In these days of May on many ornamental trees along avenues and public gardens, especially in Milan, it is possible to notice a sort of “lace” formed by many white rings hanging from the branches: it is ladybugs with cotton filaments (Takahashia japonica)a new invasive alien insect of the Coccidae family, accidentally imported from Asian countries. Such phenomena are increasingly frequent especially in areas where the traffic of goods and passengers is very high: in this case, “the invader” is quite evident and under the eyes of all because it affects ornamental plants in an urban environment. For this reason, in regions such as Lombardy where there are international airports, a special has been established Airport phytosanitary control service To systematically inspect the goods and luggage of passengers arriving from third countries. Despite the controls, the entrance to Allocetone species It is a very worrying problem of growing interest.
What is the Takahashia japonica
The cochineal with cotton filaments (Takahashia japonica) is an insect belonging to the coccidae, a family made up of Ben 1160 very feared species because they are all phytophagus (they feed on plant parts) and cause serious damage to plant essences and agriculture. Takahashia japonica, As the name also indicates, it is originally from Japan, but it is also widespread in China, South Korea and India, associated mainly with mulberry plants. Was reported for the first time in Europe in 2017, Just in Italy in Cerro Maggiore in the province of Milan and a short time later it was also found in Croatia. Since then theinvasion especially in the north-east of the peninsula.
It is a polyphagist insect, that is, it feeds on a large number of plant essences from many plants (for example maple, tire, mulberry, Judah and Bagolaro tree) and for this reason it can damage trees of avenues and gardens. It is a partnership species (the egg develops without being fertilized) and in Italy develops with one generation per year. From the end of April to May the females lay down up to 5000 eggs Within protective wraps (ovisacchi), extremely resistant to the weather, with a ring shape: they are precisely those white and rubbery “lace” that can be observed on the branches of the trees in spring.
From the eggs the young insect comes out at the Ninfa stadium that moves to the lower page of the leaves where the sucks vegetable lymph Throughout the summer, weakening and gradually dissecting the plant. In autumn, the nymphs to their second stage of development, return to the branches to winter. In the month of April of the following year, in just ten days, the wetsuit took place at the adult reproductive stage.
What can cause the spread of cotton mealybug
Fortunately this insect It is not dangerous neither for humans nor for animals, but it can create obvious damage to plants. In fact, it can occur with rods of branches and parts of the hair. The wind, the means of transport or even residues of pruning already infested are promoted the spread of the parasite with great speed.
How to counteract the spread of the Takahashia japonica
Since to today There is no specific insecticide For this parasite, the diffusion with various precautions must be checked: pruning and immediate destruction of the infested branches; use of mineral oils at the moment of vegetative recovery of the plant, for hit the wintering nymphs early; possible use of Antagonist insects like ladybug Adalia bipunctated .
At the moment, however, the most useful and important thing to do is report his presence to the phytosanitary service regional.
