Just what are biological insect controls, anyway?

There are a number of products on the market that advertise they are biological insect controllers, and it is important to understand how some of these products work. Just because a product is made from natural ingredients does not mean it is necessarily non-toxic or safe for the environment. 

For an organic garden, you need to keep in mind what your priorities are. If you do not want to use any pesticides what-so-ever, then handpicking bugs and barriers (such as floating row covers) may be your main options. There may come a point when you need some help, and there are products out there that can do that for you.

BACILLUS THURINGIENSIS

I am a big proponent of Bt (Bacillus thuringiensis and it’s counterparts) as it is totally biodegradable, non-toxic to humans, pets, fish, birds. It affects the digestive system of caterpillars when they eat the treated plant. Although it will also kill caterpillars of butterflies, they rarely eat the type of vegetable plant of concern. To be safe, don’t spray ornamental flowers that normally attract butterflies. Another reason I consider Bt a really good product is that you spray the plant that is being attacked, not by contact on each individual insect.

ROTENONE

Although this insecticide is made from natural ingredients and is biodegradable, it is not non-toxic. It is a contact insecticide (you have to actually spray the insect itself to work) and is not allowed to be used on produce to be sold as organic.

PYRETHRUM

This too is a synthetic insecticide made from Chrysanthemums. It is highly toxic to fish and honey bees. It is a contact insecticide, and considered to have a low toxicity to humans. 

SAFER INSECTICIDAL SOAP

This product is made from natural oils and animal fats and is effective against aphids, scale and other soft bodied insects. It is considered non-toxic to humans and approved for use on organic produce. The downside is if you apply it in really hot weather in a sunny location you could damage your plants.