Deterrent Effect of Neem Seed Kernel Extract on Oviposition of the Oriental Fruit Fly (Diptera: Tephritidae) in Guava

In laboratory choice and no-choice tests, guava, Psidium guajava L., fruits treated with neem seed kernel extracts resulted in reduction in ovipositional preference of the oriental fruit fly, Bactrocera dorsalis (Hendel). In the choice test, the number of eggs laid in treated guava fruits at concentrations ranging from 0.2 to 4.0% was reduced from 87.5 to 99.2% compared with eggs in untreated fruit. Flies were not habituated to neem-treated fruits at concentrations of 0.2% or higher in 7 d. When a yellow plastic oviposition container filled with guava juice was placed together with a fruit treated with 4.0 or 20.0% extracts in a cage, all eggs were laid in the former, and none in the latter. These results indicate that neem seed kernel extract is an ovipositional deterrent for the oriental fruit fly.