Le travail de M. C. Richard Edwards, professeur auprès de la Purdue University (États-Unis) illustre le mode d'intervention original des experts invités travaillant avec la FAO dans le cadre du Programme d'experts invités. Le professeur Edwards, spécialiste de renommée mondiale de la chrysomèle des racines du maïs, Diabrotica virgifera virgifera LeConte, a participé en qualité de consultant chef de file dans le cadre du Programme de coopération technique à un projet sur cet insecte dont la mise en place a été demandée par la Bosnie-Herzégovine, la Croatie, la Hongrie et la Roumanie. L'infestation menace ces quatre pays d'Europe centrale et s'étend à d'autres zones. Tout au long de sa mission, M. Edwards a travaillé au Département de protection phytosanitaire de l'Université des sciences agronomiques de Gödölló (Hongrie).
La labor que lleva a cabo C. Richard Edwards, de la Universidad Purdue (EE.UU.), sirve para ilustrar de qué forma innovadora trabajan los expertos visitantes con la FAO dentro del Programa de expertos visitantes. Edwards, experto mundial en la tortuguilla o coquito pintado de la raíz del maíz, Diabrotica virgifera virgifea Le Conte, participó como consultor principal en un proyecto del Programa de Cooperación Técnica (PCT) sobre dicho gusano a solicitud de Bosnia-Herzegovina, Croacia, Hungría y Rumania. Las infestaciones causadas por este insecto constituyen actualmente una amenaza para esos cuatro países de Europa central y su población se está extendiendo a otras zonas. Durante su misión con la FAO, el experto tuvo como base el Departamento de Protección Vegetal de la Universidad Gödölló de Ciencias Agrónomas, Gödölló, Hungría.
The work of C. Richard Edwards, a professor at Purdue University in the United States, illustrates the innovative manner in which visiting experts work with FAO under the Visiting Experts from Academic and Research Institutions Programme. Edwards, a world expert on the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, participated as lead consultant in a Technical Cooperation Programme (TCP) project on WCR at the request of Bosnia and Herzegovina, Croatia, Hungary and Romania. Infestations of
Western corn rootworm pheromone traps being removed in Romania |
The western corn rootworm is the most significant insect pest affecting maize cultivation in the midwestern United States. First identified in Europe in 1992 in a field near the main airport of Belgrade, Federal Republic of Yugoslavia, it is the most serious crop pest introduction into Europe since the discovery of the Colorado potato beetle in Germany in 1877.
WCR is spreading rapidly outwards across Central and Eastern Europe. In addition to Yugoslavia, Bosnia and Herzegovina, Croatia, Hungary and Romania, it has also been found in northwestern Bulgaria, northeastern Italy and northern Montenegro. Based on the present rate and direction of its spread through the infested countries, WCR will probably find its way into other areas of Europe within the next few years. This is likely to cause economic hardship to farmers by raising their production costs and will pose greater environmental problems through the increased use of insecticides directed against this pest.
WCR larvae and adult beetles can damage maize plants, although the most significant damage occurs from larvae feeding on the roots. Larval damage can reduce the amount of water and nutrients supplied to plants, thus impacting yield. Additionally, extensive root damage makes plants susceptible to lodging. Plants that have fallen over are difficult to harvest, especially by machine, and harvest losses occur. The adult beetles can also interfere with the pollination process.
Yield losses approaching2 tonnes per hectare have been reported across about 14 000 km2 of northern-central Yugoslavia. This number corresponds with losses seen in the midwestern United States where the cost for chemical control, combined with the value of crop loss, has been estimated at approximately US$1 billion per annum. Within the next one to three years WCR
C. Richard Edwards (third from right) with technical project staff in Romania |
The TCP project was formulated by FAO's Plant Protection Service (AGPP) in close collaboration with the participating countries and Professor Edwards. Its aim was to safeguard food security in the region by helping to achieve profitable and environmentally safe maize production through the implementation of short- and long-term containment and control programmes. Awareness creation and training of national researchers, extension personnel, farmers and pest managers to deal with this new pest were important components of this project. Links were established with institutions in the United States that are developing and field-testing areawide WCR control programmes that are less dependent on insecticides.
The project activities were coordinated by a regional and a national coordinator in each participating country. Edwards provided technical support to the coordinators and guided project activities in close collaboration with AGPP and FAO's Subregional Office for Central and Eastern Europe in Budapest, Hungary. The field activities of the project were organized in three phases: the establishment of a permanent monitoring network for WCR; the implementation of an intensive trapping containment and control programme for the pest; and the evaluation of an areawide pest management programme based on a new, more ecological approach.
In the first phase of the project, Edwards and his team used a Hungarian pheromone-based trap which attracts WCR male beetles for population monitoring. Traps were positioned in permanent locations in Croatia, Hungary, Romania and Bosnia and Herzegovina. The traps were monitored at regular intervals between the beginning of adult emergence in late June and October. During this period, adult beetles feed, mate and lay eggs. Although they are not official TCP countries, Bulgaria, Slovenia, Slovakia, Austria, the Czech Republic and Ukraine were provided with traps for monitoring.
In phase two, a second type of "female-friendly" trap, which also attracts males, was used together with the Hungarian pheromone trap. These two types of trap were placed in Croatia, Hungary and Romania along the leading edge of infested areas bordering Yugoslavia, to capture both sexes. The purpose of this trapping strategy was to determine the feasibility of reducing or even removing WCR populations from an area over time.
The final phase of the project tested the impact in Hungary of a new areawide WCR pest management programme that is also being tested in the United States. In this programme, Slam® (a registered trademark containing a combination of cucurbitacins as a feeding stimulant and a carbaryl as the toxicant) was used to control the adult beetles prior to egg laying. This contains only one tenth of the full dose of insecticide that would normally be applied and aims at preventing the female adult population from laying enough eggs to impact the following year's maize crop.
Preliminary data show that the TCP project has been very successful and that most of the objectives have been met. Although containment was one of the goals, the geography of the region is such that the spread of WCR is likely to continue. Edwards and the other members of the TCP project staff have proposed there should be a follow-up, donor-assisted project.