| does thermal melanism maintain melanic polymorphism in the two-spot ladybird, adalia bipunctata (coleoptera: coccinellidae)? | melanic polymorphism in adalia bipunctata is usually said to result from cyclical seasonal selection acting on the morphs: predominantly black individuals gain a reproductive advantage in the spring and summer, red forms gaining an advantage during the winter. the veracity of this proposition is based largely on a series of samples taken in berlin-buch in the 1930s by timofeeff-ressovsky (1940). these show considerable and reasonably consistent cyclical changes in the frequency of the morphs. we ... | 2000 | 10999004 |