Later chestnut moth
| Later chestnut moth | ||||||||||||
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Late chestnut moth ( Cydia splendana ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cydia splendana | ||||||||||||
| ( Huebner , 1799) |
The Late Kastanienwickler or green oak ( Cydia splendana ) is a butterfly from the family of Winder (Tortricidae), whose caterpillars among others ripe fruits of sweet chestnut develop.
features
The moths have a wingspan of 14 to 22 millimeters. The front wings are ash gray or gray brown. The basal spot is indistinct. In the outer area there is a distinct blackish mark that extends around the eye spot and the subapical area. The hind wings are reddish brown and a little lighter at the base and on the inner edge.
In the fifth and final stage, the caterpillars reach a length of 13 to 15 millimeters. The head is light yellowish brown in color, the prothoracic shield and the anal plate are slightly sclerotized and yellowish. Warts and anal ridge are absent. The abdomen is gray-green or yellowish-white and occasionally tinged lilac-gray. The caterpillar skin and pinacula (small sclerotized areas on the bristle base) have the same color. The anal gland is present. The abdominal bones of the third to sixth abdominal segments have 14 to 21 microscopic hooks that are arranged in a circle. The pusher has only seven to nine hooks.
The pupae are nine to ten millimeters long and brown. On the second to seventh abdominal tergit there are two transverse rows of short, thick spines, on the eighth to tenth segment there is only one transverse row.
Similar species
- Cydia fagiglandana ( Zeller , 1841). The drawing in front of the inner corner and the purple eye spot distinguish Cydia splendana from Cydia fagiglandana .
distribution
The late chestnut moth is common in Europe and Asia Minor , northern Iran , Russia ( Urals ) and Madeira . He colonized deciduous forests with oaks ( Quercus ) and sweet chestnuts ( Castanea sativa ).
Way of life
The life expectancy of the male moths is on average ten to twelve days, the maximum is 21 days. The lifespan of females is shorter than that of males. The females begin laying eggs around 24 hours after mating. On average, around 60 eggs are laid per day for a period of ten days. These are placed individually on the young fruits, with the sweet chestnut they are mainly attached along the leaf veins and in the vicinity of the fruit, whereby neither side of the leaf is favored. The caterpillars hatch after about 10 to 15 days and drill into the fruit at the point of attachment. Only a caterpillar develops in a fruit, which during its development eats the nut more or less empty and fills it with excrement. The simultaneous occurrence of several caterpillars in one fruit is extremely rare, as there is competition within the species. Overall, caterpillars take 35 to 45 days to develop, with five stages going through. Infested fruits look outwardly intact, but fall from the tree early. In this way, the animals get to the ground, where they eat a new 1.5 to 3 millimeter hole in the skin of the fruit and leave it. The adult caterpillars then dig themselves five to ten centimeters into the ground and spend the winter spun in a firm, brown silk cocoon that also contains soil material. Sometimes you can find cocoons in the leaf litter and moss and bark in columns of trees, more rarely, in abandoned bile from gall wasps and other plants Gallen. The winter diapause lasts between 144 days (17 ° C) and 96 days (20 ° C). Pupation takes place next spring and the pupae rest for two to four weeks.
Flight and caterpillar times
One generation is formed per year, which flies in Central Europe from June to July and in Southern Europe from August to September. Flight activity begins at dusk and continues into the night. The main activity is in the hours before midnight. The moths are attracted by the light.
Importance as a pest
The caterpillars attack and destroy the ripe nuts, the pods turn brown and fall off prematurely. Since infested nuts are difficult to detect, infestation also significantly increases processing costs prior to sale. The infestation is usually stronger in dry summers and on poor, stony soils. A monitoring is done by pheromone traps to estimate the number of butterflies. The infestation is determined by taking random samples of the fruit, although the feeding pattern does not show whether it is Cydia splendana or Cydia amplana . To do this, the caterpillars must be bred through to the moth. As a preventive measure, infested fruit casings are quickly disposed of to prevent the caterpillars from digging into the ground. Control measures are tillage in winter and the use of insecticides, if permitted. There have been attempts to combat the late chestnut moth with egg parasites ( parasitoids ). Parasitoids are the braconic wasps Ascogaster quadridentatus , Phanerotoma dentata , Microdus tumidulus and the parasitic wasps Pristomerus vulnerator , Itoplectis maculator , Epirus ventricosus , various Trichogrammatidae and Eulophidae as well as the caterpillar flies Bessa selects and Zenillea roseanae . The mold Paecilomyces farinosus has a pathogenic effect .
swell
- Profile on IEFC.net
- Marco Conedera, Mauro Jermini, Alberto Sassella, Thomas N. Sieber: Harvesting, treating and preserving chestnuts . Leaflet for practice 38, 2004. WSL Birmensdorf, ISSN 1422-2876 (PDF 570kB)
- Ecker et al. a .: Sweet chestnut. Forest tree and fruit trees . Zoppelberg Buchverlag, Ehrenhausen 2006, p. 64f. (without ISBN)
Individual evidence
- ^ A b Arthropods of Economic Importance. (No longer available online.) SA Ulenberg, archived from the original on June 8, 2011 ; Retrieved June 19, 2008 .
- ↑ Cydia amplana (Hübner, 1800). Lepiforum e. V .: Determination aid of the Lepiforum for the butterfly species found in Germany, Austria and Switzerland., Accessed on June 19, 2008 .
- ^ S. Speranza: Chestnut pests in Central Italy . In: G. Salesses: Proceedings of the Second International Chestnut Congress . Acta Horticulturae, Vol. 494, 1999, pp. 417-423. ISBN 90-6605-941-9
