Violet oil beetle
| Violet oil beetle | ||||||||||||
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Violet oil beetle, female ( Meloe violaceus ) |
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| Scientific name | ||||||||||||
| Meloe violaceus | ||||||||||||
| Marsham , 1802 |
The violet oil beetle or violet or blue Mayworm ( Meloe violaceus ) is a beetle from the family of the oil beetle (Meloidae).
features
The beetles are 10 to 32 millimeters long, while the females are slightly larger than the males. The head of the animal is large and severely pinched. The hind wings are completely regressed, the beetles are therefore unable to fly. Their bodies are stocky and blue to violet-blue, rarely black-blue. The head and pronotum are very finely dotted with matt dotted spaces. These body sections are somewhat shiny compared to the rest of the body. The wings are significantly shorter than the abdomen and gape at the end strongly apart, while they overlap basally - quite unusual for beetle elytra . The antennae of the males are clearly bent in the middle.
Similar species
- Black-and- blue oil beetle ( Meloe proscarabaeus ). While the base of the pronotum is indented in the violet oil beetle, it is straight in the black and blue oil beetle.
Occurrence
The animals occur all over Europe , also in the far north and east to Siberia . They live on sunny, dry terrain with flowering plants, because their way of life makes them dependent on bees.
Way of life
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The diurnal animals feed on parts of plants, which you can see in their green droppings. In case of danger, to deter enemies such as ants or ground beetles, they release a yellow defensive secretion from their knee joints , which contains the highly toxic chemical compound cantharidin .
After mating, a female lays 2,000 to 10,000 eggs in a self-dug cave. The larvae develop via hypermetamorphosis , so the various larval stages are designed differently. The three-millimeter long three-clawed claws ( Triungulinus ) hatch from the eggs . These climb a flower, where they cling to an approaching insect as a potential host animal. Only if they catch a solitary wild bee (e.g. a sand bee or a fur bee ) do they have a chance of survival. Should the larva accidentally choose a honey bee , it will die in the beehive. This explains the high number of eggs laid as the loss rate is very high. This stage of the life cycle is a diffusion stage. The larvae then live parasitically in the nests of their hosts. After they have eaten the egg and then the mixture of nectar and pollen from the bee's pantry, they leave the nest. They shed their skin one more time and are then more maggot-like and barely mobile, with receded legs. These larvae pupate and the finished beetle hatches from the pupa between March and May ("May worm").
Individual evidence
- ↑ Identification key for flora and fauna in Rhineland-Palatinate, species group: beetles in and around Rhineland-Palatinate
- ^ Fauna Europaea - Distribution of Meloe violaceus
literature
- Jiři Zahradnik, Irmgard Jung, Dieter Jung et al .: Käfer of Central and Northwestern Europe , Parey, Berlin 1985, ISBN 3-490-27118-1
