Seven-point ladybug
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Seven-spotted ladybird ( Coccinella septempunctata ) |
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| Coccinella septempunctata | ||||||||||||
| Linnaeus , 1758 |
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The seven-point ladybird or seven-point ladybird ( Coccinella septempunctata ) is probably the best-known species from the ladybird family (Coccinellidae).
features
The beetles are 5.2 to 8 millimeters long and have a slightly elongated, strongly arched and round body. The wings are colored red and each have three black dots. A seventh black point, flanked at the front by two white, triangular spots, can be found on the label ( scutellum , divided in the middle in the upper picture). The pronotum is colored black except for the white front corners. These also extend as a narrow seam on the underside of the pronotum. There are two white dots on the inside of the black compound eyes on the black head .
Outwardly, the males hardly differ from the females. With the help of a microscope, the males can be recognized by a tuft of hair on the penultimate sternite .
Occurrence
The beetles are very widespread and common throughout the Palearctic ( Europe , Asia , North Africa ) and also in North America . They inhabit both open and wooded areas, but the presence of aphids is mandatory. The animals usually sit on leaves near leaf or scale insect colonies, on which they feed. You can find them from spring to late autumn.
Coccinella septempunctata , along with Adalia bipunctata, was one of the two most common ladybird species in Europe, but it has been increasingly displaced by the invasive species Harmonia axyridis since it was introduced in the 1980s. Coccinella septempunctata , like other European ladybird species, but in contrast to Harmonia axyridis, has no immune defense against the microsporidia it harbors in the hemolymph . In contrast to Adalia bipunctata , for example , the populations of the seven point have stabilized. According to a study by the Julius Kühn Institute in Kleinmachnow , Coccinella septempunctata benefits more than Harmonia axyridis from increasingly warmer summers, whereby it can convert larger amounts of aphids into fat reserves better than the latter. According to the entomologist Werner Schulze from the Naturschutzbund Deutschland , Coccinella septempunctata can be found more frequently in Germany again in 2015, in contrast to Adalia bipunctata .
Way of life
The beetles overwinter in colonies made up of a large number of animals on the ground between moss, grass or leaves. Often, however, they also come to buildings, where they usually die because of the dry and warm air. After mating, the females lay about 400 eggs about 1.3 millimeters long on parts of the plant that have been infected by aphids. These are preferably the undersides of the leaves or columns. The colorfully drawn larvae have a similar way of life as the beetles. They feed on aphids or other eggs of the clutch that have already been abandoned. In total, they eat around 400 aphids during their development. They go through four developmental stages up to sexual maturity. The duration of the stages depends on the outside temperature. The larvae do not overwinter, but pupate after a few weeks. The pupae usually hang down from plants and are also colorfully patterned. The total development time is between 30 and 60 days, so that there are usually two generations per year. The life expectancy of the animals is about twelve months.
The seven-point ladybug and man
The seven-point ladybug is considered a beneficial insect , a friendly beetle and a symbol of luck, which is generally applied to the relationship with “ladybugs and humans” . The seven-point ladybirds are considered beneficial insects by gardeners because they eat large numbers of aphids. They are among the first animals to be used in biological pest control .
Others
The seven-point ladybird was declared Insect of the Year in Germany and Austria in 2006 .
media
pairing
when lifting from a plant
Doll
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literature
- Helgard Reichholf-Riehm: Insects. Orbis, Munich 1984, ISBN 3-572-01088-8 .
- Harde, Severa: Der Kosmos Käferführer, The Central European Beetles. Franckh-Kosmos Verlags-GmbH & Co, 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
Individual evidence
- ↑ Peter MJ Brown, Robert Frost, Julian Doberski, Tim Sparks, Richard Harrington, Helen E. Roy: Decline in native ladybirds in response to the arrival of Harmonia axyridis: early evidence from England. Ecological Entomology 36 (2), 2011, pp. 231-240.
- ↑ Helen E. Roy, Tim Adriaens, Nick JB Isaac, Marc Kenis, Thierry Onkelinx, Gilles San Martin, Peter MJ Brown, Louis Hautier, Remy Poland, David B. Roy, Richard Comont, René Eschen, Robert Frost, Renate Zindel, Johan Van Vlaenderen, Oldřich Nedvěd, Hans Peter Ravn, Jean-Claude Grégoire, Jean-Christophe de Biseau, Dirk Maes: Invasive alien predator causes rapid declines of European ladybugs. Diversity and Distributions 18, 2012, pp. 717-725.
- ↑ Sandra Krengel, Gabriele I. Stangl, Corinna Brandsch, Bernd Freier, Tina Klose, Eckard Moll, Andreas Kiowski: A comparative study on effects of normal versus elevated temperatures during preimaginal and young adult period on body weight and fat body content of mature Coccinella septempunctata and Harmonia axyridis (Coleoptera: Coccinellidae). Ecological Entomology 41 (3), 2012, pp. 676-687.
- ↑ Sandra Krengel and Bernd Freier, quoted in Stefanie Hahn: Seven point with home advantage: Which aphid-eating enemy benefits from global warming. Innovation Report, July 16, 2013.
- ↑ Sandra Krengel and Werner Schulze, quoted in Threatened Ladybirds: Comeback with seven points. Der Spiegel, August 16, 2015.
- ↑ E. Wießner: From the world of the beetles Entry: Das Siebenpünktchen , in Illustrirte Zeitung for small people , Volume 7, Schwetschke, Halle, 1878, page 285. ( available online )