Twelve-point asparagus beetle

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Twelve-point asparagus beetle
Twelve-point asparagus beetle (Crioceris duodecimpunctata)

Twelve-point asparagus beetle ( Crioceris duodecimpunctata )

Systematics
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Leaf beetles (Chrysomelidae)
Subfamily : Swiss beetle (Criocerinae)
Genre : Crioceris
Type : Twelve-point asparagus beetle
Scientific name
Crioceris duodecimpunctata
( Linnaeus , 1758)
Front view
Side view

The twelve-point asparagus beetle ( Crioceris duodecimpunctata ) is a beetle from the family of leaf beetles (Chrysomelidae). It occurs as the second most important pest on asparagus species . Other variants of the German name are colloquially just asparagus beetle, twelve-point asparagus beetle and twelve-point asparagus beetle.

features

The beetle becomes 5 to 6.5 millimeters long. The head, pronotum and elytra are evenly colored bright orange-red. The scutellum is black. There are six black dots on each of the wing covers, which are more than twice as long as they are wide. Sometimes the size and number of these points varies. The antennae , like the ends of the legs ( femora ) and splints ( tibia ), as well as the tarsi are colored black. The forehead is provided with a longitudinal furrow.

Occurrence

The animals are found in large parts of the Palearctic and, among other things, on the British Isles . The species is absent from Fennoscandia and was introduced to North America in the 19th century . The animals fly from April to October.

Way of life

The twelve-point asparagus beetle only develops on asparagus plants. The beetles overwinter near the asparagus plants or on plant remains and come back from there in May to the asparagus plants. The females lay 70 to 100 of their turquoise eggs individually flat on the leaves of the asparagus plants, but they are especially placed on flowers and their early stages. The larvae hatch about ten days after laying eggs. They are ocher in color and reach a length of about seven millimeters. The larvae live on the plants for about two weeks when they are ripe. The development time from oviposition to adult is three to five weeks. Two generations can be formed in Central Europe. The next generation is particularly harmful in seed cultivation because it eats the fruits of the asparagus and lowers the seed yield. The second generation larvae can be found from August to September. Pupation takes place in the ground, the pupa already has a similar color to the later adult beetle.

Harmful effect and control

Larvae and beetles damage asparagus by feeding on the whole plant. The species is with the common asparagus ( Crioceris asparagi ), which causes very similar damage, the second most important pest in agricultural asparagus crops, but occurs somewhat less frequently than the common asparagus. After the larvae hatch, empty egg pods remain on the shoot tips, which are viewed as pollution and reduce the value in the sale of green asparagus in particular.

So that the beetles cannot hibernate in plant remains, the plants are completely removed or incorporated after they have moved in. As long as the shoots do not get too big during and after the stinging time, the dams can also be protected from the beetles with tunnels made of fleece or fine nets. These measures also protect against the asparagus chickens. In order not to promote reproduction, asparagus seedlings are removed from seeds from the previous year as well as overlooked, small or premature asparagus shoots. The twelve-point asparagus beetles, like asparagus beetles, are combated preventively if there are several beetles per plant or increased larvae. Effective are the pyrethroids and the bacterium Bacillus thuringiensis spp. tenebrionis . It is also possible to use the active ingredient azadirachtin . In the home garden, the plants can be treated with soap, but this is less effective.

supporting documents

Individual evidence

  1. a b c J. Zahradnik et al .: Käfer Mittel- und Nordwesturopas , Verlag Paul Parey, Berlin, ISBN 3-4902-7118-1 , 1985, p. 279.
  2. a b c d e G. Crüger et al .: Plant protection in vegetable cultivation , 4th revised and expanded edition, ISBN 3-8001-3191-9 , 2002, p. 243.
  3. JA Boisduval: Essai sur l'entomologie horticole: comprenant l'histoire des insectes nuisibles a l'horticulture avec l'indication des moyens propres a les éloigner ou a les détruire et l'histoire des insectes et autres animaux utiles aux cultures , Librairie d'horticulture de E. Donnaud, 1867, pp. 476-477.
  4. ^ R. Fritsche: Die Pflanzen, Vorrats- und Materialschädlinge Mitteleuropas - with references to countermeasures , revised edition, Gustav Fischer Verlag, Jena, ISBN 3-3346-0531-0 , 1994, p. 185.
  5. a b c d e f A. Kahrer and M. Gross: Vegetable pests - detection, way of life, control , Österreichischer Agrarverlag, Leopoldsdorf, ISBN 3-7040-1569-5 , 2002, pp. 79–81.
  6. a b c J.J. Cebenko, LA Gilkeson and DL Martin: Insect, disease & weed ID guide: find-it-fast organic solutions for your garden , Rodale, ISBN 0-8759-6867-8 , 2001, p. 31.
  7. a b Y.H. Hui, S. Ghazala, DM Graham: Handbook of vegetable preservation and processing , CRC Press, ISBN 0-8247-4301-6 , 2003, pp. 667-668.

literature

  • Karl Wilhelm Harde, Frantisek Severa and Edwin Möhn: The Kosmos Käferführer: The Central European Beetles. Franckh-Kosmos Verlags-GmbH & Co KG, Stuttgart 2000, ISBN 3-440-06959-1 .
  • Jiři Zahradnik, Irmgard Jung, Dieter Jung et al .: Beetles of Central and Northwestern Europe. Parey, Berlin 1985, ISBN 3-490-27118-1 .

Web links

Commons : Twelve-Spot Asparagus Beetle  - Album with pictures, videos and audio files