2009 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, vitiamin 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).
Fruit fly liquid larval diet technology was successfully transferred to 3 major medfly mass rearing facilities and 2 Bactrocera facilities. All of these facilities have the common problem of spent diet management, including the quality, cost, handling, and space occupied by the currently used bulking agent. Liquid diet technology can help solve this problem. The Stellenbosch, S. Africa, medfly rearing facility has been struggling with inconsistent quality of both the bulking agent (bran) and spent diet management including labor, space, and biosecurity. SIT Africa has agreed to adopt liquid diet technology into their rearing program as soon as the new rearing building is completed. The El Pino, Guatemala facility has a high cost of their bulking agents (corn cob and sugarcane bagasse) and the need to dispose of 35 tons of spent diet each day. Liquid diet technology would release them from purchasing pricey bulking agents and avoiding the need for spent diet management. They are planning to modify the current sponge cloth design and diet formulation to fit their needs and possibly use a starter diet as the first step of adopting liquid diet technology. The Valencia, Spain facility has been trying to substitute their current bulking agent (sugar beet pellet) to simplify their rearing procedure. The sponge cloth we use in liquid diet technology has led them in a new direction. Liquid diet technology is workable for them if they can designate a clean, humidity controlled room specific for liquid diet rearing. They are currently working to increase production and avoid the contamination due to high humidity in the rearing facility.
Considerable progress was made on developing new strains and irradiation dose levels needed for SIT technology against the invasive tortricid moth species, the light brown apple moth (LBAM). The species likely invaded California from Australia or New Zealand, the former being its native home. In collaboration with colleagues from Australia and N. Zealand, we collected new colony material from a resident population in Volcano, Hawaii in 2007, and have developed a suitable larval diet based on pre-existing LBAM diets. In addition, we worked on identifying suitable irradiation doses to sterilize young adults of the species, and have succeeded in specifying a dose range, 250-300 Gy. During the summer of 2009, there will be pilot sterile moth release tests performed in infested areas of California as the first step towards achieving an operational SIT program against this species in the US.
Research on fruit fly quality control continued in field cage studies of the cost benefits of holding sterile flies longer prior to release into the field. We conducted tests comparing the standard release of ca. 2 day old flies vs. release of 5 day old flies. We measured the pre-release mortalities of 2 vs. 5 da old flies and compared that to assessments of field survival as measured by traps. We found that releasing flies at the older age results in several times more flies surviving to the critical mating age of ca. 5 da. Thus, an SIT program would likely benefit significantly from holding flies longer before releasing them.
Development of sterile insect technology to control the light brown apple moth (LBAM). The LBAM is a serious pest that attacks plants of many kinds and poses a threat to both agricultural and non-agricultural areas of California, as well as to the rest of the United States. ARS scientists at Hilo, HI have continued studies to develop a good larval diet for this species based on previous diets, and also to provide a suitable irradiation dose range for LBAM adults that could be used in a Sterile Insect Technology (SIT) program. The potential impact of this accomplishment will be the development and implementation of environmentally safe and sound SIT technology to better protect the multi-billion dollar agricultural industry in California and elsewhere across the United States.
Fruit fly liquid larval diet technology successfully transferred to rearing facilities worldwide. All fruit fly mass rearing facilities have a common problem in managing spent diet management including quality, cost, handling, and space occupied by the various bulking agents currently used. ARS scientists in Hilo, HI have successfully transferred fruit fly liquid larval diet technology to three major medfly mass rearing facilities in South Africa, Guatemala, Spain. The diet is also being used in rearing facilities for two Bactrocera species at the Nuclear Research Institute in Manila, Philippines and the Insect Biotechnology Division, Institute of Food and Radiation Biology, Atomic Energy Research Establishment in Bangladesh. With this technology, the spent diet management problem can be solved, permitting managers to achieve cost effective rearing in order to provide good quality fruit flies for SIT programs.
|Number of the New/Active MTAs (providing only)||3|
|Number of Other Technology Transfer||4|
Chang, C.L., Mcinnis, D.O. 2008. Evaluation of the Mating Competitiveness of the Adult Oriental Fruit Fly Reared as Larvae in Liquid vs. Those Raised on Standard Wheat-based Diets. Journal of Applied Entomology. 132: 806-811
Chang C. 2009. Evaluation of yeasts and yeast products in larval and adult diets for the oriental fruit fly, Bactrocera dorsalis, and adult diets for the medfly, Ceratitis capitata, and the melon fly, Bactrocera curcurbitae. 9pp. Journal of Insect Science 9:23, available online: insectscience.org/9.23
Chang, C.L., Ilkyu, C., Qing, X. 2009. Insecticidal Activity of Basil Oil, trans-Anethole, Estragole, and Linalool to Adults of Ceratitis capitata, Bactrocera dorsalis, and B. cucurbitae. Journal of Economic Entomology. 102: 203-209.
Chang, C.L. 2009. Fruit Fly Liquid Larval Diet Technology Transfer and Update. Journal of Applied Entomology. 133: 164-173