ECR Spotlight – Leonardo Turchen Free

Leonardo Turchen

How did you become interested in biology?

I believe that my early connection with nature played a pivotal role in sparking my interest in biology. I grew up in a well-known agricultural region of Brazil (Mato Grosso state), where fields and crops stretch as far as the eye can see. However, this region is also characterized by its stunning natural beauty and remarkable biodiversity, as it is positioned in the transition between two biomes – the Amazon Rainforest and the Cerrado Savanna – and close to a third, the Pantanal Wetlands. It is truly a privilege to call such a place home. Some of my most vivid childhood memories are filled with adventures in nature: fishing, hiking, exploring waterfalls and camping with my parents, during which I would constantly pester them with a lot of questions. I also fondly remember being fascinated by Hercules beetles – staging little ‘battles’ between them – as well as mischievously scaring my younger sister with the loud cicadas that I caught in our backyard. Looking back, I can see how these moments were more than just childhood joys, they instilled in me a deep curiosity about the natural world.

Describe your scientific journey and your current research focus

My scientific journey in entomology began during my Bachelor's degree at the Universidade do Estado de Mato Grosso (Brazil), where I investigated the impact of pesticides on insects (target and non-target) and explored biocontrol methods in both laboratory and field settings. Following this, I pursued an MSc and PhD in entomology at the Universidade Federal de Viçosa (Brazil) under the supervision of Dr Raul Guedes. My research during this period focused on the intersection of behaviour and pest management. A turning point in my career occurred during the transition from my MSc to my PhD, when I discovered the fascinating field of biotremology. This piqued my curiosity and led me to investigate how insects generate and use vibroacoustic signals. During this time, I was awarded a 1-year scholarship for a visiting research position at Carleton University in Ottawa, Canada, under the supervision of Dr Jayne Yack. Although the COVID-19 pandemic disrupted my plans, the experience allowed me to establish a meaningful collaboration with Dr Yack and her research team. Together, we reviewed vibratory sensing and communication in insects, identified critical knowledge gaps and outlined future research directions. We also investigated the role of vibratory signals in mediating interactions between pest caterpillars and their natural predators, as well as the broader influence of vibratory landscapes on caterpillar behaviour. After completing my PhD, I continued in a 1-year postdoctoral position in Dr Guedes's lab. Subsequently, I was invited to a postdoctoral position in Dr Yack's lab at Carleton University, where I am currently engaged in research. My current work focuses on a caterpillar species that initially exhibits group living behaviour but later transitions to a solitary lifestyle. Specifically, I aim to understand how vibratory signals mediate group formation, cohesion and eventual separation. Additionally, I am investigating whether these vibrations play a role in coordinating activities within temporary groups. By addressing these questions, I hope to gain insights into how caterpillars communicate and contribute to broader questions about social interactions among insects.

How would you explain the main findings of your paper to a member of the public?

In our study, we found that recently hatched warty birch caterpillars, no bigger than a grain of rice, claim the tip of a birch leaf as their territory and use vibrations to defend it. When alone, these tiny caterpillars produce vibratory signals to broadcast their presence. But when another caterpillar comes too close, the resident ramps up its signalling – four times more if the intruder is nearby and up to 14 times if the intruder reaches the leaf tip (or territory). Surprisingly, these contests are ‘fought’ entirely with vibrations, not physical aggression. One might call it ‘vibratory diplomacy’. Most often, the original resident wins, holding on to its tiny territory.

What do you enjoy most about research, and why?

I absolutely love every part of the research journey, whether it's diving into a detailed literature review, coming up with new ideas, planning and running experiments, analyzing results, interpreting data, having thought-provoking discussions, writing papers, presenting findings or brainstorming new research projects. Each step brings its own set of challenges and opportunities to learn. Research feels like assembling a puzzle, discovering each piece and understanding how it contributes to the bigger picture. What excites me most about being a researcher is the freedom it offers: the ability to explore topics that ignite curiosity and inspire a better understanding of the world around us. This independence keeps me motivated to expand the boundaries of knowledge.

What is the most important piece of equipment for your research, what does it do and what question did it help you address?

The laser Doppler vibrometer (LDV) is a game-changing tool in my research! What sets the LDV apart is its non-invasive approach, allowing us to study a natural system without causing disruption. For example, one can record from tiny insects interacting on their natural host plants. The LDV works by directing a laser beam onto a surface and detecting minute oscillations in the surface through a phenomenon known as the Doppler shift. These laser oscillations are then converted into electrical signals, providing a highly detailed picture of how vibrations change over time, including their frequency and amplitude. When combined with high-resolution video recordings, the LDV enables us to better understand how insects generate vibrations, analyze the acoustic properties of the signal, and investigate how environmental factors – such as leaf or stem characteristics – affect signal transmission. This technology enables us to explore the vibratory interactions within an insect's environment, revealing how they use vibroacoustic signals to interact with other organisms in their complex community networks. In short, I would say that the LDV is helping us unlock the secrets of the insect vibratory world – one vibration at a time!

What's next for you?

I am finishing my postdoctoral research at the Yack Lab at Carleton University (www.yacklab.org/). However, my collaboration with Dr Yack and our work in insect vibroacoustic is far from complete. We have a wealth of data to process and analyze, which will refine our hypotheses and deepen our understanding of these fascinating communication systems – exciting results are on the horizon. To move forward with our research, I have applied for competitive grants and remain optimistic about securing funding to further push the boundaries of this field. At the same time, I am actively pursuing academic positions and am enthusiastic about the opportunity to establish my own research lab. This next phase would enable me to continue investigating insect vibroacoustics, mentor and train the next generation of scientists, and make meaningful contributions to this vibrant and dynamic area of research.