Spiral horn bees
| Spiral horn bees | ||||||||||||
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Flat tooth spiral horn bee ( Systropha planidens ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Systropha | ||||||||||||
| Illiger , 1805 |
The spiral horn bees ( Systropha ) are a genus of bees within the family of Halictidae . The genus is restricted to the Old World, around 25 species have been described worldwide, four species occur in Europe and two in Central Europe. There the genus is endangered by habitat destruction .
features
The bees are 8 to 11 millimeters long. Her body is colored black, and there are no light-colored hair ties on the abdomen. The head is very small in relation to the pronotum and the short, hairy abdomen. The females can be recognized by their characteristic tufts of hair on the sides of the abdomen. However, the pollen is transported with the entire, specially provided hair of the abdomen, whereby the abdomen of the females is completely covered with pollen. In comparison, the hairbrushes on the thighs and rails transport very little pollen. The antennae of the females are thickened club-shaped. The last five antennae of the males, on the other hand, are bent triangular, which is why the genus got its German name. Your abdomen is also noticeably profiled. The identification of the species within the genus is difficult; the two Central European species cannot be distinguished from one another in the field based on their appearance.
Way of life
The animals fly in Central Europe in one generation per year from July to August. The females dig their nests in the ground in flat to sloping, vegetation-free to sparsely overgrown areas. The nests are often found in sandy places, where they are laid out solitary, but often in large aggregations. They are up to 50 centimeters deep and lead initially at an angle, then vertically into the ground. The five to eight oval cells are aligned horizontally and are individually located at the end of about one centimeter long side aisles branching off at right angles from the main passage. After the cells have been closed, these passages are filled with excavation of the main passage. One egg per cell is laid on an orange, slightly damp pollen ball. The larvae pupate in a brown cocoon , which is made up of two layers, which are separated by a thin, loose web. The pupa hibernates.
The two Central European species collect pollen oligolectically on winches ( Convolvulus ), especially on the field winch ( Convolvulus arvensis ). The females fly to the flowers in a swoop and only linger there briefly. Males patrol winches in search of females. The adults spend the night in the blossoms of the winds or cling to stalks with their mandibles.
The Biastes brevicornis belonging to the power bees is known as the cuckoo bee of the genus.
Species (Europe)
- Systropha chrysura Perez, 1905
- Systropha curvicornis (Scopoli, 1770)
- Systropha grandimargo Perez, 1905
- Flat-tooth spiral horn bee ( Systropha planidens ) Giraud, 1861
supporting documents
Individual evidence
- ↑ E. Scheuchl, W. Willner: Pocket dictionary of the bees of Central Europe . Quelle & Meyer, 2016, ISBN 978-3-494-01653-5 , pp. 841-844 .
- ↑ Systropha. Fauna Europaea, accessed August 22, 2010 .
literature
- Andreas Müller, Albert Krebs, Felix Amiet: Bees. Central European species, way of life, observation. Naturbuch-Verlag, Augsburg 1997, ISBN 3-89440-241-5 .
