There is little specific information available on the biology of the slim scarlet-darter but its life history and behaviour are likely to be similar to those of other dragonflies and damselflies.
Adult dragonflies typically hold a small territory, which is vigorously defended during breeding. Aggression can be increased when there is an imbalance between the numbers of each sex (6). During mating, the male dragonfly holds the female by the head with a pair of claspers on the end of the abdomen. The male may make an attempt to remove any sperm stored by the female from previous mates, and will often try to guard the female from other males during egg laying, to ensure that the eggs are fertilised by his sperm (6).
A dragonfly generally lays its eggs near or in water, and the eggs hatch into aquatic larvae, known as nymphs. Dragonfly nymphs go through several moults before the final moult into the adult form. When the nymph is ready to emerge as an adult, it finds a safe spot hidden from potential predators, as it is very vulnerable at this stage. Once the adult has emerged, it pumps fluid into the veins in the wings to expand them ready for flight. The larval stage of a dragonfly may last for many months, whereas the adult may only live for a matter of weeks (6).
Both adult and larval dragonflies are opportunistic predators, feeding on a variety of prey.