1a. Objectives (from AD-416)
The objectives of this cooperative agreement are three-fold: 1) to develop, evaluate and transfer non-toxic, environmentally suitable and publicly acceptable technologies and processes for fruit fly pest management in order to enhance the production and interstate and international movement of Hawaiian agricultural commodities; 2) to identify and characterize effective environmental and economic impacts of technologies and processes for fruit fly control; and 3) to investigate the establishment of fruit fly low-prevalence zones to facilitate interstate and international movement of Hawaii agricultural products.
1b. Approach (from AD-416)
The approach to this project is to address the development and evaluation of currently acceptable or novel non-toxic fruit-fly control strategies such as classical biological controls; post-harvest treatments, microbial control agents; behavioral genetic and ecological controls and others, while identifying potential environmental problems and developing solutions associated with currently acceptable or novel fruit fly control strategies in a variety of Hawaii agricultural systems (such as coffee, papaya, guava, citrus, lychee, mango and other fruit and vegetables). Documents SCA with University of Hawaii; formerly 5320-22430-021-22S (8/09). Formerly 5320-22430-021-26S (11/10).
3. Progress Report
This project has supported 5 subprojects, which are covered under this report. Significant finding has been made in determining the distribution and relative abundance of all native tephritid species on the major islands of Hawaii. Using Geographic Information System (GIS) technology, detailed biogeographic models have been developed to predict the distribution of the most abundant species in the genus Trupanea and to delineating the zones in which pest tephritids (Ceratitis and Bactrocera species) overlap with native teprhitids (primarily Trupanea species). Thus, the models will help mitigate impacts on non-target species in a planned eradication or area-wide suppression program against these agricultural pests. Determination of the phylogenetic relationship among the Bactrocera dorsalis complex species is critical to the management of the economically important fruit flies in the world. Using Methyl eugenol, Cuelure and Torula yeast, a total of 4,500 specimens of fruit flies were collected from 140 sites in Thailand, Cambodia, Laos, and Malaysia. Of these specimens, 50 species were morphologically identified under two genera (Bactrocera and Dacus), and six subgenera (Bactrocera, Caculus, Zeugodacus, Sinodacus, Notodacus, and Calantra). Majority (74%) of the flies collected belonged to B. dorsalis complex. Additionally, 17 were categorized as undescribed new species as they were distinctively dissimilar to the described species. To determine the phylogenetic relationship among the species, DNA was extracted and sequenced 790 base pairs of the mitochondrial gene COI. Of these, 175 were selected for an in depth study. The results showed that the B. dorsalis complex is paraphyletic and analysis of the mitochondrial sequence data revealed that B. dorsalis, B. papayae, B. philippinensis, B. carambolae and B. invadens are genetically similar with less 1.5% genetic differences. This project also demonstrated that inbreeding depression could arise in biological control agents, and that the fitness of the agents can be reduced when a laboratory strain of an insect species was crossed with a wild strain of the same species, which often occurred in augmentative releases of biological control agents. This finding warns against flooding of wild fruit fly populations with biocontrol agents bred in captivity. This project also made a significant finding in that lufennuron, a chemosterilant mixed in a fruit fly bait, effectively reduced pupal recovery, pupal weight, adult emergence, adult mating, egg hatch, and egg production in the Medfly and the oriental fruit fly. This finding will enhance the effectiveness of the control of tephritid fruit flies with chemicals that are effective, new, natural, and environmentally safe. Ultimately, it will enhance attaining the goals of improvement of the quality and competitiveness of US agricultural products in the world market. Project was monitored through meetings, site visits, and telephone and email communications.