Dipel Dust – A Biological Insecticide
Dipel Dust is a biological insecticide used against caterpillars, leaf eating worms, and other larvae, it is certified by OMRI (Organic Material Review Institute) for use in organic production. It is a microorganism Bacillus thuringiensis, Bt, subspecies kurstaki strain that is lethal to a variety of larvae after ingesting small amounts. It is safe for mammals, bees, birds, aquatic life, earthworms, pollinators, and many other beneficial insects. The only downside is that it will kill butterfly caterpillars, but as long as you use it sparingly and keep it off their favorite plants (rue or wormwood for example) you probably won’t notice any less butterfly activity. It is essential for organic brassica crops, because it kills loopers, cabbageworms, and more. If you have a tomato hornworm or fruitworm problem you can safely use it on your tomatoes. We prefer handpicking and interplanting with basil to deter them, we never seem to have much of a problem with hornworms. Mixing some in water and dipping seedlings in the mixture before you plant will take care of cutworms while your plants get established. Webworms, leafrollers, tent caterpillars and other tree and shrub pest can be taken care of with a generous dusting. Sod webworms bothering your lawn fall victim to Bt. This is only a small example of a large list of caterpillars and worms Dipel Dust is lethal to when ingested in small amounts.
Bt is usually used in a powder form, but can also be bought in a liquid form and sprayed on plants. Some people have had success injecting squash vines to stop the squash vine borers, timing is essential though, it must be done before too much damage has occurred.
I mix Dipel Dust in my potting soil for seedlings and houseplants, if I didn’t I would lose many plants to the larvae of the fungus gnats. They are a serious greenhouse and indoor plant pest. The adult flying gnat doesn’t bite or feed, but they are an indicator that you have a fungus gnat problem. The larvae cause damage by feeding on roots, plant exudates, algae, and fungus in the soil. They are a disease vector and slow down plant growth. They are the same gnats you may find in your fruit bowl. Bt sprinkled in all potting soil will prevent the problem from starting and clear up an infestation.
Mosquito Dunks are the israeli strain of Bacillus thuringiensis, it is a very effective, safe, and easy control of this summer pest.
Don’t be alarmed if you still see small amounts of the pest, as the adult that lays the eggs are not killed, and the worm/larvae must eat some of the plant material that has the Bt on it, then the worm will stop feeding and die shortly. Wasp and birds can still visit your garden for a snack if used sparingly, or if you get behind on dusting. I don’t mind sharing a little with the wildlife.
Regular use of Bt will greatly reduce crop damage done by fast eating caterpillars. Now you no longer have to eat lacy kale or cabbage, or spray large amounts of chemical pesticides on beloved trees under attack by worms.