In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species (Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones beha...

Bumblebees (Bombus spp.) and honeybees, Apis mellifera, both use odour cues deposited on flowers by previous visitors to improve their foraging efficiency. Short-lived repellent scents are used to avoid probing flowers that have recently been depleted of nectar and/or pollen, and longer-term attractant scents to indicate particularly rewarding flowers. Previous research has indicated that bumbl...

Many co-sexual plants segregate female and male function among flowers on an inflorescence through dichogamy or the production of unisexual flowers. Sexual segregation may reduce self-pollination among flowers within inflorescences (geitonogamy), thereby increasing the pollen available for export to other plants. To assess these complementary roles we manipulated the simultaneously hermaphrodit...