Surveys carried out in France on Thrips palmi
In 1996, surveys have been carried out by the French Plant Protection Service on Thrips palmi (EPPO A1 quarantine pest), both within the country and at points of entry.
At the national level, two types of surveys have been done: on Ficus plants originating from the Netherlands sold on markets, shops and garden centres, and on host plants of T. palmi grown in France with emphasis given to tomato, cucumber, melon and chrysanthemum. In total, 521 checks have been made in 38 départments, using plant beating or extraction funnels (Berlèse); the thrips found were then identified in the laboratory. This extraction technique is the most effective to detect thrips on plant material. The results of these surveys have confirmed that T. palmi is absent from France, no single specimen having been found either on Ficus or on other crops. Among thrips species identified on the inspected plants, Frankliniella occidentalis (EPPO A2 quarantine pest) was dominant on most crops, T. tabaci was also present but to a much lower extent, and other species were found sporadically.
Further studies have been made to try to identify the main pathways of entry for T. palmi. Data were gathered from the literature on its potential host plants and on interception records, but also from practical experience of phytosanitary checks made on imports at the airports of Paris. Consignments were visually inspected, samples were taken to be analysed by using extraction funnels (Berlèse) and thrips species were identified in the laboratory (infested consignments were of course intercepted). Three main pathways have been identified: 1) cut flowers of orchids from Thailand and Singapore, 2) fruits of Solanum melongena, leaves of Cucurbita maxima and Sechium edule from Mauritius, 3) fruits of S. melongena, Momordica charantia from Dominican Republic. Other vegetables like Basella rubra from Viet Nam; Capsicum frutescens and aubergines from Mauritius, aubergines and cucumbers from Dominican Republic, aubergines from Thailand are also considered as presenting a risk. Vegetables imported from the French overseas departments Guadeloupe and Martinique (in both of which T. palmi is present) have not presented any problems. Concerning orchids, inspections have also been made on rooted orchids, and one Dendrobium plant from Thailand was found infested. It is suggested that the import of rooted orchids with flowers from countries where T. palmi occurs should be prohibited. In addition, checks were done on cut flower orchids carried by passengers and infestations were also found.
Sources
French Plant Protection Service, Paris, 1997-01.