Entomologists have described a new species of the ant genus Paraparatrechina from Yingku village in the East Siang district of Arunachal Pradesh, northeastern India.
Paraparatrechina neela, holotype worker: (A) head in full-face view, (B) body in dorsal view, (C) body in profile view. Image credit: Sahanashree et al., doi: 10.3897/zookeys.1203.114168.
Paraparatrechina is a genus of generally small ants, measuring 1-2 mm long, in the subfamily Formicinae.
They are typically found in the Afrotropical, Australasian, Indomalayan, Oceanian, and Palearctic biogeographic regions.
They are present in various tropical environments, ranging from rainforests to forest clearings, and can be found in a wide spectrum of habitats, ranging from leaf litter on the ground to high up in the canopy.
Currently, the genus encompasses 38 valid species and four valid subspecies.
The Indomalayan biogeographic region has 14 known species, while Paraparatrechina aseta was the only known species in the Indian subcontinent until now.
Worker specimens belonging to the new species of Paraparatrechina were collected from a secondary forest at an elevation of 803 m (2,635 feet) in Yingku village, which is located in East Siang District of Arunachal Pradesh, northeastern India.
“While exploring a tree hole about 3 m (10 feet) up in a steep cattle track in the remote Yinku village one evening, something sparkled in the twilight,” said Dr. Dharma Rajan Priyadarsanan from the Ashoka Trust for Research in Ecology and the Environment and colleagues.
“With the dim light available, two insects were sucked into an aspirator. To our surprise, we later found they were ants.”
“Nestled within a Himalayan biodiversity hotspot, Arunachal Pradesh’s Siang Valley presents a world of unparalleled diversity, much of it yet to be explored,” they said.
“However, this very richness, both cultural and ecological, faces unprecedented threats.”
“Large-scale infrastructure projects like dams, highways, and military installations, along with climate change, are rapidly altering the valley.”
“The impact extends beyond the valley itself, as these mountains play a critical role not only in sustaining their own diverse ecosystems but also in ensuring the well-being of millions of people living downstream.”
Named Paraparatrechina neela, the newly-discovered species is a small ant with a total length of less than 2 mm.
Its body is predominantly metallic blue, except for the antennae, mandibles, and legs.
The head is subtriangular with large eyes, and has a triangular mouthpart (mandible) featuring five teeth.
This species has a distinct metallic blue color that is different from any other species in its genus.
“Blue coloration in animals, except in marine sponges, is a relatively rare phenomenon,” the researchers said.
“However, there are several blue species of vertebrates, like fish, frogs, and birds, as well as invertebrates, such as spiders.”
“While blue coloration is common among many insects, particularly in hymenopterans such as Apoidea, Chrysididae and Ichneumonidae, it is very rare in Formicidae.”
“Blue color in insects is usually produced by the arrangement of biological photonic nanostructures rather than pigments, and it has independently evolved in various groups.”
“This vibrant feature raises intriguing questions. Does it help in communication, camouflage, or other ecological interactions? Delving into the evolution of this conspicuous coloration and its connections to elevation and the biology of Paraparatrechina neela presents an exciting avenue for research.”
The discovery of Paraparatrechina neela is reported in a paper in the journal ZooKeys.
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R. Sahanashree et al. 2024. A remarkable new species of Paraparatrechina Donisthorpe (1947) (Hymenoptera, Formicidae, Formicinae) from the Eastern Himalayas, India. ZooKeys 1203: 159-172; doi: 10.3897/zookeys.1203.114168
