Tag Archives: toxin

Alternative lawn signs for Mosquito Shield

Mosquito Shield is just one of dozens of companies that spray pyrethroids to kill mosquitoes. Homeowners typically pay $800 per summer for treatments spaced every 21 days and, as part of the deal, agree to feature a sign in their yard for the season.

Two types of people have these yard signs. The main category is homeowners who fully understand that pesticides have bad environmental effects but who simply don’t care. These are likely the same people who knowingly drive with their high beams on at night (“It’s safer for ME!”). And then there are people who were duped by the pesticide companies into believing pyrethroids kill only mosquitoes.

To better reach this second type of person as well as those who are interested in mosquito sprays but are still on the fence, I’ve fabricated six signs that highlight the fact that pyrethroids kill other animals:

All the signs are fairly self-explanatory except for perhaps the Bird Shield one. Pyrethroids don’t kill birds directly but many species depend on insects and spiders to feed themselves and their young. So when you hire Mosquito Shield to nuke your yard every three weeks you are reducing the numbers of birds that can survive in an area.

I realize that none of the above signs is going to be used by an actual pesticide company. Their business model is to obfuscate about the effects of pyrethroids. Indeed, most companies try to hide the fact that their mosquito sprays even contain pesticides. That’s why the government (federal and/or state) should require companies to clearly indicate the active ingredient of the spray. Here’s how it could (should) look, thus allowing curious neighbors to Google the chemical and be horrified.

Pyrethroid sign for Mosquito Shield

If you are an influential part of a local government, please consider enacting an ordinance that requires disclosure of the pesticide name on signs.

If you need an individual sign for your a presentation, here are some image files: fireflies, butterflies, bees, spiders, fish, birds.

Please share this page on your neighborhood social media to get the word out. These companies are spreading in popularity and it’s horrifying.

More details here.

Using mosquitoes’ sweet tooth to control Zika transmission

Now that everyone wants to kill mosquitoes that transmit Zika virus, can somebody please make a transgenic plant that expresses mosquitocidal Bti (Bacillus thuringiensis subsp. israelensis) toxins? Just stick the Bti gene behind a phloem-specific promoter so that the protein gets pumped into the nectar. Then when males and female mosquitoes drink (and almost all do), they die.

White-footed woods mosquito (Psorophora ferox) nectaring on goldenrod flowers.

You could then plant acres of the modified plant nearby towns to protect people from Zika (and anything else transmitted by mosquitoes). The beauty of this method is that you could reduce populations of mosquitoes from an area without spraying, and do so for generations if you modified nectar-producing perennials. I know it’s trendy to dislike GMOs (like vaccines), but I think many people would support them under these circumstances.

And yes, apparently Bti toxins can kill adult mosquitoes (including Aedes aegypti), not just larvae. Klowden and Bulla 1984 demonstrated it, for example. And yes, Aedes aegypti drinks nectar (and probably fruit juice).

Of course, even if somebody had the incentive to make such a plant, it could take a decade to wade through the red tape involved in getting non-regulated status from governments. So if you want to do something today, leave out containers of sugar water (10%) that is laced with Bti (e.g., Mosquito Dunks, which you can buy online or at hardware stores). Maybe add something floral to attract them, too. (A review of olfactory cues suggests that imitation cherry and apple can work. If you don’t have those sitting around, I’d wager a few drops of jasmine flavoring or rose water would work, and those are easily found at local stores.) Even if the Bti doesn’t immediately kill the adult, adults sucking up a big sugar meal can transfer the bacteria to water where they lay eggs, and thus eventually cause the death of any larvae that develop. Note that bees and ants might get interested in your sugar water, but the Bti is completely harmless to them.

And if you don’t want to use Bti, there are plenty of articles on using sugar baits laced with insecticides (e.g., Qualis et al. 2013, Junilla et al. 2015). They really can work: mosquitoes absolutely love sugar and will drink up poisons in the process. These are great if you don’t want to use crop dusters to destroy all insects in the area.

If you have kids and want to entertain them, add food dyes to the sugar bait and then challenge them to find mosquitoes with bellies full of sugar water. For older kids that might be amused by actual science, use two dyes to test attractiveness of two different volatiles (or different sugars). It’s probably rare to recapture one right after a nectar meal, but when distended they reveal gut contents nicely.

FYI, white-footed woods mosquito (Psorophora ferox) doesn’t transmit Zika, but illustrates to the unbelieving that mosquitoes do drink nectar.