A melanic (darkly pigmented) form of Harmonia axyridis. Entirely black with a white central head marking, two rounded pronotum markings, and two red or orange elytral markings. Occasional extreme variants may have reduced or absent white markings on the pronotum.
The extended black pigmentation forms a layer over the usual pattern. Thus, sometimes the standard pattern shows through. In these cases, a black spot from the usual form will show over the red marking, creating a crescent or C-shaped spot.
Uncommon, mostly in w. NA, but spreading (BG data).
Hosino, Y. 1940. Genetical studies on the pattern types the lady-bird beetle, Harmonia axyridis Pallas. Journal of Genetics 40: 215–228.
Majerus et. al, "Guide to Ladybirds of the British Isles", Field Studies Council 2006.
Michie, L.J., F. Mallard, M.E.N. Majerus & F.M. Jiggins. 2010. Melanic through nature or nurture: genetic polymorphism and phenotypic plasticity in Harmonia axyridis
. Journal of Evolutionary Biology 23: 1699–1707. (Full Text
Komai, T. 1956. Genetics of lady beetles. Advances in Genetics 8: 155–188.
Komai, T., M. Chino & Y. Hosino. 1950. Contributions to the evolutionary genetics of the lady-beetle, Harmonia .1. Geographic and temporal variations in the relative frequencies of the elytral pattern types and in the frequency of elytral ridge. Genetics 35: 589–601.
Roy, H.E., & P.M.J. Brown. 2015 Ten years of invasion: Harmonia axyridis
(Pallas) (Coleoptera: Coccinellidae) in Britain. Ecological Entomology 40(4): 336-348. (Full Text
Tan, C.C. 1946. Mosaic dominance in the inheritance of color patterns in the lady-bird beetle, Harmonia axyridis. Genetics 31: 195–210.
Tan, C.C. & J.C. Li. 1934. Inheritance of the elytral color patterns of the lady-bird beetle, Harmonia axyridis Pallas. The American Naturalist 68: 252–265.
Ueno, H. 1994. Intraspecific variation of P2 value in a coccinellid beetle, Harmonia axyridis. Journal of Ethology 12: 169–174.
Wang, S., J.P. Michaud, R.Z. Zhang, F. Zhang & S. Liu. 2009. Seasonal cycles of assortative mating and reproductive behaviour in polymorphic populations of Harmonia axyridis in China. Ecological Entomology 34: 483–491.