Common Name
The official common name is the sevenspotted lady beetle; it is sometimes also referred to as C-7.
Scientific Name
Coccinella septempunctata (L.)
The drawing of a sevenspotted lady beetle is borrowed from John Obryicki, Iowa State University. The distribution map is borrowed from Acorn (2007).
Description - Elytra (hardened forewings) are red-orange with 7 black spots, three on each elytron and one forming centrally and anteriorly when the elytra are closed - Pronotum (behind the head but in front of the elytra) is black with 2 pale spots - 6.5 to 7.8 mm in length Note: Other species of lady beetles are very similar in size and colour, making species level identifications tricky at times. For the sevenspotted lady beetle look for a dome-shaped/nicely-rounded body, seven black spots on the elytra and a black pronotum bearing 2 pale spots. Other species of lady beetles within the same genus, Coccinella, share a similar body shape, but will generally have distinctive markings of their own on their elytra (e.g. 9 spots or 3 stripes) and pronotum.
Habitat This lady beetle is found in a wide range of non-forest habitats such as croplands, fields, suburban lawns, dune grasses, and gardens.
Invasion History The sevenspotted lady beetle is native through much of Europe and central Asia. Between 1956 and 1971 it was released across North America as a biological control agent for aphids. In 1973, an established population of the sevenspotted lady beetle was found in New Jersey, but it was not the result of an intentional release. Since then, the sevenspotted lady beetle has become a very common lady beetle across North America.
Regional Sightings The sevenspotted lady beetle has been the most common lady beetle in the Maritime Provinces for approximately the last 20 years. It has been found in Prince Edward Island since 1982, mainland Nova Scotia since 1984, and Cape Breton Island since 1985.
Potential Impacts Introduced species can have huge economic and environmental costs, and can dramatically affect distribution, abundance and reproduction of native species. Recently, ecologists and conservation biologists have voiced serious concerns over negative impacts that introduced species are having on Canada’s ecosystems, placing their threat second to habitat destruction. Since the arrival of the sevenspotted lady beetle there has been a noticeable decline in the abundance of some species of native lady beetles in Manitoba, West Virginia, Midwestern USA, and South Dakota. The sevenspotted lady beetle has also been implicated in the extirpation of the ninespotted lady beetle (Coccinella novemnotata) in Quebec and Ontario. Presently, there are no studies to document specific effects in the Maritimes.
Additional Websites of Interest
- University of Guelph Insect Collection - fact sheets about lady beetles of Ontario
- Discover Life – fact sheet about Coleoptera: Coccinellidae Latrielle 1807
Literature Acorn, J. 2007. Ladybugs of Alberta, finding and connecting the dots. The University of Alberta Press, Edmonton, Alberta Gordon, R.D. 1985. The Coccinellidae (Coleoptera) of America North of Mexico. Journal of New York Entomological Society 95: 1-912. Majka, C.G. and D.B. McCorquodale. 2006. The Coccinellidae (Coleoptera) of the Maritime Provinces of Canada: new records, biogeographic notes, and conservation concerns. Zootaxa 1154: 49-68. McCorquodale, D.B. 1998. Adventive lady beetles (Coleoptera: Coccinellidae) in eastern Nova Scotia, Canada. Entomological News 109(1): 15-20.
