What you have seen sounds a lot like the pheromone release posture noted for Acanthops falcata, which almost always does this only at dawn.
Males of that species only fly at the point as well, and seek out females between the time when bats and birds are out hunting them.
During my fieldwork on Tenodera I noticed that in the late afternoon on hazy days a lot of female Tenodera very fat with eggs would climb high onto goldenrod stems and assume this position with their dorsal abdomen exposed to the air. Usually on those days in the evening you would then see a lof of mated pairs. I'd have to get out my notebook but I'm pretty sure that a great majority of matings happen in the wild (for Tenodera) right around the same time, when all the females are 'calling.'
It sounds to me like your ghost is doing the same thing. See if you can take some pictures, and take note of between which segments (in terms of number) those patches of different tissue you see are located.