
Papilionoid Fabaceae include species with flowers that have obstacles that have to be actively moved by a visitor before floral rewards can be accessed and pollination can take place. Córdoba and Cocucci study six species of Fabaceae and determine the force required to open keels and the strength that pollinating bees (Megachilidae and Apidae) are capable of exerting. They find that almost all bees have more than enough strength to access all flowers with the exception of the relatively weak honey bee Apis melifera. The tripping mechanisms of the flowers therefore do not appear to exert a strong influence in selecting pollinators.