The Helicopter Damselfly from Costa Rica
The Helicopter Damselfly is not necessarily such a lady. These bad boys and gals can take down some pretty mean looking web building spiders for a snack.
Distribution
Helicopter Damselflies in the species Megaloprepus caerulatus are found in wet tropical forests of Central and South America. In Costa Rica, it is found in the swamps and mangrove forests of places like Tortuguero National Park, Terraba Sierpe National Wetlands, Corcovado National Park or La Amistad National Park.
Mating & Reproduction
Male Helicopter Damselflies will take possession (in theory) of a tree hole. Most tree holes contain somewhere between less than a liter of water to 50 liters of water. The males will usually pick a tree hole that has a larger amount of water to insure the success of multiple offspring, and then protect it from other males by chasing them away or hitting them. Females will enter the tree hole to lay unfertilized eggs, but the male will copulate with them before he allows them to lay eggs thus fertilizing them.
Once the eggs hatch, they become naiads, and in their tree hole they are the apex predator. Many tree holes will be filled with tadpoles or mosquito larvae which the nymph Helicopter Damselflies will feast on. They also exhibit cannibalism at this point in their lifecycle, and will feast on eggs and other damselflies in the tree hole including of their own species.
The surviving naiads undergo instars (stages of development), and in time morph into adult damselflies. Before that point, they are aquatic animals with a set of gills.
Behavior
Helicopter Damselflies are both aggressive and territorial. They protect their tree holes for reproduction, and they fight for survival from their earliest stages of development. It’s no wonder that they are also excellent and specialized hunters. When seeking food Helicopter Damselflies may fly up and down tree trunks until they find a web building spider. When they find a web building spider, they only attack as long as the light is just right.
If they can see their approach well, they will fly to the web. At the web, they will fly backwards and then forwards snatching their prey by its legs. They then carry their prey back to their tree hole where they tear off the spiders legs before eating its body.
Miscellaneous Info
Some species of damselfly in the family pseudostigmatidae have been dated to the time of the supercontinent Gondwana which was the southern supercontinent of what is now known as Africa and South America. They also have the longest wingspan of damselfly and dragonfly species.
Locations in Costa Rica: Tortuguero National Park, La Amistad International Park, Terraba Sierpe National Wetlands, Corcovado National Park
Diet: web building spiders, trapped insects
Migration Pattern: non-migratory
Habitat: wet tropical forests
Size: length=19 cm (wingspan) Weight=negligible
Species: Megaloprepus caerulatus