Control

Ants (about 8,000 spp. within the Superfamily Formicoidea)

Grasshoppers (there are several families of grasshoppers, but the insects that usually constitute the most serious pests are species of Melanoplus, Family Acrididae) Gypsy moths (Porthetria dispar)

Japanese beetles (Popillia japonica)

Mealybugs (Pseudococcus spp.)

Mosquitoes (Culex spp., Anopheles spp., and others)

Red spider mites (Tetranychus telarius)

White flies

(Trialeurodes vaporariorum)

Ants that carry aphids into trees and consume ripening fruits can be prevented from getting farther than the trunk by applying a band of sticky material around the trunk. A commercial preparation sold under the trade name of Tanglefoot is particularly effective. A water suspension of ground hot peppers (Capsicum spp.) used as a spray can act as an ant deterrent. Caution: Many ants are beneficial to a balanced ecology; they should not be decimated indiscriminately.

In 1980, the Environmental Protection Agency permitted private companies to begin the mass culture of a protozoan, Nosema locustae, for use in controlling rangeland grasshoppers. Tests have shown that properly timed applications of spores mixed with wheat bran can reduce grasshopper populations by up to 50%.

Parasitic wasps (Apanteles flavicoxis, A. indiensis) imported from India lay their eggs in gypsy moth caterpillars and kill large numbers.

The pathogenic bacterium Bacillus popillae, which is sold commercially, is specific for Japanese beetle larvae. It causes what is known as "milky spore disease" in the grubs while they are still in the soil, and it is very destructive. It is available from St. Gabriel Laboratories, 14540 John Marshall Hwy., Gainesville, VA 20155 (1-800-801-0061 or http://www.milkyspore.com)

The small brown beetles called crypts (Cryptolaemus montrouzieri) effectively control mealybugs in greenhouses and also outdoors on apple, pear, peach, and citrus trees. Order from Rincon-Vitova Insectaries, Inc., P.O. Box 95, Oak View, CA 93022. The bacterium Bacillus thuringiensis var. israelensis has proved to be very effective in destroying mosquito larvae. A fungus (Lagenidium giganteum) has also proved highly effective against mosquito larvae if the temperature is above 20°C (68°F). The bacterium is available from several sources, including Abbott Laboratories, Dept. 95-M, 1400 Sheridan Rd., N. Chicago, IL 60064; Sandoz, Inc., 480 Camino del Rio S., San Diego, CA92108. Predatory mites (Phytolesius persimilis, which works best when weather is not hot, and Amblyseius californicus, which is more effective in hot weather) effectively control populations of red spider mites.

A minute wasp, Encarsia formosa, parasitizes white flies exclusively. The wasps have been known to be very effective in greenhouses. They are obtainable from White Fly Control Co., Box 986, Milpitas, CA 95035; Rincon-Vitova Insectaries, Inc., P.O. Box 95, Oak View, CA 93022. White flies are attracted to the color yellow. Large numbers of white flies are trapped when a yellow board is sprayed or painted with any sticky substance and placed in the vicinity of the pests.

they have observed. This does not mean that their observations are not useful or that they are invalid. In fact, such empirical observations have often been the inspiration for investigations and experiments by scientists. The scientific investigations have sometimes revealed that the empirical observations were biased or not carefully made or that erroneous conclusions had been drawn, but frequently, sound scientific bases for these observations have been uncovered.

Further insights into how plants inhibit or enhance the growth of others and into the nature of their resistance to disease or insect-repelling mechanisms continue to be discovered. Observations of such phenomena in the past have led organic gardeners and others to the practice of companion planting, which involves the interplanting of various crops and certain other plants in such a way that each species derives some benefit from the arrangement. The following companion planting list, based primarily on empirical information, appeared in the February 1977 issue of Organic Gardening and Farming magazine. It is included here with the permission of Rodale Press, Inc.

Table A2.3 is a list of combinations of vegetables, herbs, flowers, and weeds that are mutually beneficial, according to current reports of organic gardeners and to companion-planting traditions.

Biol, ogica.

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