Echinothrips americanus introduced in glasshouses in France
Echinothrips americanus has been found for the first time in France, in June 1996. This thrips was observed in a nursery in the Haut Rhin département, on Ficus plants imported from the Netherlands. Another focus was then detected in Burgundy. In 1997, E. americanus was found in again these two regions under glasshouses, as well as in Centre and Poitou-Charente. The French Plant Protection Service has taken eradication measures.
E. americanus is a polyphagous species originating from North America. It is reported as widespread in the east of North America (from south of Canada to Florida, Iowa being a western limit). It is occasionally found in California, Hawaii, Mexico and Bermuda. In 1993, E. americanus was reported for the first time in Europe, in the Netherlands (see EPPO RS 95/093). It was found in nurseries on Araceae (Syngonium, Philodendron, Homalomena) and eradication measures were taken. However, United Kingdom made several interceptions of E. americanus on Dieffenbachia, Hibiscus, Syngonium podophyllum from the Netherlands in 1995/1996 (see EPPO RS 95/175, 96/060). It illustrates the fact that E. americanus can be easily spread in trade. In 1995, this thrips species was also observed in Germany, in the regions of Frankfurt am Main and Kassel on Syngonium podophyllum grown in glasshouses.
Little information is available on the biology of E. americanum. It causes direct damage by feeding but does not transmit viruses. It can attack more than 40 plant genus from 20 families, and it appears that Araceae and Balsaminaceae are particularly attractive to this insect. Among ornamental species, E. americanum can be found on : Anthurium, Asparagus, Bambusa, Cordyline, Dendranthema, Desmodium, Dieffenbachia, Euphorbia, Ficus, Hibiscus, Impatiens, Passiflora, Philodendron, Spathiphyllum and Syngonium. This species needs rather high temperatures for its development, and is most probably not able to survive outdoor in French conditions. From the literature and the experience in France, E. americanum appears as a minor pest causing little damage which can be easily controlled by chemical products. However, considering its presence in several European countries and the importance of the trade of ornamental plants, it is felt that this species may cause problems.
Sources
Reynaud, P. (1998) Echinothrips americanus. Un nouveau thrips des serres importé en France.
Phytoma – La Défense des Végétaux, no. 507, 36-38.