Tuesday, March 20, 2012

Organic Insecticides

                                                                                                                                  Here is a list of materials most commonly used and often accepted as organic insecticides:  

·        Bacillus thuringiensis (Bt) -  for the control of many lepidopteran larvae (butterfly/moth), mosquito and beetle larvae. Some trade names include, dipel, gnatrol, biobit and javelin.
·        Diatomaceous earth –An abrasive and absorptive powder made from the shells of diatoms - fossilized remains of microscopic, marine organisms.  This white powder causes dehydration in pests such as ants, cockroaches, snails and slugs.
·        Insecticidal oils – controls aphids, scale insects, mites, as well as aphid and mite eggs.
·        Neem – a plant derivative; controls a broad range of insects.  Low human toxicity.
·        Pheromones – these are chemical attractants used mainly for monitoring insect populations.  They can also be used to confuse insects in order to disrupt mating. Occasionally they are used to catch large numbers of specific insects like fruit flies to reduce future generations.
·        Pyrethrum –  a natural insecticide made from the dried flowers of certain species of chrysanthemum. During the Napoleonic Wars (1804-1815) this “insect powder” was used to control flea and body lice infestations by French soldiers. A disadvantage to this natural insecticide is its sensitivity to sunlight.  It can break down in as little as 12 hours.

A group of synthetically produced, similar compounds called pyrethroids are more stable in sunlight, therefore more environmentally persistent and, in general, are more toxic. Examples of synthetic pyrethroids are, allethrin, bifenthrin, cyfluthrin, permethrin and resmethrin.  These names will be  listed under active ingredient.
·        Soaps – controls mites, aphids and other plant-sucking arthropods.  May cause some plant burn under certain conditions. 
·        Vegetable oils – used as a contact spray to control scale insects, aphids and mites.