The female, shown below, is less showy, but has a better 'dress sense' in my opinion. As their name implies, Scarlet Baskers love to bask in the hot sun. When they do it, during the warmest times of the day, they are often quite approachable for photography (you need a bit of technique, of course).
Scientists assume that wing patterns, body size and colour all help the male dragonflies to recognize the females of their own species. Females of some species may closely resemble females of another species, and if the two species share the same habitat, males may grab any female they can. At times males will even grab other males only to realize their mistake later on. Just like this male found out.
This is hardly surprising as some dragonfly males are almost identical to the females in their looks. Take a look at this post to see how similar the two sexes of the Sri Lanka Forktail are.
As I explained here, to initiate sex, a male dragonfly grabs a female by the head—often in mid-air, using special appendages at the end of their abdomen. This vital part of male anatomy will only fit to perfection with females of the same species. If the fit isn’t quite right, the female will not be impressed and will not cooperate in connecting her genital openings with the male’s copulatory organ, which is at the second segment in case of the dragonflies. When that happens, the male will soon let go to hook up with another—in all good sense of the phrase.
So, although dragonfly sex appears forceful especially with their submissive aerial manoeuvres, the female dragonfly has the final say in “choosing” her mate by this act of non-cooperation.
Most dragonfly males remain focused on mate-guarding at pre-copulatory, and post-copulatory stages, and will chase away any intruders.
You may ask why mate-guard at post-copulatory stages? That is because girls can misbehave. And due to sperm competition. That is intruding males can ‘remove’ sperm packets delivered by the males that have mated previously, which in the case of the intruding male is a way of ensuring that his genes are passed on to the progeny. For this end, dragonfly males are endowed with multi-purpose intromittent penises fashioned with brushes, and hooks that function to physically remove rival sperm from the female reproductive tract.
In some dragonflies, their multi-purpose penises also can provide sensory stimulation during copulation for the females to induce ejection of any previous sperm received before delivering his load. Furthermore, they can also ‘reposition’ the rival sperm to an area in the reproductive tract of the female that is less likely to cause fertilization. Another method is 'sperm flushing' by displacing any previously stored sperm in the female reproductive tract by the new deliveries.
So, doesn’t the female have any choice of “choosing” the sperm she wants just as any self-respecting female would do? The answer is, yes. Just as males have evolved sperm-displacement mechanisms using their fancy gear, females too have presumably evolved means to avoid sperm displacement. For this end, females have sperm storage spaces that allow them to manipulate the sperm they've received—to avoid sperm displacement, re-distributing sperm masses, favouring sperm located in certain sites and ejecting sperm after copulation.
So, as it is the case with most animals, in dragonflies mating first will not ensure that you will farther a child. This explains why some male dragonflies appear to be paranoid with mate-guarding at post-copulatory level, by holding up to the back of the female’s head, and remaining in tandem until the female deposits her eggs.