Black Arches
Nun moth (Lymantria monacha ), male
The nun moth (Lymantria monacha ) is a butterfly (moth ) from the subfamily of Trägspinner ( Lymantriinae ) within the family of cutworms ( Noctuidae ).
- 7.1 Notes and references
- 7.2 Literature
Features
The moths reach a wingspan of 30 to 50 millimeters. The females are significantly larger than the males. The base color is white with many different thicknesses and jagged dark bands and spots. Every now and then also appear quite black individuals. With a mass increase as much as 50 percent of the new generation are almost black. The dark shapes have a certain similarity with the males of the gypsy moth. The hind wings are of a beige color and have black Saumpunkte on.
♂
Similar Species
- Gypsy moth ( Lymantria dispar ) (Linnaeus, 1758)
Habitat
One finds the nun in dense spruce and pine forests. Partially mixed forests also serve as a biotope. The population varies from year to year. In an approximate cycle of three to five years there will be a mass propagation.
Flight and caterpillar time
The flight time of one generation is between July and early September.
Way of life
The track begins in late April and ends in June. The nest is placed in small packages under bark or smooth tree trunks under lichens. Most often this is at the bottom of a tree, only when outbreaks can also find eggs in the crowns. A female lays up to 300 eggs, each pile can contain 20 to 100 eggs. The newly hatched caterpillars remain - weather permitting - a few hours to days together. This operation is called by the foresters "mirror". After the caterpillars climb into the crowns of the trees and spread that way. There is wind, the caterpillar draws a thread that can be down it and into the wind on a different tree. Thus, the intraspecific competition is largely avoided. This also contributes to the female part, because it searches for oviposition targeted not yet infested trees.
Food, mode of action of mass populations
The caterpillars feed preferably of Norway spruce ( Picea abies) and pine (Pinus sylvestris). In addition, be as caterpillars feed plants silver fir (Abies alba), European larch (Larix decidua), aspen (Populus tremula ), hornbeam (Carpinus betulus ), beech ( Fagus sylvatica), English oak (Quercus robur), cultivated apple (Malus domestica) sycamore maple (Acer pseudoplatanus), bilberry (Vaccinium myrtillus) and bog bilberry ( Vaccinium uliginosum ) called. In spring, the animals gnaw at the first buds, and later on the needles. A caterpillar eats about 200 pine, or 1000 Fichtennnadeln and damaged during biting as many again. Spruce and pine trees die at 70 percent at 90 percent needle loss. Risk is also increased by the malicious disposition towards secondary infections caused by longhorn beetles, bark beetles, fungi or other pathogens. Therefore, outbreaks of the nun can cause great damage in forestry.
To prevent the proliferation of the nun, infected trees should be removed immediately. Non- site-specific forest plantations increase the risk and are more affected by gradations, so the conversion of such forests is advisable to go to thin mixed stands. To prevent the population development should be constantly under surveillance. If such prophylactic measures do not come into question, such as outbreaks of chemical or biological measures can be countered, so with the use of poisons, or of antagonists such as viruses, bacteria or parasitic wasps.
Dissemination
The type is from the north of the Iberian Peninsula over western and central Europe (including southern England ) to the temperate zone of East Asia spread. The northern boundary of the distribution area extends from Oslo, Uppsala, St. Petersburg, Perm and between 43 and 57 degrees north latitude to Japan. The southern boundary extends from central Spain, Corsica, the Dalmatian coast, through northern Greece and the European part of Turkey to the Black Sea.