Caconemobius fori, the Kīlauea lava cricket or dark lava cricket (Hawaiian: 'ūhini nēnē pele,), is a species of lava cricket endemic to the island of Hawai'i. It is found on recently solidified lava flows produced by Kīlauea and Mauna Loa.[1]
Caconemobius fori is a small cricket, approximately in length.[2] It lacks wings but is capable of jumping significant distances when disturbed. This species is darkly colored with an overall shiny quality, causing them to blend in extremely well with the freshly solidified lava that makes up their habitat. They have been noted to look very similar to the volcanic glass ejecta Pele's tears which occur in their habitat.
Caconemobius fori is endemic to recently cooled (on the order of decades) lava flows on the big island of Hawai'i. It is one of the first species to colonize a lava field after its formation, arriving even before any significant plant life can take hold. It is unknown where the crickets occur once a lava field has been colonized by plant life.[3]
Once enough time has passed for any significant plant life to colonize a lava flow, C. fori disappears from the habitat. This species has never been recorded as occurring within 15m of any established vegetation. In contrast, it has been found as close as 100m from an active volcanic vent.[4]
Caconemobius fori is a strictly nocturnal species.
As C. fori is one of the first arrivals after a lava flow is formed, the species relies entirely on windblown debris for food, including plant material and sea foam. Nearly constant winds over fresh lava fields can carry debris multiple kilometers from its source, providing a source of nutrition for these crickets.
While C. fori can be found at night on lava fields without any equipment, it is apparently especially attracted to cheese, which is used by researchers to bait pitfall traps in order to study this species.