Scarlet Skimmer Dragonfly

It’s no secret that Florida has all kinds of nasty invaders, from the Burmese phythons trying to eat the Everglades whole to old world climbing fern, which is trying to smoother whole forests.

The scarlet skimmer dragonfly, Crocothemis servilia, is another invader, but a mild-mannered one. In contrast to many non-native organisms that have made their way here, it actually might be a net positive.

These blood-red dragonflies are natives of East Asia, including southern Japan, China and Indonesia, and northern Australia. We’re tempted to use a cute, trite stereotype over the last location, like a dragonfly saying g’day or asking if he could slip another shrimp on the barbie for you, but we refuse to go there. Back to our normal programming.

It’s only the males that are blood-red. Actually only mature males. Females and immature males are a kind of drab yellow and brown mix, somewhat similar to Needham’s skimmer, but they do share a few physical characteristics with mature males.

All scarlet skimmers have orange-veining near the base of their wings (best seen on the photo of the female at the bottom right) and a pale stripe on the thorax. Other similar looking dragonflies don’t have those features.

The dull coloration is actually something of an advantage for young male dragonflies; older males, who might otherwise view them as competitors invading their territory ignore them instead. The change to the deep red signals to females — and competitors — that a young male is ready to step out and sew a few wild oats.

By the way, males transform into the brilliant red of the adult through a process involving a change in body chemistry called nuptial coloration. Our science lesson for the day.

As we said scarlet skimmers are mild-mannered as invaders go. Like all dragonflies, they take to watery habitats, places near and around ponds, lakes, marshes, quiet streams, ditches and canals. But they tend to take to wetlands that are somewhat degraded, places that native dragonflies eschew, so they don't necessarily compete with them for resources.

Like dragonflies generally, male scarlet skimmers are territorial, picking out a nice patch of water with plenty of aquatic weeds where young scarlet skimmers can hide and hunt. They'll defend their turf by darting out at invaders they deem to be competition.

And like other dragonflies, mosquitos, both adults and larvae, are on the scarlet skimmer’s menu both as nymphs or naiads and as adults. That makes them a net positive for us humans, although the mosquito population might disagree.

Scarlet skimmers are perching dragonflies. They like to find vegetation low to the water, where they’ll sit and wait for a nice tasty treat to fly by and ambush.

How they got here is a bit of a guess. There are two theories, one involving the plant trade and one the aquarium trade. The two actually could be the same theory, since the plants could be part of the aquarium trade.

In any case, the presence of scarlet skimmers was first noted in 1975 near Miami. Subsequently, they were then found in Cuba, Jamaica, Puerto Rico and Hispaniola, the island divided between Haiti and the Dominican Republic. It’s possible that the dragonflies arrived in the islands first before hitting the mainland.

The only other state where scarlet skimmers are found is Hawaii. Individuals have been spotted as far north as Tennesee and Ohio, likely hitchhikers on plant shipments. But in no case has a wild population been established farther north than the Florida-Georgia line.

In fact, Central Florida is about as far north as scarlet skimmers are normally found.

Other common names include ruddy marsh skimmer and crimson darter. Scarlet skimmers are members of Libellulidae, the skimmer dragonfly family.

Green Cay Nature Center