From Wasps to Termites: Tracing the Fascinating World of Social Insects with Dr. Ruchira Sen
- Indian Entomologist
- 1 hour ago
- 7 min read
By Rahul Kumar
Insect societies have always intrigued humankind. Even the Vedas, the oldest religious and philosophical texts in the world, contain observations of social insects, especially of honeybees, ants and termites. In 1973, Karl von Frisch was awarded the Nobel Prize for discovering the language of honeybees. The renowned work of the legendary E.O. Wilson on the sociobiology of ants gained global fame and even earned him the title “Darwin of the 21st Century.” Many scientists have systematically studied the behaviour of various social insects worldwide. Prof. Raghavendra Gadagkar from the Centre for Ecological Sciences at the Indian Institute of Science (IISc), Bengaluru, pioneered this area with his studies on the evolution and behaviour of Ropalidia marginata, the Indian Paper Wasp. Dr. Rahul interviewed Prof. Gadagkar, and the interview was published in Indian Entomologist, which can be read using the following link:
In continuation of this venture, Dr. Rahul got an opportunity to interview a college teacher who has worked extensively on the behaviour of social insects ranging from wasps to termites. He met Dr. Ruchira Sen from the PG Department of Zoology, Sri Guru Gobind Singh College, Chandigarh, at the Animal Taxonomy Summit 2026 organized by the Zoological Survey of India, Kolkata. In hymenopteran social insect studies, males have been traditionally ignored as “mere genetic delivery packages” or lazy drones. Dr. Sen's PhD work directly contested this. She showed that males of the primitively eusocial wasp Ropalidia marginata can feed the larvae when females are experimentally removed from the nest. Dr. Sen's recent research has investigated the nesting cycles of Polistes wattii, and their dynamics with a strepsipteran parasite. In addition to wasps, her collaborative research also explores how ants and termites defend their fungus farms. Her recent work on termites was published in “Science” and made headlines across the scientific world. This simple yet elegant and impactful work inspired Dr. Rahul to talk to Dr. Sen regarding her academic journey and research. Here is an account of this fascinating discussion.
Dr. Rahul: Could you please tell us a little bit about your education and your research focus in the early days of your research career?
Dr. Sen: I completed B.Sc. and M.Sc. from Calcutta University, Kolkata. For Ph.D., I joined Prof. Raghavendra Gadagkar’s lab at the Centre for Ecological Sciences, IISc, Bengaluru. During my Ph.D., I studied the behaviour of Ropalidia marginata males. We showed that male wasps can feed larvae voluntarily in the absence of female workers. We challenged the already established notion that the males cannot play any significant role in a wasp colony other than reproduction. We also showed that in captivity, male R. marginata wasps can mate multiple times but females mate only once. After completing my Ph.D., I joined Prof Ulrich Mueller’s lab at the University of Texas, Austin, TX, USA, for my post-doctoral research where I worked on fungus-growing ants followed by another post-doctoral work on termites at Prof Mike Scharf’s lab at Purdue University, Indiana, USA. My present research work is significantly influenced by my previous research experiences.
Dr. Rahul: What inspired you to work on the behaviour of social insects? Is there any specific inspiration or support system you would like to acknowledge?
Dr. Sen: During my B.Sc. and M.Sc., I wasn’t much inclined towards insects. It was my Ph.D. work at IISc, Bengaluru that made me realize the beauty of social insects. So, even though my journey started with the social wasps, I continued to work on other social insects. In India, very few people are working on the behaviour of different social insects. This field is full of possibilities, like a hidden “gold mine” yet to be explored. Since I work in a college, where the main focus is on teaching, my research depends on collaboration for lab work. I am fortunate that my husband, Dr Rhitoban Raychoudhury also works on insects and we collaborate on most projects. So he and his students have been my greatest support system.
Dr. Rahul: Congratulations for your recent publication in Science! Please tell us something about this work.
Dr. Sen: Thank you! This publication is, actually, an outcome of my collaborative research work with Dr. Rhitoban Raychoudhury from Indian Institute of Science Education and Research (IISER), Mohali. I worked on fungus-farming ants at UT Austin and we both worked on functional genomics of lower termites at Purdue. We have been working on fungus-growing termites in India for almost a decade now. The recently published paper in Science is the outcome of many years of experience and efforts by our students and us. Most importantly, it is the result of Dr. Aanchal Panchal’s meticulous and hard work for her PhD and Dr. Renuka Agarwal and Dr. Anjali Rana’s help. We investigated how the fungus-farming termite Odontotermes obesus protects its underground fungal gardens of the basidiomycete fungus Termitomyces from the invasive 'weedy' fungus Pseudoxylaria. We showed that according to the degree of infection, termites respond variably, changing their behaviour to detect, isolate and suppress “weed” fungi with soil boluses mixed with beneficial fungistatic bacteria, while keeping the “crop” fungus unharmed. The results show a sophisticated natural weed control system and offer unique insights into insect farming and symbiotic relations.
Dr. Rahul: Can you tell me about the many kinds of insect systems that you have worked with so far?
Dr. Sen: As I already told you, the first social insect system I worked on was Ropalidia marginata society. I also worked on Ropalidia cyathiformis during my PhD. Then, I worked on many species of fungus-growing ants like Atta texana, Acromyrmex versicolor, Trachymyrmex septentrionalis, Cyphomyrmex muelleri, Mycocepurus smithii, etc. Then I worked on the subterranean termite Reticulitermes flavipes. Now, I mainly work on the paper wasps Polistes wattii and Polistes indicus. However, I also collaborate with Dr. Raychoudhury and his students to work on the fungus-growing termite Odontotermes obesus and the non-social parasitoid wasp Nasonia. We have used various techniques of behavioural, microbial and molecular ecology to answer specific questions on them. When I came to Chandigarh, I started observing and working on Polistes wattii. It was my first independent work after my Ph.D. and post-doctoral training. This work started in 2014 and it took eight years to publish our first paper in 2022. In this span of time, we studied the nesting behaviour of these wasps and found that unlike the temperate Polistes species, which make nests once in a year, Polistes wattii builds nest twice a year: once in spring by solitary wasps and then in summer by multiple wasps. We think the reason for this is the occurrence of long summer season in India vis-à-vis short American/European summer. Long summer means short hibernation period and long period of activity ensuring more individuals in the colony. However, P. wattii is found in many other countries in Asia and we do not know how they behave elsewhere. We are working on the north Indian population of P. wattii and trying to study various aspects of their biology. We discovered a new species of strepsipteran endoparasite Xenos gadagkari that parasitises Polistes wattii. My student Deepak Nain is studying how this parasite affects the behaviour, physiology and microbiota of their hosts. Although a large part of our work is done in the field, without the lab support from Dr. Raychoudhury, this work would not be possible. I am also thankful to ANRF for funding this research. For more information about my research you can refer my homepage, https://www.ruchirasen.in.
Dr. Rahul: What is your advice for the young researchers or those who aspire to become one?
Dr. Sen: Despite comprising the most abundant, diverse, and species-rich animal group on Earth, with over one million described species worldwide, insects remain understudied in terms of behaviour, with only a handful of researchers in India focusing on insect behaviour. My suggestion to young researchers is to go to the fields and start observing insects, you will definitely find something new. One has to start at some point. First, study the system through patient observations and then ask questions that are relevant to that insect. Tenacity and hard work are essential in studying insects, and the rewards are extraordinary! Moreover, the good news is that AI can’t go to the field and observe the minute details like us, at least not at present. So, observing how insects behave and decoding what they mean are still a job meant for humans. This is a field where your individuality is not taken away from you and it can be done even when you do not have a lot of research funds. And once you prove that your work is valuable, many Govt agencies in India can fund your research. Here, you choose your methods and models. Once you start doing it, you will see how you can find answers by asking the right questions.
About the author:
Dr. Rahul Kumar is one of the associate editors of “Indian Entomologist.” He is currently working as an Assistant Professor (Senior Scale) and Head of the Department of Zoology at Sheodeni Sao College (Magadh University), Kaler-824127, India. His ongoing research primarily addresses the behavioural, evolutionary, and taxonomic aspects of insects and spiders. Additionally, he has worked on molecular biology (eukaryotic gene regulation) at JNU, New Delhi; nanotechnology (nanotherapeutics and nanodiagnostics) at AIIMS, New Delhi; science education (activity-based teaching-learning) at NCERT, New Delhi and insect taxonomy (micro-moths) at ICAR-IARI, New Delhi as a research fellow.
Email: rahuldayanand33@gmail.com
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