Explanation of Names
Coccinella trifasciata Linnaeus 1758
trifasciata (L). 'three banded'
Numbers
One species worldwide, with two subspecies in our region:
Coccinella trifasciata perplexa (C. t. trifasciata = perplexa)
Coccinella trifasciata subversa
Identification
From Gordon's key to the species
(1), the following features are seen on these beetles:
1) elytra suture reddish, not black or dark brown (excludes C. novemnotata and C. californica)
2) "head pale except for black band across base (male); or dark and with broad pale band between eyes, band rarely interrupted medially (female)". (excludes those with "head dark with 2 well separated spots on front" - including C. transversoguttata, C. septempunctata, and C. undecimpunctata)
Range
C. trifasciata perplexa- Most of North America north of 40 deg. latitude, except Pacific coast, northern Alaska, northern Canada
C. trifasciata subversa - hugs the west coast, CA to BC
(1) Remarks
considered by New York State to be a "Species of Greatest Conservation Need" (SGCN)
(2)See Also
Transverse Lady Beetle,
Coccinella transversoguttata - Pronotum with black anterior margin.
Some species of Hippodamia have similar markings, but shape is elongated and tapered, not rounded.
Internet References
Systema naturae, 10th ed., v.1, p.365 - Linnaeus' original description of the species (in Latin).