Rare thread-legged assassin bug ‘missing’ for 100 years rediscovered in limestone caves in the Andamans

A rare thread-legged assassin bug described from Siju Cave in Meghalaya a century ago has been rediscovered by scientists from the Andaman Islands, highlighting rich biodiversity of the less-explored subterranean ecosystem of the archipelago.

Two thread-legged assassin bug specimens collected by a team of biologists from limestone caves in the Andaman Islands in 2019 were identified as Myiophanes kempi, a species that had not been reported for the past 100 years after its first description by British entomologist Willian Edward China in 1924.

A paper on the rediscovery and redescription of the species after a century was published in the journal Subterranean Biology recently.

“The species has not been reported in the past 100 years nor illustrated ever before,” said Manchi Shirish S., Principal Scientist with the Conservation Ecology division at the Salim Ali Centre for Ornithology and Natural History (Sacon), Coimbatore, and the corresponding author.

According to the study, finding of Myiophanes kempi in the Andamans is significant because the species was not found during a survey of Siju Cave in the Garo Hills by researchers in 2019. The species has been rediscovered from a similar cave environment over 1,000 km southeast.

The specimens collected from the Andamans were matched with photographs of one syntype female (out of the six specimens collected from Siju Caves in 1922 and described by W.E. China in 1924) that are preserved in the Natural History Museum, London.

Belonging to the subfamily of Reduviidae, this slender-bodied assassin bug is a specialised predator of the subterranean ecosystem and lives in its complete lifecycle in the darkness. It uses the long raptorial forelegs for snatching prey — small arthropods of the dark cave environment.

Dhanusha Kawalkar and Pooja Patil from Sacon, and Hemant V. Ghate from the Department of Zoology, Modern College of Arts, Science and Commerce (Autonomous), Shivaji Nagar, Pune, co-authored the study, funded by the Ministry of Environment, Forest and Climate Change and The Habitats Trust.