Current Status of Pesticide Resistance in Insects and Mites Attacking Deciduous Orchard Crops

Abstract

Resistant strains of 18 insect and mite species are known to exist on deciduous orchard trees and vines. On apple the codling moth (<i>Carpocapsa pomonella</i> (L.)) is almost universally resistant in some degree to lead arsenate. More recently this insect has become resistant to DDT and certain DDT related materials in at least some plantings in most of the major apple-growing regions of the United States, Canada, South Africa and Australia. The red-banded leaf roller (<i>Argyrotaenia velutinana</i> (Wlk.)) has become resistant to TDE in many orchards in the eastern part of North America. On apple one species of leafhopper (<i>Erythroneura lawsoniana</i> Baker) in Kentucky was found to be resistant to DDT in 1953, and the white apple leafhopper (<i>Typhlocyha pomaria</i> McA.) in New York was discovered to be resistant to DDT and TDE in 1959. Most of the apple-infesting mites have developed resistance to parathion, TEPP, malathion, and other phosphate acaricides wherever these materials have been used regularly in the spray program. The European red mite (<i>Panonychus ulmi</i> (Koch)), Pacific mite (<i>Tetranychus pacificus</i> McG.), two-spotted spider mite (<i>T. telarius</i> (L.)), four-spotted spider mite (<i>T. canadensis</i> (McG.)), McDaniel mite (<i>T. medanich</i> McG.), and Schoene spider (<i>T. schoenei</i> McG.) mite have been reported resistant to at least one of these materials. <i>Tetranychus urlicae</i> Koch is resistant to parathion in Israel. The European red mite is also known to be resistant to ovex, chlorbenside, Fenson^® (<i>p</i>-chlorophenyl benzenesulfonate), Genite^® (2,4-dichlorophenyl benzenesulfonate), and Chlorobenzilate^® (ethyl 4,4′-dichloro-benzilate) in apple plantings. On pear the codling moth is generally resistant to lead arsenate and recently some resistance to DDT has been found in limited areas. The pear psylla (<i>Psylla pyricola</i> Foerst.) is resistant to malathion, parathion, toxaphene, dieldrin, and endrin in Washington and Oregon. The European red mite on pear in California is resistant generally to several of the phosphates and in a few plantings is resistant to at least one of the following: ovex, Genite, Chlorobenzilate, and Kelthane^® (1,1-bis{<i>p</i>-chlorophenyl) 2,2,2-trichloroethanol). On peach and plum the European red mite and the two-spotted spider mite are resistant to parathion and certain other phosphates. The green peach aphid (<i>Myzus persicae</i> (Sulz.)) has developed phosphate resistant strains in peach plantings in Washington and Oregon. The peach twig borer (<i>Anarsia lineatella</i> Zell.) is resistant to lead arsenate in California, and the oriental fruit moth (<i>Grapholitha molesla</i> (Busk)) may be partially resistant to DDT in Michigan and Virginia. On walnut the codling moth is becoming resistant to DDT. The walnut aphid (<i>Chromaphis juglandicola</i> (Kltb.)) and the European red mite are resistant to several phosphates. On grape the grape leafhopper (<i>Erythroneura variabilis</i> Beamer) has become quite resistant to DDT in California. Field entomologists have been successful in solving pest control problems created by the development of resistance primarily by employing chemically unrelated pesticides. In some orchards the practice of frequent changing from one pesticide to another as new and better materials became available has been observed to delay and perhaps prevent the development of resistance. Certain investigators are now suggesting planned rotation of orchard pesticides.