All cultivated pumpkins (Cucurbita pecies) have separate male and female ( = unisexual) flowers, requiring pollinators to transfer pollen for fruit set. Pumpkin flowers provide abundant pollen and nectar resources to attract bees.
This is especially important for the female Peponapis pruinosa (eastern cucurbit bee), as she relies exclusively on cucurbit pollen to provision her offspring.
“Squash bees” (refers to two related genera, Peponapis and Xenoglossa) are pollen specialists ( = oligoleges) on pumpkins and closely related plants due to their specialised foraging habits/adaptations and frequent visitation in cultivated fields.
While Europe lacks these specialized “pumpkin bees”, honeybees, bumblebees, and halictid bees step in to do the job.
- More about squash bees: https://en.wikipedia.org/wiki/Squash_bee
- More about the Peponapis pruinosa: https://en.wikipedia.org/wiki/Peponapis_pruinosa…
- Pfister, S. C., et al. (2017). Sensitivity of commercial pumpkin yield to potential decline among different groups of pollinating bees. Royal Society open science, 4(5), 170102.
