Schlesinger 2002). More generally, evaporation of acids from aqueous solutions can even be used to retard bacterial and fungal growth of meat.

It would be interesting know what Spartan Mosquito (or the researcher it hired) used as the experimental control treatment. One way to bias the experiments in favor of finding an effect is to simply use empty or water-only tubes as controls. This is because fermentation itself causes acids to form, and those acids would be expected to enter the vapor phase and permeate the experimental cages. That’s in addition to the ethanol that enters the vapor phase, of course. I.e., mosquitoes trapped with a tube of fermenting sugar might have low survivorship because they were bathed in vapors that are mildly deleterious. Again, such an effect would have nothing to do with mosquitoes squeezing through the holes and ingesting poison. And, of course, the “vapors killing the mosquitoes” effect wouldn’t work at all when tubes are deployed in a yard.

If Spartan Mosquito did, in fact, test the device in cages, it would seem best to constrain its claims to “causes mosquitoes in cages to gather” and “kills mosquitoes in cages”. Then if consumers had a problem a mosquito outbreak in their cages, perhaps the Pro Tech would be an attractive option.

EPA guidelines

I was curious so I dug around in the guidelines to see what type of experiments need to be done to establish efficacy. Here’s a screenshot from, “Product Performance Test Guidelines OPPTS 810.3000 — General Considerations for Efficacy of Invertebrate Control Agents“, that seems relevant:

The wording in the red-boxed sections suggests that the EPA allows laboratory experiments in place of experiments under actual conditions (outside). I couldn’t find any directive from the EPA that required a company to clarify the conditions under which the efficacy data were collected.

Again, I don’t have any information on what type of experiment Spartan Mosquito conducted. The above is just to indicate that it may be possible that they didn’t conduct the test outdoors.

What does Spartan Mosquito say?

In general, when consumers ask the company on Facebook how the device works, the company directs them to this webpage or this Facebook video. Neither has information on how the device works or how well it works. The company simply deletes any question it does not want to answer, and often blocks skeptical users who ask probing questions. If you doubt me, try asking a scientific question on the company’s Facebook page. For example, “What causes mosquitoes to gather around the tubes?” Or try, “Do you have any videos of mosquitoes gathering around the tubes when device is deployed in a yard?” I’d also like to see them answer, “Under what conditions was the Pro Tech tested?”

The only details the company provides about efficacy is that device kills 95% of mosquitoes.

Which is hard to believe.


Below is the video, separated into 16 segments due to size limits on YouTube.


Experiment shows Spartan Mosquito Eradicator do not work

Experiments on Spartan Mosquito Eradicators fail to detect efficacy

According to research conducted in Florida, there’s no evidence that Spartan Mosquito Eradicators kill mosquitoes. Here’s the citation:

Aryaprema, V.S., E. Zeszutko, C. Cunningham, E.I.M. Khater, and R.-D. Xue. 2020. Efficacy of commercial toxic sugar bait station (ATSB) against Aedes albopictus. J. Florida Mosquito Control Association 67: 80-83. PDF

I summarize the two experiments and explore some of the implications, below.

Laboratory experiment

Below is a rough reconstruction of the laboratory experiment they conducted. In each of the cages (BugDorm-2120), 100 male and 100 female tiger mosquitoes (Aedes albopictus) were released, then monitored for mortality at 24, 48, and 72 hours.

Schematic of laboratory experiment based on description in Aryaprema et al. 2020.

Below are the cumulative mortality data for the three cages. Result: the Spartan Mosquito Eradicator filled with the provided packet ingredients (treatment) did not result in higher mortality. I.e., there was no evidence the device killed mosquitoes under laboratory conditions.

Field experiment

The researchers also conducted a field experiment using two sites that had large populations of tiger mosquitoes (because of the presence of tires). At each site they deployed five tubes (separated by 4 m), switching whether the tubes were “treatment” or “control” tubes every 2 weeks. A BG-Sentinel trap (without carbon dioxide) was used to quantify mosquito numbers every week.

Schematic of field experiment based on description in Aryaprema et al. 2020.

Below are the weekly numbers of mosquitoes caught in the BG Sentinel traps. Results: there was no evidence that presence of treatment tubes (filled as per company guidelines) reduced the numbers of mosquitoes at the sites.


Their overall conclusion: “Both laboratory and field components of our study show that the Spartan Mosquito Eradicator is not effective in reducing abundance of Ae. albopictus.” They speculate that the contents do not attract mosquitoes and that the holes on the device (~3 mm) are too small for mosquitoes to easily reach the fluid inside. They also highlight the need for an experiment to evaluate whether the active ingredient (1% sodium chloride) kills adult mosquitoes. I.e., even if mosquitoes were attracted to Spartan Mosquito Eradicators and could easily get inside, the salt might not be lethal. Per unpublished research, a 1% salt solution is, in fact, not lethal to adult mosquitoes.


The results of the experiments call into question the efficacy claims made by the owners of Spartan Mosquito. For example, the company says on the box that a 95% reduction in mosquitoes will occur within 15 days and will last for three months. The company also prints a graph on the label that indicates almost 99% of mosquitoes are killed by the end of this period.

Spartan Mosquito Eradicator efficacy graph

If the claims are false or misleading, which seems to be the case, states can classify the device as “misbranded” and issue stop-sell orders. Some have already done so.

These findings will also be important for the class-action suit that has been filed against the company and its owners. I.e., because there is now peer-reviewed evidence that the device does not kill mosquitoes, it will be considerably easier to prove to a jury that the company’s efficacy claims are false or misleading.

Finally, the results call into question the efficacy claims of the company’s newest product, the Spartan Mosquito Pro Tech, which replaces sodium chloride with boric acid. Although a boric acid solution can certainly be lethal if mosquitoes ingest it, the Pro Tech is based on the same design as the Eradicator and thus would not be expected to either attract mosquitoes or to allow them easy access to the fluid inside. The Pro Tech label, however, asserts that the device will attract and kill mosquitoes. It would be great to get a third-party assessment of whether those label claims are true.

Testing the Eradicator and Pro Tech at home

In regards to the question of attractiveness to mosquitoes, consumers can easily assess that at home with a zoom-equipped camera, binoculars, or a security camera. The idea is to be able to see mosquitoes near the cap (if they are there) but to be far enough away so as not to distract the mosquitoes. Ideally, capture a photograph or movie and get confirmation of what insects are actually gathering around the device (again, if any).

Per the above paper, you likely won’t see mosquitoes gathering around the devices. Per the company, mosquitoes will gather around the devices.

People can also assess whether mosquitoes are entering the devices by dumping the contents onto a white plate and taking a photograph. Ideally, share your photographs on Spartan Mosquito’s Facebook page — they’d love to see them. Or post on them on Twitter and cc me (@colinpurrington).

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.


  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.