Geography & BiodiversityImportant2025-07-14

Four New Idris Parasitoid Wasps Discovered

Q: Which of the following statements is/are correct regarding the newly discovered Idris wasp species in West Bengal? 1. They are primary egg parasitoids of jumping spiders. 2. They exhibit solitary parasitism, where only a single wasp develops per spider egg sac.

A. 1 only — Statement 1 is correct as they target jumping spiders (Salticidae). Statement 2 is incorrect because these wasps uniquely exhibit 'gregarious parasitism', where multiple wasps emerge from a single spider egg sac.

In News

What Happened

In July 2025, researchers from the Zoological Survey of India (ZSI) discovered four new species of microscopic parasitoid wasps in West Bengal. Named Idris bianor, Idris furvus, Idris hyllus, and Idris longiscapus, these tiny insects were found in agricultural and semi-natural habitats. They specifically target jumping spiders by laying their eggs inside the spider egg sacs.

Why It Matters

This discovery is vital for understanding natural biocontrol mechanisms within Indian agroecosystems. These wasps exhibit 'gregarious parasitism', making them powerful natural regulators of spider populations and essential for maintaining arthropod community balance.

Background

History & Context

The Zoological Survey of India (ZSI) has been actively documenting micro-fauna to build a genetic reference library for lesser-known insects. Between 2021 and 2023, a research team led by Dr. K. Rajmohana collected specimens across West Bengal. The findings were formally published in the European Journal of Taxonomy in July 2025, utilizing a combination of traditional morphological studies and modern DNA barcoding.

What Changed

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BEFORE: India's genetic database for the Idris genus was highly limited, with few DNA sequences available globally. NOW: The discovery adds crucial molecular data for four new species, significantly expanding the genetic reference library for parasitoid wasps.
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BEFORE: Spider population regulation in Bengal's agroecosystems was not fully mapped at the micro-fauna level. NOW: The identification of these wasps as primary egg parasitoids of jumping spiders provides a clear biological mechanism for natural arthropod population control.
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BEFORE: Parasitoid development strategies in Indian Idris species were under-documented. NOW: The newly discovered species highlight the rare phenomenon of 'gregarious parasitism', where multiple wasps develop simultaneously within a single jumping spider egg sac.

Prelims Angle

NCERT Connection

This discovery strongly correlates with Class 12 Biology Chapter 13 (Organisms and Populations), specifically the concepts of Population Interactions and Parasitism. It serves as a real-world example of 'gregarious parasitism', illustrating how parasitic relationships function as natural population regulators within an ecosystem.

Practice Questions

Q1

Correct Statement(s)

Which of the following statements is/are correct regarding the newly discovered Idris wasp species in West Bengal? 1. They are primary egg parasitoids of jumping spiders. 2. They exhibit solitary parasitism, where only a single wasp develops per spider egg sac.

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