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:
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.
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]https://www.epa.gov/pesticide-labels/label-review-training-module-1-label-basics-page-26
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.
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.