Dear etaoin: You just flunked entomology 101. But the subject of male fly genitalia reminds me of the seventh grade. The son of the proprietor of the Chinese laundry taught us an amusing prank. He could catch a fly with a
sweep of the hand, open his hand cautiously, and from
the color of the eyes tell the males from the females.
If he had a male fly, he would change his hold carefully,
until the posterior tip of the abdomen was in view, with a
little yellow protuberance, the male sex organ. Using his
fingernail as tweezers, he would pluck the end off this, and
attach a two inch long narrow triangle of cigarette paper to
the sticky goo exposed, and release the fly, which would zoom off trailing the cigarette paper behind it. The teacher was very nearsighted, and would see the paper when the fly lit on the window, and try to pick it up. The fly would zoom away, leaving the teacher with a comically bewildered look on her face.
But finally she found a dead one,and got a good look at it.
After that just a sweep of the hand could get you detention.