Compte rendu de mission à Campinas du 12-14 décembre 2005
The itinerary of the visit only covered a small proportion of Jamaican coconut plantings though, given the diversity of the sites visited, it provided a fairly good idea of the situation for this crop, and of the potential vector insects present. The damage being caused is extremely serious, and CIB is striving to preserve the crop: introduction of new varieties and planting in zones that are still suitable but little used until now (hilltops and lower mountain slopes where L Y always occurs later). Based on direct observation, the fauna involved (Homoptera Auchenorrhyncha) displays very little variety: 3 species of Cixiidae (including a very scarce Oec/eus), and 2 or 3 Derbidae (a family which is, in theory, not particularly suspect). The samples taken of potential insect vectors, primarily of the two Cixiidae species, have just been examined at the Natural History Museum in Paris (by Paula. Ceotto under the authority of Dr Thierry Bourgoin}. They are indeed Myndus crudus (Van Duzee) and Nymphocixia caribbea (Fennah). Sorne of the Myndus crudus samples will be sent to the University of Arizona (Dr Judith Brown} to study the molecular variability of the species, as certain molecular "races" may be vectors and others not. Sorne of the other Cixiidae samples will undergo phytoplasma diagnosis by PCR at CIRAD. We recommend that the survey carried out during the mission be pursued at both CIB and UWI, so as to gain a clearer understanding of the distribution of potential vector insects in the country and locate other sites suitable for conducting experiments on the controlled reproduction of L Y by insects. lt is very important to search for other hast plants and egg-laying sites of the two species (notably N. caribbea); Pimenta Piece and Bowden Marina are suitable sites for such investigations. lt is possible to carry out L Y transmission trials in Jamaica in insect-proof cages, notably at Pimenta Piece and Bowden Marina. We have made recommendations for implementing such trials, which are essential as much for improving our knowledge of coconut Lethal Yellowing as for leading on to a possible integrated contrai method for this very serious disease. CIRAD's research unit UPR 29 is naturally ready, if the necessary funds can be found, to take part in scientific and technical support missions, setting up and monitoring the trials and studies to be conducted in the search for LY vector insects in Jamaica.