There are two known Adalia species: two-spotted and ten-spotted lady beetles. Both are found in Europe. Two-spotted is the only one found in North America.
Adalia bipunctata is the only Adalia species in North America and was once considered the second most common lady beetle. Surveys since the 1980s indicate a population decline for this species, as with several other native lady beetles (Harmon et al 2007 and Cornell University 2013). Stephens and Losey (2003) stated that this species has rarely been collected in recent years.
Declines were first noted during the 1980s. The Lost Ladybug Project (Cornell University 2013) reported A. bipunctata at six sites.
Abundant data are not available, but this species was once considered common and found throughout New York. The population appears to be lower now than in the early to mid-1900s. The decline went largely unnoticed until the 1980s. Reasons for the decline are unknown, but could be because of multiple factors including habitat loss, competition with non-native species, insecticide use, pathogens, and parasites. Most recent observations indicate a range reduction New York. The species has been found in western and northern parts of the state (Cornell University 2013).
Agricultural land has been declining in New York since the 1880s resulting is less suitable habitat for lady beetles. Between 1940 and 1997, there was a 57% decline in farmed land in New York (Harmon et al. 2007). Parasites, parasitoids, pathogens, increased cannibalism, insecticide use, transgenic crops, and hybridization with other species are also considered factors that could reducing two-spotted lady beetle population (Martinez 2006, Cornell University 2013).
Preservation of farmland would maintain or increase suitable open habitat. Pesticide use should be avoided when possible. If pesticide use cannot be avoided: use chemicals that target only the pest, treat only infested area, and select chemicals that do not persist.
Additional research is needed to determine the effects of competition with other coccinellids. Further studies on lab rearing and reintroduction are needed. Additional research is needed to determine specific habitat needs.
This lady beetle can be found in a variety of habitats as long as aphids or other small, soft-bodied insects are present (Street 2001). The Lost Ladybug Project (Cornell University 2013) reported A. bipunctata in gardens, yards/backyards, and woods/trees (non-orchard) in New York.
Historically, this species was found statewide. Currently, the range appears to be restricted to western New York and part of New York City.
A. bipunctata occurs from New England to western United States, including a few Midwest records north to southern portions of Canada. This species is also found in western and central Europe.
Adalia bipunctata is 4-5 mm long and ovoid-shaped. The head and thorax is black with yellow markings. Elytra are orange-red, typically with one black spot on each (Street 2001). However, there are variations that include: four to six spots, transverse markings, or a black background (Marshall 2000). Undersides are black to reddish-brown. Larvae are soft-bodied, black with yellow and white spots, and elongate (Street 2001).
The primary diet is soft-bodied insects, especially aphids. Pollen is also consumed.
The best time to look for lady beetles is early summer when it isn't too dry.
The time of year you would expect to find Two-spotted Lady Beetle present and active in New York.
Two-spotted Lady Beetle
Adalia bipunctata (Linnaeus, 1758)
Cornell University. 2013. “The Lost Ladybug Project.” www.lostladybug.org. (date accessed: December 29, 2013).
Harmon, J.P., E. Stephens, and J. Losey. 2007. The decline of native coccinellids (Coleoptera: Coccinellidae) in the United States and Canada. Journal of Insect Conservation. 11: 85-94.
Marshall, S. 2000. "Lady Beetles of Ontario." http://www.uoguelph.ca/debu/lady/lady-beetles.htm. (Date accessed: January 15, 2014).
Martinez, Danielle. 2006. “Adalia bipunctata, two-spotted lady beetle.” https://instruct1.cit.cornell.edu/courses/icb344/abstracts/Two-spotted-ladybeetle.htm (date accessed: January 16, 2014).
NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer.
New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.
Poole, R. W., and P. Gentili (eds.). 1996. Nomina Insecta Nearctica: a checklist of the insects of North America. Volume 1 (Coleoptera, Strepsiptera). Entomological Information Services, Rockville, MD. Available online: http://www.nearctica.com/nomina/nomina.htm
Stephens, Erin and John Losey. 2003. The decline of C-9- New York State’s insect. The Xerces Society. Wings: Essays on Invertebrate Conservation. Fall 2003 pp. 8-12.
Street, R. 2001. "Adalia bipunctata" (On-line), Animal Diversity Web. http://animaldiversity.ummz.umich.edu/accounts/Adalia_bipunctata/ (Date accessed January 16, 2014)
This guide was authored by: Hollie Y. Shaw
Information for this guide was last updated on: March 30, 2015
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Adalia bipunctata. Available from: https://guides.nynhp.org/two-spotted-lady-beetle/. Accessed November 14, 2019.