Effects on Nontarget Arthropods of Malathion Bait Sprays Used in California to Eradicate the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Dystera: Tephritidae)

Abstract

Evidence of bait attraction. direct kill. and populatiun reduction of nontarget arthropods was obtained by comparing gardens in two Malathion bait-sprayed sites with those in an untreated city and an unsprayed natural area. A variety of polyphagous and carnivorous arthropods were attracted by the baits, and in most cases fewer numbers were caught in treated than in cuntrol areas. Some phyto- phagous insects (Homoptera, Apidae. and Lepidoptera) apparently maintained or increased their pop- ulations during or after the spray period. Populations of calypterate muscoid !lies were probably unaffected by the sprays. Selective