|Male Libellula fulva with partially developed blue pruinosity|
|Pair of Libellula fulva in cop.|
You can tell a male who has mated because the female's front legs, grasping the males abdomen during copulation, leave a "mating scar" - a dark patch where the blue pruinosity has been scuffed up.
|Mature male L. fulva showing "mating scars"|
|L. quadrimaculata male|