2008 Annual Report
1a.Objectives (from AD-416)
The primary goal of the project is to develop efficient means to rear and evaluate insects used in autocidal or biological control methodologies. Our project has 3 objectives that interact in a dynamic manner. These objectives include the.
2)quality control testing, and.
3)strain development of tephritid fruit fly pests and their beneficial parasitoids. Existing diets for fruit flies continually need to be improved in order to reduce costs and maintain or increase fly quality. New or existing strains must be regularly monitored for quality to know when they should be replaced or improved; therefore, having a battery of quality control tests or procedures is imperative. Such quality tests need to be cost efficient in discriminating among candidate strains, and whenever possible, measured against wild strains as standards for comparison.
1b.Approach (from AD-416)
For the first objective on rearing technology, we propose to examine various methods including: refinement of the existing defined larval and adult diets, new diet bulking agents, and sugar substitutes. The approach will be to compare new diets formulated based on new knowledge of nutrition, vitamin requirements and bulking agents with the existing diets used for mass-rearing of flies. Data to be collected will include developmental time, days from egg to pupation, overall yield and size of larvae and pupae at different developmental stages. This work will focus on the Mediterranean fruit fly initially, then later on other fruit fly (esp. Bactrocera) or parasitoid species. For the second objective on quality control, we propose to emphasize evaluations of flies for field cage mating competitiveness and survival ability, and of parasitoids for field cage parasitism rates and survival ability. This will be accomplished by visaul observation of fly competitiveness and behavioral characteristics (including mating) in standard field cages. Data from different strains will be compared with currently mass-reared laboratory strains and wild field strains.For the third objective, standard genetic tools will be used for developing new genetic sexing strains in the Bactrocera, especially for B. latifrons. Standard gentetic tools will include pairing of wild and lab strains, and low dose irradiation for translocation lines that might reveal superior traits to the existing strains. The existing melon fly and oriental fruit fly genetic sexing strains will continue to be field evaluated in current or new sterile insect release programs in Hawaii or elsewhere in the Pacific or Asia. Formerly 5320-22430-019-00D (4/05).
A significant advance in rearing technology was made with the development of a liquid larval diet for the Mediterranean fruit fly, Ceratitis capitata, along with a refinement of the existing liquid larval diet for the oriental fruit fly, Bactrocera dorsalis and the melon fly, B. cucurbitae. Mating competitive tests both in field and lab cages were conducted. The results showed that both standard strain and genetic sexing strains were equally competitive. It means the liquid diet reared flies are as competitive in mating as those reared in traditional larval diets. The technology of these new liquid diets can potentially significantly reduce the high cost of larval diets for several species of fruit flies. This technology has been successfully demonstrated and transferred to the Stellenbosch, South Africa medfly rearing facility (January, 2008). Currently, it is under on site mass rearing evaluation and should result in significant savings in rearing costs of materials, labor, and space without compromising fly quality. Liquid larval diet starter kits have been sent to 36 countries for 25 different fruit fly species to evaluate the possibility of rearing these species on liquid diets using their own local materials.
A large-scale field evaluation of the existing pupal color sexing strain of the oriental fruit fly was conducted, including the successful development and comparison of a new sperm identification method for this species in order to monitor the field performance of sterile males. The successful development and field evaluation of a genetic sexing for the oriental fruit fly now means that the release of all male sterile flies can result in significant improvements in the quality of released flies with a consequent improvement in the efficiency of the SIT. Further, the impact of these accomplishments is better protection for the multi-billion dollar agricultural industry in California, Florida and Texas.
NP304, Component 4
Development of sterile insect technology to control the light brown apple moth (LBAM)
This serious pest which attacks plants of many kinds, poses a threat to both agriculture and non-agricultural areas of California, as well as to the rest of the United States. The ARS Tropical Plant Pests Research laboratory in Hilo, HI has begun to study this moth in order to develop new approaches to control the pest without using insecticides- namely with the sterile insect technique (SIT). We started a colony of LBAM from wild populations in Hawaii and have begun irradiation and mating studies to develop the baseline SIT information, in collaboration with Australian and New Zealand colleagues. The impact of these accomplishments will be better protection for the multi-billion dollar agricultural industry in California and elsewhere across the United States. This research was conducted under NP-304, Component VI, Postharvest, Pest Exclusion, and Quarantine Treatment. Problem being addressed: d)Fundamental Biology and Ecology of Exotic Insect Pests.
Large-scale implementation of tephritid fruit fly liquid diet technology
The cost of mass-rearing insects for sterile insect release programs is very high, especially for the bulking agents involved and for labor. Liquid diet technology can potentially reduce $75,000 from the cost of the diet bulking agent per year, and 30 hours per week of labor in scrubbing the spent diet from diet trays before washing. It also will reduce the space required for insect incubation because this technology can rear all three larval instars in one single temperature room without moving to different rooms with different temperature regimes. Thus, new liquid diets can potentially significantly reduce the high cost of larval diets for sterile insect programs against several species of fruit flies. ARS scientists at the Tropical Plant Pests Research Laboratory in Hilo, HI, gained recognition from their small scale rearing success which led to current large-scale evaluations at several medfly mass-rearing facilities around the world. This research was conducted under NP-304, Component VI, Postharvest, Pest Exclusion, and Quarantine Treatment. Problem being addressed: d)Fundamental Biology and Ecology of Exotic Insect Pests.
5.Significant Activities that Support Special Target Populations
|Number of the New MTAs (providing only)||6|
|Number of Invention Disclosures Submitted||1|
|Number of Non-Peer Reviewed Presentations and Proceedings||13|
Chang, C.L., Caceres, C., Ekesi, S. 2008. Life History Parameters of Ceratitis capitata (Diptera: Tephritidae) Reared on Liquid Diets. Annuals of the Entomological Society of America. 100(6):900-906.