Mosquitoes and Caterpillars Beware!
By: Arbico Organics Staff
One of the most successful biocontrol agents on the planet is Bacillus thuringiensis (varieties Bti, Btk and Btt). It is particularly popular this time of year with mosquitoes on the loose, caterpillars munching away and Colorado Potato Beetles that missed the squish patrol. Different strains of these bacteria have different activities against different insects. Each strain is entirely specific to the narrow range of insects for which it is labeled, with Btk being the most general. These bacteria are incredibly effective and safe for all creatures except the ones you're targeting.
Bti, found in mosquito dunks and "Quick Kill Bits" is effective against mosquitoes and a couple other water breeding close relatives but does not harm dragonfly larvae. Contrary to popular belief, mosquitoes can even breed in consistently damp areas so be sure to treat even those moist areas under shrubs, compost piles, etc.
Btk, found in the products Dipel and Thuricide is perfect for the veggie garden. It is effective against all those plant-eating members of the Lepidoptera (moths and butterflies) and is safe for other insects. Do not use these products in your butterfly garden! Luckily, Btk stays where you put it so you can spray your corn but not the specialty larval food plants you cultivate for your favorite butterflies.
Btt is mostly available not as the whole bacteria but rather just the toxins produced by these bacteria. Products containing this toxin are usually just called "Potato Beetle Killer" and are effective exclusively against potato beetles.