I need to forge an opinion on BTI (an insecticide)

In My Humble Opinion
1

I live in a wooded area of my village. There are LOTS of mosquitoes in this forest. As in, you can’t stay outdoors without moving for more than 2 minutes without a sting. The rest of the village is not affected, it’s mostly just this forest, with maybe 40 houses.

From what I understand, BTI is a product based on a bacterium that attacks mosquito larvae and makes them unable to absorb food, so they starve to death before becoming adults.

Two years ago, the village council sent us a survey proposing a trial dispersal of BTI in our forest. I think some people in the forest had asked the village to do this. The proposal : we’d pay about 100$ per house in the sector for the trial, which was about 1/3 of the real cost (the village would pay the difference), but everybody in the forest would have to pay. We said yes, eventually a majority said yes, some neighbours (including “Fred”) set up signs claiming they didn’t want the thing on their property and they wouldn’t pay. From a conversation with “Fred”, it seemed mostly about the money and about city folks moving in and not appreciating the rural life (he’s not rural by any means). (AFAIK eventually everybody paid up because there is no legal way to withhold a charge on municipal taxes without losing your house.)

It didn’t work well the first year, we had as many mosquitoes as before, but it was a weird year weather-wise, so there was another survey for another trial year. And it worked well in 2020, which was good because we certainly needed to be outdoors.

So last Fall there was a survey about implementing “for real” in 2021. We’d pay the full cost this time. This passed by a slim margin.

For the record, our household voted Yes all three times.

So “Fred” has been going around and distributing leaflets about how this is not good, etc. The leaflets are from an ecological organisation in Québec.

I was expecting the usual drivel about how this will kill your children and make your tomatoes radioactive, etc. And yes, there was something about “we don’t know what those additives are!!”. But I found some of the arguments interesting.

They claim that BTI actually kills some other small insects at the same time as mosquitoes, so that, in areas where BTI is used on a large scale, eventually the bats and the birds have much less to eat and their population dries up.

They also claim that BTI is mostly promoted and defended in the scientific literature by one scientist in Europe… who happens to have a direct financial interest in the company distributing BTI.

So what should I think about this ? Am I killing birds here ? Does it make a difference that BTI is only used in this little forest in a village that’s about 10 km by 10 km of agricultural fields ?

2

  1. Diminishing food sources is true, however, Bti toxins affect only mosquito, gnats and blackfly larvae. A more organic approach is to encourage birds and bats in your woodland, and to clean up stagnant water to the extent possible.

  2. I’m not sure who this European scientist is, but there have been NIH funded studies, and NIH has a stringent financial conflict of interest disclosure program.

  3. I would be curious if there is something about this particular stretch of woods that’s extra appealing to mosquitoes. Is it swampy? Is it used as a dump, so has old plastic paddling pools half filled with stagnant water? If not, and you have the normal (annoying) level of mosquito activity that happens in any woodland in a non-arid climate, Bti is a viable solution. My personal preference is to try all non-insecticidal treatments first, but I know that’s not always possible with a municipality. That said, Bti is probably the safest means of applied control within a residential area, especially in areas where mosquito borne disease is an issue.

3

I am in Central Texas we have floods where the soil is saturated and received up 12 inches rain in 3 days and then more. My low areas are 27ft ×15ft and about 1ft to 1/2 ft deep.

Bacillus thuringiensis subspecies israelensis. (B.t.i.). It’s a natural bacteria found in soil. In Texas their called Dunks. I have goats, deer, cats, dogs, chickens, ducks and honey bees. Also there are falcons, eagles, bats, monarch butterflies, owls snakes. We’re on the migratory path for snowey egrets and on and on. I put them where the ac drains. I add them to the big tank the cattle and other livestock drink. All of the ranchers and everyone uses BTI. There isnt anything starving around here. Execellent product.

When I lived in Mexico the health department came by monthlyand dropped it in the cisterns. It was provided at no cost to the villiages. More options for you to peruse:

Study World Health Organization

https://www.who.int/water_sanitation_health/gdwqrevision/RevisedFourthEditionBacillusthuringiensis_Bti_July272009_2.pdf

Pub Med

ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborator
https://www.researchgate.net/publication/303190570_Using_the_bio-insecticide_Bacillus_thuringiensis_israelensis_in_mosquito_control

4

Thank you both for your replies. I got another propaganda visit from “Fred” yesterday, this time the subject was really money.

The forest has maybe 10% evergreens and is somewhat swampy for much of the spring, up until early June. The wet areas couldn’t conveniently be drained I think, and AFAICT are not on any house’s lot (part of the forest is attached to the field beyond it, which belongs to some distant farmer).

5

I would be concerned about mosquitos developing resistance after applying the same pesticide to the same place for several years in a row.

Let’s say that Bt is 95% effective against mosquitos. That leaves five percent who are resistant. Those are the five percent who are left alive to breed. After a few generations of this, your woods have an entire population of Bt resistant mosquitos and nothing to control them.

Now if the mosquitos are carrying disease I’d be all for the use of Bt for a couple of years to reduce the population. But not year after year in the same spot.