The nine-spotted ladybug, commonly referred to as C-9, (Coccinella novemnotata
), is a relatively large (5-7 mm long) ladybug native to North America. Up until 1970, C-9 was the most common ladybug species in the northeastern United States, with a wide range including most of the states and southern Canada. This species had an important natural role in agricultural bio-control due to its wide diet of crop pests (including many scale insects and aphids) as well as its tolerance for living on a breadth of different host plants. However population numbers of C-9 have precipitously declined since the 1970’s for reasons unknown. One hypotheses for its reduced numbers is the introduction and establishment of several other ladybug species (the seven spotted ladybug Coccinella septempunctata
, the Asian ladybug Harmonia axyridis
, the 14-spot ladybug Propylaea quatuordecimpunctata
and the variegated ladybeetle Hippodamia variegata
). These ladybugs invaded the nine-spotted ladybug's range in the timeframe of C-9’s demise, but more data is needed to determine whether they did, in fact, catastrophically impact C. novemnotata
populations, and if so, by what mechanism.
In 1980 C-9 was nominated as state insect of New York, and finally designated with this honor, despite the fact that by the time the paperwork was approved in 1989, this insect's population numbers had dropped, and it has for decades been considered locally extinct in this state. However, a recent discovery of Coccinella novemnotata
on July 30, 2011 on Long Island, (the first New York sighting since 1982), has confirmed that this species is present in small numbers. “The Lost Ladybug Project”, a citizen science group based at Cornell University
, and other conservation groups have started to actively document and research C. novemnotata
and other rare and declining American ladybug species.
; Harmon et al 2007; The Lost Ladybug Project 2011
; Stephens and Losey 2003
; Stephens 2006