DEVELOPMENT OF QUARANTINE ALTERNATIVES FOR SUBTROPICAL FRUIT AND VEGETABLE PESTS
Project Number: 6204-43000-015-00
Start Date: Nov 19, 2007
End Date: Jan 12, 2012
The long-term objective of this project is to develop methods to prevent introductions or establishment of pests into the United States through eradication, establishment of pest-free zones, and integration of pest management and post-harvest quarantine treatment systems to maintain or develop markets for fresh produce subject to quarantine barriers. Over the next 5 years we will focus on the these objectives: (1) Determine the population ecology, phenology, and reproductive behavior of tephritid pests of economic importance and other exotic pests that are pertinent to prevention of introduction and eradication of outbreaks in the United States; (2) Develop novel, chemically based tactics for detection and eradication or management of frugivorous fruit fly pests and other exotic pests of fruit production; (3) Develop post-harvest quarantine treatment systems for fresh fruit and vegetables that meet international requirements for security and safety; and (4) Integrate quarantine treatments, pest eradication, or pest management strategies into systems approaches for quarantine security implementation and trade enhancement.
USDA-APHIS will be releasing marked sterile Mexican fruit flies in Rio Bravo and Reynosa, Mexico. By running lines of traps at set distances on the Texas side, we can obtain a measure of the dispersal capacity of these flies and a measure of the theory that wild fertile flies enter the USA from Mexico. Anastrepha species will be collected and preserved in numerous locations in Mexico and Central America. Molecular techniques will be used to analyze DNA to detect genetic differences in populations. Various sources of potential behavior-modifying chemicals will be investigated. Chemicals will be identified, assayed for behavior-modifying effects, and combined with other chemicals into highly attractive combinations. Formulations of the effective blends will be developed into lures and their efficacies evaluated in field tests. Chemicals that repel flies in initial tests will be assessed for potential as oviposition deterrents. Novel blends of semiochemicals will be tested as bait attractants. Feeding studies with new mixtures of phagostimulants to improve toxic baits for several species of flies will be conducted. Tolerance of guavas and avocadoos to irradiation, methyl bromide fumigation, cold storage, heated air, and hot water immersion treatments will be determined experimentally by treating commercially-obtained fruit near dose ranges known or suspected to control Mexican fruit fly. The most radiotolerant stage of the European corn borer will be irradiated with increasing doses until those necessary to prevent development and/or reproduction to a high level of security are achieved. Grapefruits will be infested by placing in cages with Mexican fruit fly adults, fumigated with the approved schedule, and evaluated for mortality to larvae within by opening the fruit at periodic time periods after fumigation. Soil treatment controlling the prepupal and pupal stages of fruit flies can be developed that are compatible with SIT as alternatives to Diazinon or organophosphate pesticides. Initial phase of testing is conduced in the greenhouse using tubs containing 0.3 cubic meter or orchard soil. Full grown larvae are introduced into the soil and allowed to seek natural pupation depth, which we find to be typically 2-5 cm. Host status for a fruit fly species is determined by a number of steps. First is a complete review of biological literature considering taxonomy of the species, known hosts, and analysis of host testing performed on the species. If reliable reports do not exist, lab colonies will be established for testing the acceptability of the fruit to the species under forced lab conditions. Effective implementation of a system approach strategy to meet quarantine requirements will be evaluated on a monthly basis with program operators. Decisions concerning how available resources are applied to the tactics will be determined by analysis of experimental data.