Members of the family Cucurbitaceae have some of the largest pollen grains known. These spiny spheres are designed to stick to insects…squash flowers of all sorts are entomophilous and require insects to move their pollen from male to female flowers. But most bees that visit squash flowers don’t seem to like the pollen very much. I have watched honeybees and bumblebees land on nearby leaves to clean the pollen off instead of into the baskets on their legs as they normally would on a pollen foraging trip. They seem to only visit squash flowers for the nectar.
That’s why the squash bee, Peponapis pruinosa, is so interesting! The squash bee collects only pollen from members of the plant family Cucurbitaceae. Why does it specialize on this pollen that is so unwanted by the other bees? A great question. 😉