Dimorphism of wings, wing-folding and wing-toiletry devices in the ladybird, Rhyzobius litura (F.) (Coleoptera: Coccinellidae), with a discussion of inter-population variation in this and other wing-dimorphic beetle species

Dimorphism of tergal wing-folding spicule patches and wing-toiletry fringes accompanies wing dimorphism in the ladybird, Rhyzobius litura. Such dimorphism of ‘ancillary’ structures is of rare occurrence in the Coleoptera; other instances are discussed. Data are presented concerning the incidence of long and short winged individuals of R. litura in samples from six populations in southern England. Factors likely to influence the relative proportions of the morphs in small populations, and in samples of different kinds, are discussed. Evidence that inter-population variation in the incidence of macropterous individuals has a ‘geographical’ component in R. litura is inconclusive.