How did the honeybee and clovers...?

Question

How did the honeybee and clovers evolve together to form their relationship?

Answer 1

Flowers show a typical insect pollination syndrome to attract a specific pollinator. A flower shape, a distinct colouring and fragrance as well as when the flower is open and the type of reward it offers are all important variables.

Bee flowers typically have a delicate, sweet scent, which the bees can smell. Bees have short tongues so they like composite flowers like clover. They are attracted to open bowl shaped flowers like roses or broad tubular flowers like snapdragons or foxgloves. They see yellow or blue and UV. Because they are pollen feeders the pollen often has its own distinct scent, and is on prominent yellow stamens.

http://www.jstor.org/pss/2446264

Bees are also attracted to flowers shaped to provide warmth.

http://www.pubmedcentral.nih.gov/article...

Social bees will bring other colony members if they find a flowers in a concentrated area.

Clover species (Trifolium spp) vary in their breeding system, some inbreed and some outcross.  Plants that outcross,like globe clover, use pollen as a reward to their pollinators. Bee species (Apis spp) are pollen feeders so are attracted to pollen bearing flowers with a shape that allows them to land easily and offers a sugar rich nectar.

http://www.regional.org.au/au/asa/2001/6...

White clover (Trifolium repens) can have honeybees (Apis mellifera) comprise more than 80% of its insect visitors.

http://www.publish.csiro.au/paper/EA9941...

Trifolium repens nectar has a concentration of 37- 44% as do most bee pollinated plants and the flowers grow in dense clusters to attract the foraging social bees.

apples (Pyrus malus) 28-45%

alfalfa (Medicago sativa) 15-29%

http://www.scielo.br/scielo.php?pid=S010...

http://www.actahort.org/members/showpdf?...