Cydalima perspectalis

Cydalima perspectalis
Cydalima perspectalis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Crambidae
Genus:	Cydalima
Species:	C. perspectalis
Binomial name
Cydalima perspectalis (Walker, 1859)
Synonyms
Phakellura perspectalis Walker, 1859 Glyphodes perspectalis Diaphania perspectalis Palpita perspectalis Neoglyphodes perspectalis Glyphodes albifuscalis Hampson, 1899 Phacellura advenalis Lederer, 1863

The Box Tree Moth (Cydalima perspectalis) is a species of moth of the family Crambidae. It is native to eastern Asia (Japan, China, Taiwan, Korea, Russian Far East and India).^[1] It is an introduced species in Europe, first recorded from Germany in 2006, and subsequently from Switzerland and the Netherlands in 2007; from France, Great Britain and Austria in 2009.^[2][3][4] In 2011, the Box Tree Moth has been first recorded from Hungary,^[5] Romania^[6] and Turkey.^[7] It is also known from Slovakia, Belgium^[8] and Croatia.^[9] During the preparation to the 2014 Olympics in 2012 it was introduced from Italy to Sochi with the planting stock of Buxus sempervirens and in the next year it began to defoliate Buxus colchica in large quantities.^[10] In 2013 it was found new to Denmark at several sites in the island of Sjælland.

Larva

Pupa

Brown color variant

Biology

first description WALKER 1859

The species was first described by Walker, 1859.

Description

Eggs are 1 mm in diameter, located under green unattacked leaves. First larvae just coming out from the egg are about 1-2 mm long. Larvae development brings them in four weeks to about 35–40 mm at maximum. There is some shrinkage at the beginning of the nymphosis, pupae are 25–30 mm long, first green with browning longitudinal lines, then more and more brownish. The wingspan of the adult form is 40–45 mm. Two variants are observed, the most common one is mostly white while the other is most entirely light brown.

Cycle

There are two or three generations per year with adults on wing from April/May to September.. In warmest parts of the European importation area, with cold conditions coming late in the year, there might be sometimes four generations per years. The species overwinters as a juvenile cocooned larva (about 5–10 mm long), protected in an hibernarium made of two leaving buxus leaves solidly joined by silk.

Host plant

The larvae feed on the leaves and shoots of Buxus species. Young larvae only eat the upper part of the leaf (leaving the hardest inside structure). The leaves are not destroyed completely but appear as "pealed" in small parallel beats lines, or almost completely. These pealed leaves will eventually die. Old larvae are the most damaging: they massively completely eat the leaves, sometimes leaving however a thin part at the contour and center of the leaf.

Green ball-shaped dejections are left everywhere, mixed by silk, and give an ugly aspect to the infested plant (in addition to a repulsive flavor too, at least for humans).

Natural regulation or predation

Vespa velutina (Asian hornet) in active search of Cydalima perspectalis larvae on an infested box-tree bush.

In the area of origin (Asia) a natural regulation occurs, as witnessed by the non-destructive behavior of Cydalima perspectalis. In the artificial importation area of Europe, the damages are very important because a natural regulation does not occur at a significant level. However, in European areas where the Asian hornet (Vespa velutina) is present prior to Cydalima perspectalis, a certain level of predation by this latter species is observed. This is namely the case in South-West of France, the first place where Vespa Velutina was introduced in Europe in 2004 (Cydalima perspectalis invaded this area in 2012 only). Vespa velutina is able to capture small larvae and larvae preparing for the nymphosis in their cocoon.

Ways of control and fight

Synthetic insecticides (cypermethrin, deltamethrin) are efficient but must be carefully pulverisated also inside the bush, and under leaves. Similar natural pyrethroid insecticides, extracted from Chrysantemus and mixed with colza oil can be used also. In spite of their natural origin, their toxicity is similar to synthetic ones; a serious contact and breath protection is therefore necessary during the treatment. The application of these insecticides must be done in evening in areas where domestic bees or useful insects are presents, to minimize the negative impact.

Bacillus Thuringiensis is a parasitoid which acts on small larvae (leading to muscular paralysis).

Nematodes also have an action on the digestive system of larvae.

Pheromone traps (attracting adults males) are able to prevent impregnation of adult females and therefore control the severity of the damages. A more important proportion of sterile eggs is deposited by adult females . The selectivity of the pheromone is very good and useful indigenous species are not attracted.

Insecticide, Bacillus and nematode treatments must be repeated three times at an interval of about ten days, because they mostly affect young larvae.

Pheromone traps must be in place from March-April till October-November.

References

External links

• European Butterflies and Moths
• Lepiforum e. V.
• Informationen über den Buchsbaumzünsler
• Images

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