By the scruff of the neck

Mating in dragonflies is unique. The male first transfers sperm from near the tip of his abdomen to accessory genitalia under the front. He then grasps a female by the 'scruff of her neck' with the anal appendages (or 'claspers') at the tip of his abdomen: the pair is then said to be 'in tandem'. If the mood takes her, the female curls the tip of her abdomen to meet the male's accessory genitalia and sperm is transferred; this position is known as 'the wheel', or technically in copula. In some species, such as the chasers, the whole mating process takes only a few seconds; at the other extreme, Blue-tailed Damselflies take up to six hours.
Having said all that, here we have two male banded damsels trying to mate with each other. It would appear that dragonfly testosterone is powerful stuff!