Metcalfa pruinosa Say (Insecta: Homoptera: Flatidae): a new pest in Romania.
A new invasive species has been detected in Romania in the past two years. The scientific name of this species is Metcalfa pruinosa Say (1830), also known as citrus flatid plant hopper. Its importance as a pest species is assessed it in different ways by specialists. In North America (where the insect comes from) minor damages have been reported, with insignificant economic importance, while in Europe it is considered a very important invasive species, due to its high population density and to its wide range of host plants. Another important aspect is the damage produced by this insect, especially the damage they cause to agricultural plants. Currently, the invasive species is only present in some European countries, but there is a tendency of rapid spread to uninfested areas. A number of studies have been conducted in Europe on M. pruinosa Say, on its distribution, morphology, biology, ecology, mating behaviour, range of host plants and control measures. Because this species has only recently been detected in Romania, the researchers have only begun to monitor it. Actually, isolated research has been run in two places where the insect appeared. That is why we considered it necessary to focus the information related to M. pruinosa Say at a national level, thus promoting the development of a national monitoring system. Another aspect that we want to emphasize in the present paper is the range of host plants, which differs greatly from one country to another, but also from county to county within the same country. We noticed that in the west of Romania the insect feeds on a wide range of host plants (herbaceous or woody, agricultural or ornamental plants). Taking all of the above into consideration, we find it necessary to take measures against its spreading, especially in the areas that have not been infected yet. Until now, the presence of M. pruinosa in Romania has not been mentioned at European level; one of the reasons might be that the phytosanitary quarantine units have not issued any official statement on this matter.