Helicopter Damselfly (Megaloprepus coerulatus)
Spanish name: Gallito Azul, Libélula
Moist and wet forests in the lowlands of Costa Rica are the normal grounds for finding this insect. The damselfly is often in the understory, but will also lift up into the canopy, notably if it is startled.
This damselfly and others in its family can live between Mexico and Brazil. Some can live as high as 1,189 m in elevation, but this particular species tends to stay lower. Within Costa Rica it can be found both in the Caribbean and southern Pacific lowland regions. It may also be found slightly higher in elevation in premontane forests in the country.
Tortuguero National Park, Corcovado National Park, Wilson Botanical Garden, Las Cruces Field Station, La Selva Reserve and Biological Station, and La Amistad International Park.
Damselflies are smaller than dragonflies and less robust. There are two other species of helicopter damselflies that live in Costa Rica. Megaloprepus coerulatus is the largest and has bluish purple bands on its otherwise transparent wings. This is a long-bodied damselfly with long wings—the longest wings, in fact, within its order. Each of these long wings moves slowly and independently from the other wings, creating a mesmerizing effect as the damselfly lilts gracefully through the understory.
Biology and Natural History
While the helicopter damselfly is slower than some insects, it maneuvers with finesse. This delicate insect is aggressively predaceous throughout its life. As a nymph developing inside a bromeliad tank, the damselfly will consume other insects and even other nymphs of its own species. It grows to specialize on spiders as an adult, plucking them directly from webs. The damselfly’s mostly clear wings and slim figure are inconspicuous to the spider, and the damselfly can hover nearby without the spider reacting. In a swift move the damselfly rushes the spider, removes the fat abdomen from the web, reverses in flight and perches nearby to eat. It leaves the rest of the body in the web or falling to the ground.
As an adult, this damselfly preys predominately on spiders.
The great wings of this insect can reach 19 cm.
Henderson, Carrol L. Field Guide to the Wildlife of Costa Rica. University of Texas Press, Austin, 2002.
Hogue, Charles L. Latin American Insects and Entomology. University of California Press: Berkely and Los Angeles, 1993.
Stout, J. in Janzen, Daniel H. Costa Rican Natural History. Chicago: University of Chicago Press, 1983.
-Amy Strieter, Wildlife Writer