Fireflies & Cucuyos: Twin Glows

The Glowing Cucuyo

Pyrophorus • Bioluminescent Click Beetle

The bright, steady neon beams gliding through our high forest canopy are produced by the extraordinary Cucuyo (the bioluminescent click beetle of the genus Pyrophorus). Unlike true fireflies, these large, sturdy beetles belong to the family Elateridae. They are famous for their twin luminous "lantern" spots on their back (pronotum) which glow like green headlights in the dark, and a third, even brighter organ on their abdomen that illuminates during flight. Known for their energetic snapping "click" mechanism that launches them into the air when disturbed, their steady, non-flashing glow was historically used as natural lanterns in Central America.

The True Firefly Dance

Lampyridae • Bicellonycha & Aspisoma

While the Cucuyo shines with a steady, continuous headlight glow, true fireflies (family Lampyridae) paint our cacao groves with delicate, pulsing flashes. In our tropical valleys and forest clearings, you can spot species like Bicellonycha amoena, which flies low over damp grass and cacao plantings with brief, rapid flashes, alongside the wide, shield-backed fireflies of the genus Aspisoma. On warm, damp nights, entire colonies of Bicellonycha adjust their flash timings to match their neighbors, culminating in a spectacular, wave-synchronized symphony of light.