Blue-winged Helicopter Damselfly
Blue-winged Helicopter Damselfly

Blue-winged Helicopter Damselfly

Megaloprepus caerulatus

Photo by Domiciano Alveo

With a wingspan of up to 19 cm, the Blue-winged Helicopter is the largest member of the dragonfly and damselfly order, Odonata. It is large, with a body length up to 13 cm, and slender. In addition to their large size, Blue-winged Helicopter damselflies have dark brown to black bodies with yellowish markings, and transparent wings with a dark blue band on the outer third near the wing tip. Males are distinguished by having a thick white band on the wings inside the blue band. Females lack this white band, but have a creamy white spot at each wing tip. Males are larger than females, which is unusual among dragonflies and damselflies. The Blue-winged Helicopter damsel is the only member of the genus Megaloprepus.

The Blue-winged Helicopter damselfly is a member of the family Pseudostigmatidae, the helicopter damsels and forest giant damsels. They are called helicopter damselflies because their four wings beat independently, and appear to whirl around like the blades of a helicopter. Helicopter damselflies are only found in tropical regions, and require environments with plenty of rainfall – rainforests are their ideal home. This species is the most spectacular of Panama’s 6 species of helicopter damselflies.

Blue-winged Helicopter damselflies are found in the understorey of tropical rainforests. They do not emerge to cross large clearings, and have poor flight endurance, resting often by perching on a leaf or twig with its abdomen hanging downward. They are most common in mature, old-growth forests and are not commonly found in secondary growth. Adult Blue-winged Helicopter damsels specialize in plucking spiders from their webs while in flight using their long legs. They prefer small, soft-bellied spiders that are easier to eat.

Blue-winged Helicopter damsels breed in phytotelmata – small pools of water formed in plants such as bromeliads and in tree cavities. Due to its size, it requires water in tree cavities to lay its eggs and provide the habitat for its larvae, called naiads or nymphs, to develop. The naiads have three featherlike gills, called caudal lamellae, at the tip of their abdomens for breathing. Each of the lamellae of this species have a distinctive white spot, making the naiads easy to identify. They are carnivorous and are the top predators in their unique aquatic habitat – they feed on mosquitos and other flies, tadpoles and even other nymphs!

Males are territorial and defend their breeding pools in tree cavities. They seek out larger bodies of water for several reasons: larger pools can hold more naiads, they can contain more prey for the naiads to eat and therefore the naiads grow faster and attain adulthood sooner, and in the dry season, larger bodies of water will last longer before drying out. Males mate with any female that approaches prior to laying eggs. The eggs hatch in a minimum of 18 days. Adults live up to 7 months, and are present throughout the rainy season.

The Blue-winged Helicopter Damselfly is fairly common around the Canopy Family lodges and is always exciting to find, with its animated, slow, undulating flight and floppy wings.