A morning visit to the pumpkin patch
Go outside while your pumpkin or zucchini flowers are still open. Stand beside a blossom and look down into its yellow cup. A bee may be moving deep inside, dusted with pollen. You may also find several bees resting in one flower, as in the photo.
What squash bees do for a garden
A squash plant makes separate male and female flowers. Look behind the petals. A female flower has a small swelling at its base that can grow into a squash. The male flower rests on a slender stem. When a bee moves between the two, it can carry pollen to the female flower.
Female squash bees gather pollen from plants in the genus Cucurbita to feed their young. This group includes pumpkins, summer squash and many gourds. Honey bees and bumblebees also visit the same blooms. Watch a few flowers before deciding which visitors you have. Penn State Extension explains pollination in these crops.
Where squash bees build their nests
The bee you see in a blossom may have a nest in the soil nearby. A female digs a tunnel and makes chambers below ground. In each chamber she leaves a supply of pollen and an egg. The young bee develops there, out of sight.
If you see bees entering one patch of soil near the vines, mark the spot so you can leave it undisturbed. Deep digging or tilling there can destroy nests. You can watch their flight path without opening the tunnel.
Squash Bee Facts
How did growing squash change where these bees live?
Indigenous farmers grew squash beyond the range of its wild relatives. That gave the eastern squash bee, Eucera pruinosa, a source of pollen in new places. Genetic evidence links the spread of cultivated squash to the bee’s expansion across North America. Read the researchers’ study of the range expansion.
Can bees tell cultivated and wild squash flowers apart?
Researchers found signs of selection in genes related to smell in eastern squash bees. They proposed that the scent of cultivated plants helped shape that pattern. The study did not measure changes in the bees’ color vision. Read the genomic study and its findings.
How can I record squash bees in my garden?
Write down the time, the plant and which flower the bee visited. If you have a camera, try for a clear side view. A visit is worth noting even if you cannot identify the species.