Dazzling New Blue Ant Species Unearthed in India

Researchers in India have identified a new species of blue ant, Paraparatrechina neela, contributing to the unique biodiversity of the Eastern Himalayas and raising questions about its ecological significance. Credit: Sahanashree R, Edited

A team of entomologists has discovered a rare blue ant, named Paraparatrechina neela, in Arunachal Pradesh, India. The find, part of the Siang Valley biodiversity resurveys, highlights the unique fauna of the Eastern Himalayas and sparks interest in its ecological roles and evolutionary traits.

A stunning blue ant has been discovered in Yingku village in Arunachal Pradesh, northeastern India that is nothing like the common red, black, or brown ants. This new species belongs to the rare genus Paraparatrechina and has been named Paraparatrechina neela. The word “neela” signifies the color blue in most Indian languages — a fitting tribute to the ant’s unique coloration.

Collaborative Research Efforts

Entomologists Dr. Priyadarsanan Dharma Rajan and Sahanashree R, from Ashoka Trust for Research in Ecology and the Environment (ATREE) in Bengaluru, along with Aswaj Punnath from the University of Florida, collaborated to describe the remarkable new species. Their scientific description of the ant is published in the open-access journal ZooKeys.

“While exploring a tree hole about 10 feet up in a steep cattle track in the remote Yinku village one evening, something sparkled in the twilight. With the dim light available, two insects were sucked into an aspirator. To our surprise, we later found they were ants” said the researchers.

Paraparatrechina neela. Credit: Sahanashree R

Historical Context of Biodiversity Surveys

The ant was found during an expedition to Siang valley in Arunachal Pradesh to resurvey its biodiversity after the century-old ‘Abhor expedition’. The original Abor expedition from the period of colonial rule in India was a punitive military expedition against the indigenous people there in 1911-1912. A scientific team also accompanied the military expedition, to document the natural history and geography of the Siang Valley.

Тhis expedition encountered several challenges, including hostile terrain, difficult weather conditions, and resistance from local tribes. Despite the challenges, it managed to explore and map large parts of the Siang Valley region, cataloging every plant, frog, lizard, fish, bird & mammal, and insect they found, with the discoveries published in several volumes from 1912 to 1922 in the Records of the Indian Museum.

Contemporary Resurveys in Siang Valley

Now, a century later, a team of researchers from ATREE and a documentation team from Felis Creations Bangalore have embarked on a series of expeditions under the banner “Siang Expedition,” to resurvey and document the biodiver­sity of the region. This expedition was funded by the National Geographic Society through the wild­life-conservation expedition grant.

A view of Siang Valley. Credit: Ranjith AP

Environmental and Ecological Concerns

“Nestled within a Himalayan biodiversity hotspot, Arunachal Pradesh’s Siang Valley presents a world of unparalleled diversity, much of it yet to be explored. 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,” said Priyadarsanan Dharma Rajan, corresponding author of the paper.

Paraparatrechina neela. Credit: Sahanashree R

Physical Characteristics and Rarity of Blue Coloration

Paraparatrechina neela is a small ant with a total length of less than 2mm. 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 colour that is different from any other species in its genus.

Blue is relatively rare in the animal kingdom. Various groups of vertebrates, including fish, frogs, and birds, as well as invertebrates such as spiders, flies, and wasps, showcase blue coloration. In insects, it is often produced by the arrangement of biological photonic nanostructures, which create structural colors rather than being caused by pigments. While blue coloration is commonly observed in some insects like butterflies, beetles, bees, and wasps, it is relatively rare in ants. Out of the 16,724 known species and subspecies of ants worldwide, only a few exhibit blue coloration or iridescence.

Significance of the Discovery

The discovery of Paraparatrechina neela contributes to the richness of ant diversity and represents the unique biodiversity of the Eastern Himalayas, and its blue coloration 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.

Reference: “A remarkable new species of Paraparatrechina Donisthorpe (1947) (Hymenoptera, Formicidae, Formicinae) from the Eastern Himalayas, India” by Ramakrishnaiah Sahanashree, Aswaj Punnath and Dharma Rajan Priyadarsanan, 30 May 2024, ZooKeys.
DOI: 10.3897/zookeys.1203.114168