The reason for incomplete growth of fruits and flowers in pumpkin crop

Pumpkin crops are still planted in most of the field.
Some fruits are appearing, but they are not fully developed, and they are small in size.
This problem is due to the poor activity of honey bees because of weather changes.
As you all know, honey bees naturally support pollination in pumpkin crops.
If there is a decrease in the activity of honey bees, then the growth of fruits of the pumpkin fruit is improper or fruit is not produced.