I have several thriving pumpkin vines. No mildew or other disease or
parasite problems. I have one fruit that has formed which you can
practically watch as it grows. I have many female flowers which begin
to form (with the fruit at the base) but before the flower actually
opens, the fruit shrivels up and dies. I have read materials which say
that a lack of pollination is the cause for withered fruit and that
manual pollination would be the work-around. However, does this apply
if the female flowers haven't even opened yet? How does one pollinate a
flower if it isn't ready yet? Also, could there be another issue which
is causing the withering fruit?

Thanks in advance.