Outbreak of Bemisia tabaci in the United Kingdom
A single outbreak of Bemisia tabaci was confirmed in the United Kingdom in August 1987. It was found as a light but extensive infestation of Poinsettia grown for Christmas marketing. The cuttings had previously been imported from The Netherlands. Bemisia tabaci identification is difficult and is largely based on the puparium. Amongst other features, B. tabaci has a single lens forming a bridge between the groups of compound eyes whereas this is absent from T. vaporariorum.
The life-cycle is similar to that of T. vaporariorum. In British glasshouses development times are expected to be slower and development may even cease during the winter months in warm glasshouses.
As an outdoor pest, its distribution is extensive and it occurs at up to 30° Latitude on either side of the equator. The pest has, until recently, generally been quiescent in winter, even in subtropical glasshouses. There is increasing concern about this pest and pesticide resistance has been reported within several outdoor populations.
B. tabaci has 500 host plants belonging to 77 families. In glasshouses, only tomato, sweet pepper, Poinsettia, Gerbera, Hibiscus and maybe Gloxinia, have been reported as hosts. Poinsettia initially appears to be the most important host for moving the pest in trade.
The pest is also an important vector of at least 20 viruses which may cause damage more severe than direct feeding damage.