Coccinella septempunctata, the seven-spot ladybird (or, in North America, seven-spotted ladybug or "C-7"), is the most common ladybird in Europe. Its elytra are of a red colour, but punctuated with three black spots each, with one further spot being spread over the junction of the two, making a total of seven spots, from which the species derives both its common and scientific names (from the Latin septem = "seven" and punctus = "spot").
C. septempunctata has a broad ecological range, generally living where there are aphids for it to eat. and including, amongst other biotopes meadows, fields, Pontic–Caspian steppe, parkland, gardens, Western European broadleaf forests and mixed forests. Both the adults and the larvae are voracious predators of aphids, and because of this, C. septempunctata has been repeatedly introduced to North America as a biological control agent to reduce aphid numbers, and is now established in North America, and has been subsequently designated the official state insect of five different states (Delaware, Massachusetts, New Hampshire, Ohio, and Tennessee) Although C. septempunctata is mainly aphidophagous it also feeds on Thysanoptera, Aleyrodidae, on the larvae of Psyllidae and Cicadellidae, and on eggs and larvae of some beetles and butterflies. There are one or two generations per year. Adults overwinter in ground litter parks, gardens, and forest edges, of treelines, and under the tree bark and rocks.
In the United Kingdom, there are fears that the seven-spot ladybird is being outcompeted for food by the harlequin ladybird. Conversely, in North America, this species has outcompeted many native species, including other Coccinella. Massive swarms of C. punctata took place in the drought summer of 1976 in the UK. It used to be a common sight on the island of Malta, but over the years it has declined in numbers.
Anatomy and physiology
An adult seven-spot ladybird may reach a body length of 7.6–10.0 mm (0.3–0.4 in). Their distinctive spots and attractive colours apparently make them unappealing to predators. The species can secrete a fluid from joints in their legs which gives them a foul taste. A threatened ladybird may both play dead and secrete the unappetising substance to protect itself. The seven-spot ladybird synthesizes the toxic alkaloids, N-oxide coccinelline and its free base precoccinelline; depending on sex and diet, the spot size and coloration can provide some indication of how toxic the individual insect is to potential predators.
Europe, North Africa, Australia, Cyprus, European Russia, the Caucasus, Siberia, the Russian Far East, Belarus, Ukraine, Moldova, the Transcaucasia, Kazakhstan, Middle Asia, Western Asia, Middle East, Afghanistan, Mongolia, China, North and South Korea, Pakistan, Nepal, North India, Japan, Southeast Asia. Also North America (the species was introduced to the United States) and Tropical Africa.
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- Ben Quinn (November 7, 2006). "Home-grown ladybirds put to flight by alien invasion". The Daily Telegraph.
- Parkinson, Justin (5 March 2016). "Could the ladybird plague of 1976 happen again?". BBC News Magazine. Archived from the original on 16 October 2016.
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- J. Blount; H. Rowland; F. Drijfhout; J. Endler; R. Inger; J. Sloggett; G. Hurst; D. Hodgson; M. Speed (2012). "How the ladybird got its spots: effects of resource limitation on the honesty of aposematic signals". Functional Ecology. 26 (2): 1–9. doi:10.1111/j.1365-2435.2012.01961.x.
- N. B. Nikitsky and А. S. Ukrainsky, 2016 The Ladybird Beetles (Coleoptera, Coccinellidae) of Moscow Province ISSN 0013-8738. Entomological Review, 2016, Vol. 96, No. 6, pp. 710–735 ISSN 0013-8738 online pdf