Cabbage weevil

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Cabbage weevil
Ceutorhynchus assimilis (2007-05-13) .jpg

Cabbage weevil ( Ceutorhynchus assimilis )

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Weevil (Curculionidae)
Genre : Ceutorhynchus
Type : Cabbage weevil
Scientific name
Ceutorhynchus assimilis
( Paykull , 1800)

The Kohlschotenrüssler or Real Kohlschotenrüssler ( Ceutorhynchus assimilis ) is a beetle from the family of weevils (Curculionidae).

features

The beetles are 2.5–3 mm long and appear gray due to their fine hairs. As a member of the Curculionidae family, it has a typical trunk-shaped elongated head. The rails and tarsi are colored black. The larvae reach a length of 4–5 mm. They are legless, yellowish-whitish in color. The head capsule is brown.

Occurrence

The cabbage weevil is widespread across Europe. This species was introduced in North America ( USA , Canada ) and was spotted there for the first time in 1931. Today the species has established itself as a pest in summer rape cultivation in Canada.

biology

The cabbage pod weevil also causes damage in the seed propagation during the production of seeds of the cabbage species , but is primarily a pest in rapeseed cultivation .

The Kohlschotenrüssler overwintered as an adult ( adult ) beetles in the forest edges of the scattering layer at a depth of 0.5-5 cm. The first hatch occurs at soil temperatures of 12 ° C. The important thing is the physiological willingness to hatch, which is favored by rainfall at the end of March / beginning of April. At the beginning of the rapeseed bloom, the beetles fly into the rapeseed fields. At temperatures of over 26 ° C, the beetles become rigid and inactive. To lay eggs, the cabbage weevil bites young pods and covers each with one egg . The occupied pods are marked with a secretion in order to prevent a new occupation by another female. The larva eats two to three ovules. After 35–40 days of development, the larva leaves the pod without it bursting to pupate in the ground . Only one generation is formed each year.

Combat

A chemical control of Kohlschotenrüsslers with insecticides from the group of pyrethroids is common. Edge treatment is usually sufficient to eliminate the economically important cabbage mosquito as a secondary pest, which prefers to stay at the edge of the field.

The parasitoids of the cabbage pod weevil are particularly important . The ore wasp Trichomalus perfectus Walk. infects the larva of the cabbage weevil (host larva) in the third larval stage. This reduces the host larvae's feeding capacity or the larva dies. The parasitic rate is around 32–43%, depending on various factors.

Resistance breeding

In Canada in particular, classic breeding for resistance to the cabbage weevil has been intensified over the last 10 years. By crossing genotypes of Sinapis alba , genetic material could be bred that shows a significant reduction in the infestation by the cabbage weevil. Insect-resistant oilseed rape has not yet been grown in Europe. Only the first results from resistance tests with the spotted cabbage weevil ( Ceutorhynchus pallidactylus ) are available.

Synonyms

In new literature, e.g. B. from Canada, also listed as Ceutorhynchus obstrictus (Marsham). The legality of this renaming is doubted in particular by English taxonomists .

Individual evidence

  1. ↑ HA Cárcamo, L. Dosdall, M. Dolinski, O. Olfert, JR Byers (2001): The cabbage seedpod weevil, Ceutorynchus obstrictus (Coleoptera: Curculionidae) - a review. J, entomol. Soc. Br. Columbia 98, 201-210
  2. ^ A b B. Edner: Biology and ecology of the cabbage pod weevil (Ceutorhynchus assimilis Payk.) With special consideration of the parasitization by Trichomalus perfectus Walker. Dissertation University of Rostock 1983
  3. Jump up ↑ AW Ferguson, M. Solinas, J. Ziesmann, N. Isidoro, IH Williams, P. Scubla, A. Mudd, SJ Clark, LJ Wadhams: Identification of the gland secreting oviposition-deterring pheromone in the cabbage seed weevil, Ceutorhynchus assimilis , and the mechanism of pheromone deposition. Insect Physiology 45 (7), 687-699
  4. ^ IH Williams (2004): Advances in Insect Pest Management of Oilseed Rape in Europe. In: AR Horwitz (ed), Insect Pest Management. Springer Verlag, Berlin, 181–208
  5. ↑ IH Williams: Parasitoids of Cabbage Stem Weevil. In: DV Alford (ed.): Biocontrol of Oilseed Rape Pests. Blackwell Publishing, Oxford 2003, 87-112
  6. ↑ A. Laborius: Investigations on the abundance of the cabbage pod weevil (Ceutorhynchus assimilis Payk.), The cabbage pod mosquito (Dasyneura brassicae Winn.) And their parasites in various places in Schleswig Holstein. Dissertation University of Kiel 1971
  7. ↑ LM Dosdall, LS Kott (2006): Introgression of resistance to cabbage seedpod weevil to canola from yellow mustard. Crop Science 46, 2437-2445
  8. ↑ M. Eickermann, B. Ulber (2010): Screening of oilseed rape and other brassicaceous genotypes for susceptibility to Ceutorhynchus pallidactylus (Mrsh.). , doi : 10.1111 / j.1439-0418.2009.01449.x .
  9. ^ DV Alford, C. Nilsson, B. Ulber (2003): Insect Pests in Oilseed Rape Crops. In: DV Alford (ed), Biocontrol of Oilseed Rape Pests. Blackwell Science, Oxford, 9-41

literature

  • David V. Alford: Biocontrol of Oilseed Rape Pests. Blackwell Publishing, Oxford 2003, ISBN 0-632-05427-1

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