Coccinella novemnotata

Herbst, 1793

nine-spotted ladybug, nine-spotted lady beetle, C9

Coccinella novemnotata is a North that experienced a drastic decline beginning in the 1960s. Once among the most common in the northeastern United States and southern Canada, it has become rare across much of its former range. The is a specialized with potential value as a agent in agriculture. It is the state of New York, designated in 1989.

Coccinella septempunctata Fort Worth by Rod Haley. Used under a CC BY-SA 2.0 license.

Field book of insects (6244370848) by Lutz, Frank Eugene. Used under a Public domain license.

Coccinella novemnotata 3097855 by Jesse Rorabaugh. Used under a CC0 license.

Pronunciation

How to pronounce Coccinella novemnotata: //ˌkɒksɪˈnɛlə ˌnoʊvɛmˈnoʊtɑːtə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

The most reliable distinguishing feature from the similar Coccinella septempunctata is the pronotal pattern: C. novemnotata has a complete collar across the entire edge of the , while C. septempunctata has only white corners (lapels) with the remainder black. The extra spot near the shoulder on C. novemnotata can be vague or obsolete, making pronotal characters more consistent for identification. C. novemnotata is typically slightly smaller and more often creamy orange rather than bright red or orange. Must be distinguished from the highly variable Harmonia axyridis, which rarely matches the spot pattern of C. novemnotata. In western North America, Coccinella transversoguttata has spots connected to form a horizontal bar between the shoulders.

Images

Appearance

Small, convex, nearly hemispherical with polished (shiny) texture. Length ranges from 4.7 to 7.0 mm. color ranges from to orange. Each elytron bears four black spots, with a single spot split between the elytra near the shoulder, totaling nine spots. The is black with a complete collar extending from corner to corner across the edge. Males possess a spot on the and a stripe on the .

Habitat

Highly and nomadic, occurring across diverse . Found in agricultural landscapes including cotton, alfalfa, corn, and soybean fields. Occurs in suburban parks and gardens. In natural settings, inhabits open areas with shrubbery and small trees (deciduous or coniferous), meadows, prairie grassland, and riparian zones. Distribution within is driven by , mate availability, and seasonal herbaceous cover for breeding.

Distribution

to North America, historically ranging across the United States and southern Canada from Vancouver Island to Quebec. Now rare across much of former range. Recent collections concentrated in western states (especially with over 40 individuals from western states in 2008), with sporadic records from Midwest and sporadic sightings in Ontario, British Columbia, and Alberta. Last collected from Maryland, Pennsylvania, and Delaware between 1986–1988; last Maine record 1992. Rediscovered in Virginia in 2006 and New York in 2011 after apparent absence. Single 2006 record from Washington, D.C. after 14-year absence.

Seasonality

with two per year in central California. Spring generation aestivate; fall generation adults hibernate. Adults enter through summer and winter, emerging in autumn and early spring respectively. occurs in early spring; in early autumn. Activity and reproduction synchronized with availability in natural vegetation; diapause occurs even when prey abundant in irrigated agriculture.

Diet

Specialized . and feed on aphids. Documented to engage in intraguild , consuming , , and molting individuals of other when aphid scarce. Eggs and vulnerable stages are consumed as alternative nutrient sources.

Host Associations

Perilitus coccinellae - that parasitizes ; first Canadian record from Quebec 1955–1956

Life Cycle

with , four larval , , , and stages. Pupae lack covering; larval skin is shed. Eggs laid in clutches attached to thin branches, leaves, or surrounding material. Optimal temperature for development and survival is 21–27°C (70–80°F). At 32°C (90°F), egg production severely reduced and most eggs infertile, likely due to in males. Two per year with spring and fall adult cohorts.

Behavior

exhibit aggregational , particularly during . Nomadic movement patterns tracking and breeding resources. Diapause is -dependent: short (10–12 hour) and long (18 hour) photoperiods induce diapause in many adults, while intermediate photoperiods (14–16 hours) permit . Low temperature and reduced food availability enhance diapause-inducing effectiveness of extreme photoperiods. Susceptible stage for diapause induction is young adult from to 7 days of age. Documented and intraguild increase during scarcity.

Ecological Role

with potential as agent in agricultural systems. decline has reduced its contribution to natural pest suppression. Coexists with more abundant through subtle partitioning, though at much reduced abundance.

Human Relevance

Designated state of New York in 1989. Subject of extensive citizen science through the Lost Project and Cornell University efforts to document remaining . Valued for potential in agriculture. Listed as endangered under Canada's at Risk Act (2023) and by COSEWIC (2016); ranked as imperiled (N2) in Canada by NatureServe. Not protected under U.S. ; globally ranked G5 (secure) by NatureServe.

Similar Taxa

Coccinella septempunctataNearly identical appearance; distinguished by pronotal pattern ( corners only vs. complete white collar), slightly larger size, and brighter coloration. from Europe and implicated in displacement of C. novemnotata.
Harmonia axyridisHighly variable spot pattern can resemble C. novemnotata; distinguished by greater variability in both elytral spots and pronotal markings, and typically more on region.
Coccinella transversoguttataWestern North with spots connected to form horizontal bar between shoulders; also declined following C. septempunctata establishment.

More Details

Population Decline

Drastic decline began around the 1960s; causes remain unidentified despite extensive research. (Harmonia axyridis, Coccinella septempunctata) and agricultural intensification hypothesized but not strongly correlated with decline patterns. (neonicotinoids, ) have documented negative synergistic effects. Mobile, nature complicates efforts despite high public and scientific interest.

Conservation Status Complexity

NatureServe global rank (G5, secure) conflicts with national and regional assessments due to mismatch: remains present across broad range at very low abundance. Canadian federal endangered status contrasts with lack of U.S. federal protection.