Jacob wort bear

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Jacob wort bear
Jacob wort bear (Tyria jacobaeae)

Jacob wort bear ( Tyria jacobaeae )

Systematics
Class : Insects (Insecta)
Order : Butterflies (Lepidoptera)
Family : Owl butterfly (Erebidae)
Subfamily : Bear Moth (Arctiinae)
Genre : Tyria
Type : Jacob wort bear
Scientific name
Tyria jacobaeae
( Linnaeus , 1758)
Caterpillar on ragwort ( Senecio jacobaea )
Egg clutches
Underside of a butterfly

The Jacob wort bear ( Tyria jacobaeae ), also known as the blood bear or carmine bear , is a butterfly ( moth ) from the subfamily of the bear moth (Arctiinae).

description

The moths reach a wingspan of 32 to 45 millimeters. You can recognize them by the two red dots and the long red lines on the edge of the wing. The basic color of the forewings is black, while the hind wings are bright red.

The caterpillars are about 30 millimeters long. They are ringed bright yellow and black. Their heads are black and they have very little, very long, white hair. In order to protect themselves and also to indicate their toxicity, they imitate the typical black and yellow warning color of wasps ( mimicry ). Due to their color, they are difficult to recognize on the inflorescences of Jacob's ragwort.

Similar species

habitat

This species can be found in dry to slightly damp terrain with a steppe-like character, on meadows, in stone quarries, on forest meadows, dry grassland and on the edges of flowing waters all over Europe .

distribution

In the north, the classic distribution area extends to central Sweden and in the south to the valleys of the Alps , but only up to an altitude of 1,600 meters. They are more common in the south than in the north, but are rare overall.

The species is known globally in other areas as neozoa . She was brought to Australia around 1930 and can also be found in New Zealand , Canada and the USA .

Way of life

The nocturnal animals usually form one generation per year, but incomplete second generations also occur. The caterpillars are gregarious and often sit in larger groups on a plant. In some years they are often found in places. The moths fly from May to June.

Food and toxicity

The caterpillars feed on ragweed ( Senecio spec. ), Mainly the poisonous Jacob's ragwort ( Senecio jacobaea ), to which they owe their name and on which they are not easy to spot due to their color . The poison is bitter tasting pyrrolizidine alkaloids . These alkaloids are liver-toxic to vertebrates and serve to ward off herbivores . However, the pyrrolizidine alkaloids can also help locate the host plant, because they are scented by the specialized predator, the Jacob wort bear, in order to find the herb to lay eggs. Most of the pyrrolizidine alkaloids are not toxic to the Jacob wort bear. The caterpillars ingest it while they are eating and store it , becoming poisonous to other animals without being harmed themselves. Sometimes they also eat coltsfoot ( Tussilago farfara ) and butterbur ( Petasites spec. ).

development

The females lay their eggs in small groups on the underside of leaves. The caterpillars are found from July to August. To overwinter, they pupate on the ground or near the ground in a cocoon. The moths then hatch in the next May to June.

literature

  • Günter Ebert: The butterflies of Baden-Württemberg. Volume 5: Moth III. Ulmer Verlag, Stuttgart 1997, ISBN 3-8001-3481-0 .

Web links

Commons : Jakobskrautbär  - Album with pictures, videos and audio files

Individual evidence

  1. ^ Günter Ebert: The butterflies of Baden-Württemberg.
  2. Tyria jacobaeae at lepidoptera.butterflyhouse.com.au (accessed July 21, 2019)
  3. a b Dellbrücker Heide Retrieved June 11, 2012
  4. ^ WH Gera Hol, Mirka Marcel, Johannes Avan Veen, Ed van der Meijden: Root damage and aboveground herbivory change concentration and composition of pyrrolizidine alkaloids of Senecio jacobaea. In: Basic and Applied Ecology , 5, No. 3, 2004, pp. 253-260, doi : 10.1016 / j.baae.2003.12.002 .
  5. Mirka Macel, Klaas Vrieling:: Pyrrolizidine alkaloids as oviposition stimulants for the cinnabar moth, Tyria jacobaeae. In: Journal of Chemical Ecology , 29, No. 6, 2003, pp. 1435-1446 ( PDF ).
  6. Mirka Macel, Peter G. Klinkhamer, Klaas Vrieling, Ed van der Meijden: Diversity of pyrrolizidine alkaloids in Senecio species does not affect the specialist herbivore Tyria jacobaeae. In: Oecologia , 133, No. 4, 2002, pp. 541-550 ( PDF ).
  7. Werner Szramka: Pupation of the Jacobskraut bear caterpillar. Retrieved on March 19, 2020 (individual observation documented by photos).