Luminary Oddities · Natural history & art
Blue-winged Helicopter Damselfly
Megaloprepus caerulatus
Odonata / Coenagrionidae
Megaloprepus caerulatus is a tropical American damselfly with a long abdomen and broad wings marked in blue and white. Its aquatic larvae develop in water-filled tree holes, where predation and cannibalism shape survival.
Read the species accountAt a glance
- Male marking ↘
- A milky-white band lies immediately inside the blue wing band. [2]
- Larval nursery ↘
- Water-filled tree holes. [3]
Identity and classification
Morphology and identification
Adult males have a dark thorax with yellow stripes and a yellow underside; the long, dark abdomen has a metallic brown-to-blue sheen. The largely transparent wings carry a blue band near the tip. Mature males also have a milky-white band just inside the blue and a narrow white tip margin. Females lack the inner white band and have conspicuous white wing tips. [2]
Distribution and habitat
The species occurs on the Caribbean side of Nicaragua and Costa Rica, in Panama and northern Colombia, and west of the Andes from Colombia to Peru. It inhabits tropical forest. [2]
Life cycle
At Barro Colorado Island, females insert eggs into moist bark above the waterline of tree holes. The aquatic larvae hatch at different times, even within a single clutch. [3]
Feeding and host plants
In the island’s tree-hole nurseries, mosquito larvae are common prey, although larger aquatic prey are preferred. Larger damselfly larvae also consume smaller members of their own species. [3]
Behaviour
At Barro Colorado Island, males defend large water-filled holes that provide mating and egg-laying sites. Females visit these nurseries to mate and deposit eggs. [3]
Distinctive biology
In an experiment, a two-hour decrease in temperature caused more fully developed eggs to hatch than did the ambient-temperature control. In an outdoor insectary at Barro Colorado Island, hatching coincided with cooler conditions associated with rain. [3]
Nomenclature and history
Drury described the species as Libellula caerulata in 1782. The 2022 revision recognized four species of Megaloprepus, separating caerulatus from latipennis, brevistigma and diaboli. [2]
Display and care
Keep the enclosure closed and display it in indirect light, away from heat and damp conditions. Handle the frame by its edges and clean only its exterior according to the maker’s instructions.
Sources and further reading
- Redefining the damselfly families: a comprehensive molecular phylogeny of Zygoptera (Odonata) ↗
Dijkstra, Kalkman, Dow, Stokvis and van Tol; Systematic Entomology 39, 68–96 (2014) · Accessed 2026-10-11
- The damselfly genus Megaloprepus (Odonata: Pseudostigmatidae): revalidation and delimitation of species-level taxa, including the description of one new species ↗
Feindt and Hadrys; Zootaxa 5115(4), 487–510 (2022) · Accessed 2026-10-11
- Novel hatching cue in the neotropical damselfly Megaloprepus caerulatus: larval adaptation and maternal constraint ↗
Arjèn E. van’t Hof and Ola M. Fincke; International Journal of Odonatology 26, 153–163 (2023) · Accessed 2026-10-11
Sources checked 2026-10-11. Illustrations · Luminary Oddities.
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