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Cygon for Fruit Trees

over-laden fruit tree image by Alfonso d'Agostino from

Almost all fruit trees are plagued by insects. Usually it is quite a few species, but the most common ones are aphids, scale, mites and leafminers. Cygon is the manufacture name for products like Bonide and Hi-Yield. They are designed for insect control on flowering trees and shrubs. There is an industrial formula, 4-E, that is for use in crop sprayers. The 2-E formula is designed for home gardeners.


All Cygon products contain dimethoate, the active ingredient. Industry products are made for use in backpack sprayers or even crop dusters, so application is a dilution of the poison. The targeted home products are either spray concentrations or granulated for systemic introduction. They can be diluted and applied using a garden hose sprayer or worked into the soil. Spray application must be done onto dry foliage and several hours before rain.


Dimethoate is in a class of insecticides called organophosphates. They interrupt the activities of cholinesterase, which is the enzyme that helps control the nervous system in both insects and humans. Dimethoate is biodegradable. It breaks down in soil and is not absorbed. It does not accumulate in the sediment in water bodies and it degrades in sewer treatment facilities. Temperatures above 80 degrees Fahrenheit cause it to decompose rapidly.


A large number of insects are the targets of Cygon. The cherry fruit fly has been controlled successfully by Cygon administration. A pre-harvest and post-harvest spray are necessary to get the most control. Affected insects are thrips, aphids, leaf miners and leaf hoppers and whiteflies. It has also been used as a housefly pesticide and been administered to livestock to kill botflies. Both dusting and spraying methods are appropriate for insect control.

Toxicity and Warnings

The active ingredient in Cygon, dimethoate is very toxic. It has been shown to cause mutations, birth defects and cancer in laboratory animals. It is rapidly metabolized in animals and humans and can be virtually undetectable in the body within 24 hours of ingestion. Cygon can be absorbed through the skin and lungs. The species most affected are fish and birds. Birds are especially susceptible to toxic affects and will die if exposed. Honey bee populations can be decimated by single organism contact as the chemical is brought back to the hive and affects the whole population.


Cygon is a systemic insecticide. It works by moving into the plants vascular system and invading all the plant cells. Insects that feed off the plant ingest the chemical through plant saps and die. Cygon can even be painted onto the bark of a tree and it will be absorbed through the cambium and into core tissue. This is useful when dealing with insects that live in the tree. Cygon works particularly well on leaf miners who live inside the leaf. Foliar application will result in the leaf absorbing the chemical and transferring it to the insects.

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