Acoustical detection of oriental fruit fly (Diptera: Tephritidae) larvae in papaya

Ultrasensitive sound detection equipment was evaluated for identifying larvae of the oriental fruit fly, Dacus dorsalis Hendel (Diptera: Tephritidae), in papaya ( Carica papaya L.). In each of the eight laboratory tests, 25 fruit were artificially infested at a rate of 20 eggs per fruit; another 25 fruit were used as controls. After larval eclosion, each fruit was examined daily for 2 min using a computer program developed to recognize larval feeding. Accuracy in detecting infested fruit approached 100% 5 d after fruit infestation. The system correctly identified control fruit ca. 85% of the time until the sixth day, when tissue deterioration also produced signals. Factors causing false positives and problems with implementing the system in the laboratory are discussed.