1. CRP Title "Development of Female Medfly Attractant Systems for Trapping and Sterility Assessment" 2. Section/Division: Insect Pest Control / Joint FAO/IAEA Division (NAFA) 3. Project Officer: Jorge Hendrichs 4. Period Covered: 1994-1998 5. List of Participants Name Vattuone, Enrique Camacho, Hernan Katsoyannos, Byron Jeronimo, Felipe Vasquez, Luis Seewooruthun, Indira Montoya, Pablo Bakri, Abdeljelil Pereira, Rui Barnes, Brian Ros Amador, Pedro Zumreoglu, Aydin Howse, Phillip Heath, Robert Institute/Country Universidad de Catamarca, ARGENTINA Universidad de Costa Rica, COSTA RICA University of Thessaloniki, GREECE Programa Moscamed, GUATEMALA FHIA, HONDURAS Ministry of Agriculture and Natural Resources, MAURITIUS Programa Moscamed, MEXICO University Cadi Ayad, MOROCCO Plant Protection Directorate, Madeira, PORTUGAL INFRUITEC, South Africa Inst. Nacional Invest. Agarias, SPAIN Plant Protect. Research Institute, TURKEY University of Southampton UNITED KINGDOM USDA/ARS Research Co-ordination Meetings: Date May 22-26, 1995 January 20-24, 1997 May/June 28-1,1998 Location Antigua, Guatemala Funchal, Madeira Penang, Malaysia
Page 2 6. Objectives of CRP Overall The overall objective of project D.4.03: Development of environment-friendly supportive technology that increases the effectiveness of SIT based insect pest control programmes is to develop and transfer technologies that integrate with, and increase the effectiveness of, nuclear techniques for the environment-friendly control of agricultural pests. (b) Specific The main objective of the project was to develop a trapping system for female medflies which can be deployed as a detection and monitoring tool in SIT programmes using a genetic sexing strain. A secondary objective was to develop a female specific trap from which eggs of wild females can be obtained to estimate sterility which has been induced as a result of sterile male releases in the wild population. 7. Outputs: Research An effective method for population estimation, which accurately reflects changes due to movement, mortality or reproduction, is a prerequisite for the success of any insect pest control operation. For SIT in particular, efficient and precise methods are needed to monitor the feral pest population before sterile insect releases begin, to monitor the decrease of the pest population during the release campaign, and to survey the area following eradication for possible re-introduction. A previous CRP on "Standardization of Medfly Trapping for Use in Sterile Insect Technique Programmes" (IAEA TECDOC 883) concluded that even though different trapping systems are available to monitor male medflies under different conditions in tropical and subtropical climates, there is a distinctive lack of an effective and practical trapping system for female medflies, the sex responsible for the damage caused by medflies. The application of SIT against medfly would be greatly facilitated by such a female trapping system. With the development and use of genetic sexing or male-only strains in SIT campaigns, such a female specific trapping system becomes indispensable. Capture of released sterile males would be greatly reduced and captured female flies would be mostly from the wild population. This would considerably reduce present costs required to discriminate between marked sterile males and unmarked wild males and reduce the uncertainty due to misidentifications and contamination of the wild flies with dye. In addition, a female trapping system would allow measuring SIT campaign progress through the egg sterility induced in the wild population as a result of the release of sterile males. After the conclusion of the CRP one can conclude that outputs achieved have considerably surpassed the expectations of all participating scientists. First, a two component food bait (ammonium acetate and putrescine), formulated into a slow release membrane that is effective for at least 4-8 weeks depending on the prevailing temperatures and winds, proved to be a significantly better and practical medfly female attractant than any of the products previously available on the market. During the second phase of the CRP, a third component (trimethylamine), also the result of the technical contract given to the chemist R. Heath of the
Page 3 US Dept. of Agriculture, has shown to be synergistic to the 2-component lure, increasing several fold the capture of females, and often even surpassing the capture of males in the best male attracting systems. As a result, a number of scientists asked for permission to participate as observers in the following RCMs and to carry out the same protocols in their countries at their own cost. The last part of the CRP was dedicated to validating these findings in all participating countries in order to optimize the attractant and trap combinations for each climate and situation, so that specific operational recommendations would be available at the end of the CRP for operational SIT programmes. (b) Others Other outputs involve transfer of the research results to SIT projects, scientists and technicians trained in carrying out the protocols and the collection and analysis of data, as well as the establishment of a network of scientists collaborating in this field in over fifteen countries. Various companies competed to market the resulting three-component lure to capture female medflies, which is now available commercially and already being bought by a number of operational medfly SIT projects. 8. Effectiveness of CRP In reaching Specific Objective The specific objective of developing a trapping system for female medflies which can be deployed as a detection and monitoring tool in SIT programmes using a genetic sexing strain was not only fully achieved, but it was also validated and transferred to medfly SIT projects. Considerable progress was also made in relation to the secondary objective of developing a female specific trap from which eggs of wild females can be obtained to estimate sterility which has been induced as a result of sterile male releases in the wild population, although some more research is required to develop a more practical method to assess the induced sterility in females of wild populations. (b) In contributing towards Overall (i.e. Agency project) Objective The development, validation and transfer of a medfly female attractant represents a major contribution towards the overall project objective of developing environment-friendly supportive technologies that increase the effectiveness of SIT based control programmes against major insect pests, in this case medfly. This technology complements perfectly the use in SIT projects of medfly genetic sexing strains, another technology developed by the Agency. (c) Factors, if any, which adversely affected the effectiveness of the CRP It was very appropriate for the Agency to have undertaken the CRP because it addressed a clear case of unsatisfied demand and an opportunity to add value to a nuclear technology. The medfly female trapping system would not be currently available, had the agency not been a major catalyst in its development, standardization and validation, as well as its active transfer to operational medfly SIT projects. The CRP was appropriately formulated, and most participating institutions provided the expected inputs.
Page 4 9. Impact of the CRP Methods for population estimation, which accurately reflect changes due to movement, mortality or reproduction, are a prerequisite for effective pest management and in particular for application of SIT. Even though different trapping systems are available to monitor male medflies, there was a distinctive lack of an effective and practical trapping system for female flies, the sex responsible for the damage caused by medflies. The application of SIT against medfly would be greatly facilitated by such a female trapping system. Following the development of male only genetic sexing strains by the Agency, it was recognized that the development of female medfly targeted trapping system, in conjunction with only male sterile releases, would improve the efficacy of the SIT, reduce costs, and more effectively utilize sterile males. Capture of released sterile males would be greatly reduced and captured female flies would be from the wild population. This would considerably reduce present costs required to discriminate between marked sterile males and unmarked wild males and reduce the uncertainty due to misidentifications. The objective of this CRP, to develop a female medfly trapping system and to determine its efficacy under different climatic and population density conditions, was fully achieved. The resulting three component food bait (ammonium acetate, putrescine and trimethylamine), proved to be a significantly better and practical medfly female attractant than any of the products previously available on the market, increasing several fold the capture of females. The lure was evaluated and validated in different trap types in fourteen different countries and climates in northern and southern Africa, southern Europe, Central and South America and the Indian Ocean, where the production of fruits preferred by the medfly is important. Used in conjunction with only sterile male releases, this female trapping system, opens the possibility of simpler and more accurate appraisal of the progress of the SIT programmes, and has resulted in a commercial lure already in use not only in operational SIT control and eradication programmes, but also in conventional monitoring, where the medfly is a major pest or has the potential to become established. 10. Relevance of the CRP Based on requests by Member States to develop similarly effective female trapping systems for other fruit flies of economic importance, a new CRP will be initiated directed at various fruit flies of the Genera Anastrepha, Bactrocera and Ceratitis, as well as to initiate the development of mass trapping techniques using bait stations for medfly. 11. Recommended future action by Agency Future coordinated research in this supportive field to increase the effectiveness of SIT should focus on developing female attractant systems for other economically import fruit fly species, and on maximizing the usefulness of these systems under different environmental conditions and for different applications. One particularly important application, not yet formally explored is mass trapping to develop completely non-polluting population suppression methods. In addition, future efforts should also focus on incorporating other stimuli such as colors as well as host and bacterial odors to further synergize food lures and baits now available. Furthermore, in support of SIT programmes research should continue to advance in developing practical means to assess the induced sterility in females of wild fruit fly populations.
Page 5 12. Status with respect to publishing the results of the CRP IAEA-Tecdoc-1099 on "Development of Female Medfly Attractant Systems for Trapping and Sterility Assessment" was published in July 1999. In addition over 20 scientific articles to the CRP have been published in peer-reviewed international and national entomology journals.