Variation in the colour of the keel petals in lotus corniculatus l. 3. pollination, herbivory and seed production

Abstract

The response of pollinators to the pseudo-cryptic polymorphism of dark/light keel colour in Lotus corniculatus has been studied experimentally. Some evidence was obtained that the bumble-bees Bombus lapidarius and B. terrestris forage more dark-keeled flowers in dull and overcast conditions than in bright sunlight. The distribution of herbivorous insects within the flowers of L. comiculatus suggests that they do not distinguish between the keel colour phenotypes. The entire seed production of pre-marked plants growing at two sites was recovered. Analysis of the data obtained from one site showed that the phenotypes did not differ significantly in any of the following characteristics: pods produced, seeds produced, seeds per pod, seed herbivores, seed herbivores per pod, damaged seeds, and germination patterns. At the second site no germination trials were effected, but even more closely similar values for seed production and overall seed herbivory of the two keel colour phenotypes were obtained. At the latter site the herbivorous wasp Eurytoma platyptera was commoner in the pods of light-keeled plants and light-keeled plants produced more seeds than the dark-keeled plants later in the season even though light-keeled plants tend to flower earlier. © 1986 The Genetical Society of Great Britain.