You might not be able to tell, but there are two bumble bees and a honeybee (I think) in that squash blossom.
Later in the evening, I noticed many bees crashing out for the night on the flowers. Maybe the hot weather has made the echinacea especially intoxicating to them.
Notice the poor little guy with his feet up in the air! He was still moving an antenna, so I turned him over. Still, it may have been his last night. He looked like he'd had many a trip through the garden, so maybe this going out in high bee style.
I did look to see if the spider in this link might have been the cause. Unless the spider was off stalking others while this guy faded, I didn't find evidence of the spider at work.