The Pumpkin and the Bee

pumpkin-300x189When you think of October, you think of pumpkins! We will have pumpkins to carve this month and pumpkins to eat in pie next month.  Pumpkins are so prominent during October and November we hardly give their back-story even a thought.


Cucurbita is Latin for gourd and this is the name given to the genus in the gourd family that includes the pumpkin we know well.  There are many species in this genus, including Curcurbita pepo, the slightly ribbed and deep yellow to orange thick-skinned pumpkin and Cucurbita argyrosperma  (Japanese pumpkin) or Cucurbita moschata (crooked neck butternut squash).   Pumpkins, including all squash are native to North America and are one of the most popular crops in the USA, with Illinois, Indiana, Ohio, California and Pennsylvania being the top pumpkin producing states.


But we could not have all these varieties of pumpkins if we did not have bees.  Pumpkins are usually planted in early July and begin to produce both female and male flowers in a few weeks.  In order to be pollinated and bear fruit, the male, and the female flower have to be visited by a bee.  The squash bee Peponapis pruinosaspecializes in visiting flowers of the cucurbit family: pumpkin, squash, zucchini, etc.  Squash bees emerge in early July.  The fast flying bees begin to forage, working between dawn and mid morning.  These squash bees are quite hairy, allowing a lot of pollen to accumulate on their bodies.  Honeybees, bumble bees, and several types of halictid bees also visit the flowers, but none is as skilled as this specialist bee. The squash bee and cucurbit plants are long-term partners. They have been refining their relationship for millions of years, long before Europeans came to this continent.  About one hive per acre is recommended for sufficient pollination.   However there is trouble in the pumpkin patch!  The delicate balance of ecological relationships has to be kept in mind when applying pesticides.  There has been a reduction of the numbers of squash bees (most likely due to pesticides) and farmers have been known to hand pollinate their crops if the bees are not there to do the job. For an academic explanation of the importance of bees in pollination check out this article from the University of California San Diego: