Mineuse of the sheets of allium

The Napomyza gymnostoma is a devastating Mouche of the plants of the kind Allium (Poireau, garlic, chive, Oignon, etc) in Europe in its larval form. Its Larve is called Mineuse sheets of Allium

Description

NR. gymnostoma winters in the form of Pupe S attached to fabrics of the Plante. At the beginning of spring, adults emergent. The adults are small Mouche S 3 mm length grisâtres, with a yellow famous person. The length of the wings varies from 2,9 mm for the males to 4,0 mm for the females. The legs are sunk with yellowish articulations.

Propagation

The observations made during the 20 last years suggest that mineuse Feuille S of Allium must be regarded as new a devastating important of the Oignon S and Poireau X, and that one can expect to see his importance increasing.

The damage on the cultures of Allium caused by Napomyza gymnostoma was announced by a growing number of European countries. This ravageur was described for the first time in 1858 in the area of Poznan (Poland). In 1976, this species was announced to the Denmark, Sweden, Poland and in the Mediterranean basin, but no damage was observed.

Since the Years 1980, the mineuse one of the sheets of Allium became a ravageur of the Allium in several countries for reasons which remain unknown, initially in Europe of the East and more recently in Western Europe. Today, this ravageur is largely widespread in Europe:

Damage

This parasite more particularly attacks the Poireau, but also the chive and on a scale the less Oignon, the garlic and the shallot. The Larve S of NR. gymnostoma mine the stems and the Bulbe S of Allium , which become soft and sensitive to the fungic or bacterial infections. Frequently, of the severe deformations of the sheets and the split stems are observed. The females make many punctures of food, on the sheets. These punctures are the first sign that the Mouche S are active.

The eggs are laid in vegetable fabrics, usually at the base of the sheets. The larvae mine the sheets, while going down in the stem, and finally towards the Bulbe, then transform themselves into nymph at the end of their galleries. During the summer, the ravageur mountain pasture in the form of nymph inside the plants. Another generation of adults emerges at the end of the summer, beginning of the autumn. In spring, the damage is observed after the first flight of the adults. On the Poireau X for example, which are usually small at this period of the year, some Larve S can kill a plant, so that an infested field can quickly present a great number of missing plants. In autumn, the plants are larger and tolerate levels of higher populations. Even if no figure is given, the losses caused by NR. gymnostoma are considered of economic importance.

It is announced in Serbia, that the presence of approximately 20 mineuses by Plante can lead to its destruction. Moreover, the presence of Larva S in the young plants of Onion and Poireau can make them unsaleable. The adults can fly, but more studies are necessary over the periods and the distances from vol. There are no data on the possible role of Bulbe S infested in the dissemination of the Insecte S. the Allium are largely cultivated in the area and in many European countries, NR. gymnostoma is mentioned like a devastating emerging and economically important.

Fight

Other studies are necessary on the measures of struggle (rotations, vegetable remains destruction, fights chemical).
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