Targeted Trapping, Bait-Spray, Sanitation, Sterile-Male, and Parasitoid Releases in an Areawide Integrated Melon Fly (Diptera: Tephritidae) Control Program in Hawaii

Abstract

An areawide integrated pest management approach to melon fly Bactrocera cucurbitae (Diptera: Tephritidae) suppression in Kamuela, Hawaii, was undertaken as part of a larger statewide program by the U.S. Department of Agriculture–Agricultural Research Service (USDA–ARS), Areawide Initiative. After a survey on five islands, a grid of 1 trap/km 2 over 40 km 2 was established in Kamuela to locate areas of infestation. Then a targeted male trapping array was applied based on the distribution of host plants, and these were mapped using geographic information systems. Trap density was determined by monitoring existing traps and by increasing density where catch was high. Sanitation of crops, application of GF120 Naturalyte NF bait spray, Sterile Insect Technique (SIT), and augmentation of Psyttalia fletcheri parasitoids were also used. Pretreatment trapping in the farming area indicated a melon fly population peak of 11.94 ± 9.90 flies/trap/day (f/t/d) on 30 Oct. 2000. By 2003, the average catch of the grid traps over 16 wk was 0.016 ± 0.005 f/t/d per km 2 , a 99.87% reduction. Some resurgence of melon fly population to a 12-wk average of 0.191 ± 0.79 f/t/d per km 2 occurred when USDA discontinued SIT and parasitoid release and bait spray applications. Resurgence occurred primarily in the off-farm areas where growers had not adopted the three suppression techniques (sanitation, bait spraying, and male annihilation). Restoring USDA bait sprays application and briefly reapplying SIT returned the population to a mean of 0.033 ± 0.004 f/t/d per km 2 between 20 Jan. and 5 April 2004. Between August 2002 and August 2003, infestation in all fruits observed over 40 km 2 averaged 14.3 ± 2.9%. In 2002, with all suppression activities implemented, the infestation rate averaged 8.5 ± 4.8% in sampled fruit. That is an 83.2% reduction compared with the 2000–2001 mean infestation of 50.6 ± 4.9%.