For several days, in Iași, we can notice how various ornamental plants, hedges, roses, vine and fig shoots are covered by a whitish cotton-like fluff. Certainly, it is not about cotton. And the curiosity does not stop here.
At first sight, it looks like woolly plant louse (Eriosoma lanigerum), known precisely for the production of the so-called wool. But, at a closer look at my fluffy, I realized I was wrong. The larvae watched jumped as flees which does not constitute a feature for the woolly plant louse.
If I take a pause and rethink the matter, about 3 weeks ago, in the evening I noticed small brown butterflies in the garden which looked as if they reached adulthood.
Looking up in the literature, my surprise was not quite small, since it is possible that Metcalfa pruinosa had reached Iași and this is not all right, we are dealing with a foreign invasive species which “represents a major threat to biodiversity. […] The consequences of ecological, economic and social nature are severe and require a harmonized reply to stopping the spread of invasive species across EU”, as Mr Stavros Dimas stated, EU Commissioner for Environment.
Metcalfa pruinosa, a species of cicada originated from the East part of North America, was first identified in Italy in 1979. On the Romanian territory, it was first signalized in Constanța and Timișoara in 2009. A polyphagous species, Metcalfa pruinosa has a wide range of host plants (over 200), from voluntary plants to fruit trees and, especially, ornamental shrubs and trees.
Regarding the economic impact of this species, Metcalfa purinosa may cause plant debilitation affected by various factors (such a late frost) and when the attack is massive, it may very well destroy the plant.
This cicada secretes a series of sweet substances which favour the emergence of various types of fungus which also add an aesthetic discomfort.
If we are to find a positive feature of this species, by its sweet secretions produced by larvae, the plants under attack can become a food source for bees.
If it comes true that the pest spotted in Copou neighbourhood from Iași is indeed Metcalfa pruinosa, the specialized offices of the local public administration are compelled to take immediate phytosanitary measures to limit as much as possible the attack and control the pest. In case these measures are not enforced, the vineyard basin of Iași is under threat and the losses will be major not this year only, but the next one as well.