Written by Anisha Ghosh
In a major discovery, researchers from the Zoological Survey of India (ZSI) have found four new species of tiny parasitic wasps in West Bengal. These extremely small microscopic wasps belong to the genus Idris Förster and are known for laying their eggs inside spider egg sacs.
Despite their size, they play an important role in nature by controlling spider populations.
The wasps are named Idris bianor, Idris furvus, Idris hyllus, and Idris longiscapus. All four species were found between 2021 and 2023 in the farming areas of West Bengal by a team of scientists led by K Rajmohana at ZSI Kolkata.
“Each new species discovery adds a critical piece to the puzzle of life’s diversity. Understanding these hidden members of ecosystems can reveal essential insights into ecological processes, evolution, and biodiversity patterns,” Rajmohana said.
In an interesting behaviour pattern, the scientists noted that instead of just one wasp growing inside each spider egg sac, many baby wasps grow together and are called “gregarious parasitism”.
Other team members included Sushama V., Inspire Fellow of the Department of Science and Technology (DST), Rupam Debnath from the University of Calcutta, and K P Dinesh from ZSI Pune. Their identification was achieved through a meticulous combination of detailed morphological examination and cutting-edge DNA barcoding. The finding was recently published in the European Journal of Taxonomy.
“An integrated taxonomic approach, which combines traditional morphological studies with modern molecular analysis, is crucial for species delimitation,” explained Dinesh, who provided the molecular expertise for the study.
“Despite their minute size, parasitoids are powerful natural regulators,” said Sushama V, lead author.
Parasitoid wasps like Idris are important because they help control spider numbers and keep ecosystems in balance. This work also adds important DNA data to international science databases, helping scientists all over the world by expanding their knowledge of insect diversity, but also highlighting the remarkable variety of parasitoid wasps.
(Anisha Ghosh is an intern with The Indian Express)