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14. Consider Using Biological Insecticides

stages of insect development

Biological insecticides are actual living organisms or the toxins produced by them. Examples include viruses, bacteria, fungi, and nematodes.

The chief benefit of using biological, or microbial, insecticides is their low toxicity to humans and nontarget insects. Some of these insecticides are so selective that they affect only one part of the life cycle of the insect, such as the caterpillar (larva) stage of moths and butterflies. The low toxicity also means less risk to groundwater and surface water.

insecticide label But there are drawbacks. Biological insecticides do not have as long of a shelf life as conventional pesticides, so proper storage is critical. In addition, certain microbial pesticides can lose their effectiveness rapidly if exposed to heat and ultraviolet radiation, or when they dry out. For this reason, proper timing and application procedures are extremely important.
newly hatched worms When looking for biological insecticides, keep a few points in mind. Biological insecticides probably will not control heavy pest populations, but they can control moderate populations of newly hatched worms. Biological insecticides must be ingested by the larvae, which will stop feeding within a few hours and die within two to five days. Also, most currently available biological insecticides are highly selective for the control of certain caterpillars.
Bacillus thuringiensis In many states, some of the biological insecticides available for use in field crops include Biobit, Dipel, Full-Bac, and Javelin. The common denominator among all of these products is that they contain the active ingredient Bacillus thuringiensis, or Bt, a bacterium.
biological insecticides The different biological insecticides may be formulated as dry or wettable granules, emulsifiable suspensions, or flowable concentrates. Crops for which some or all of these insecticides are registered include alfalfa, corn, small grains, sorghum, and soybeans.
biological insecticides - target insects The insects listed on some or all of the labels are alfalfa caterpillars, armyworms, corn earworms, cutworms, European corn borers, fall armyworms, green cloverworms, and webworms. As with synthetic chemical insecticides, it is extremely important to read the label of biological insecticides. The different products vary in terms of application rates, methods, timing, and placement.
Bt corn Another avenue for using biological insecticide is Bt corn. Advances in genetic engineering now allow the transfer of genes from one species to another. By implanting the bacterium, which is not toxic to people or animals, directly into the genetic make up of the corn, the crop is resistant to first-generation corn borers.

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