Research Interests

林柏安 Po-An Lin

I am Po-An, an assistant professor at the Department of Entomology of National Taiwan University. I am interested in many aspects of interactions between insect herbivores (especially lepidopterans), their host plants, and their environment. Among the environmental factors, water limitation is one of the most common stresses in all terrestrial ecosystems, limiting plant productivity/survival. A better understanding of how water availability affects plant-insect interactions is a critical step in understanding how abiotic factors influence the dynamics of species interactions and is especially important in understanding how climate change affects ecosystems and agriculture. 

My research investigates how drought stress affects the interactions between plants and insect herbivores. I used a combination of field ecology, chemical ecology, plant physiology, and molecular biology (e.g., CRISPR/Cas9) approaches to study factors that influence the outcomes of drought-plant-insect interactions. My research has led to the discovery that drought stress leads to tradeoffs between defense strategies of plants against insect herbivores and how drought-stressed plants alter species interactions among arthropods. A fascinating finding is the ability of insects to induce drought-like responses (i.e., stomatal closure) to manipulate plant defense responses. These results suggest the general importance of water stress in the evolution and ecology of plant-insect interactions. 

In addition to water availability, our recent work reveals that light is an important driver of plant-herbivore interactions.  We discover that adult diel preferences of Lepidopteran herbivores are tightly connected to their host range. The associations that day-flying moths and butterflies are more specialized in their diet is further linked to the fact that plants emit significantly more volatiles during the day than at night. This hypothesis is named the "Salient Aroma Hypothesis" which argues the importance of the availability of plant chemical cues in the evolution of herbivore host use patterns. We believe this novel hypothesis will serve as an important hypothesis that explains the biodiversity of Lepidopteran herbivores and as the foundation for future studies investigating how plant volatiles influence plant-insect interactions (the manuscript is currently under review).


2015 - 2021          PhD, Department of Entomology; International Agriculture and Development Program, Pennsylvania State University (USA)

2009 - 2015          BS, Department of Entomology; Department of Plant Pathology and Microbiology, National Taiwan University (Taiwan)


2022 - Present     Assistant Professor, Department of Entomology, National Taiwan University

2021 - 2022          Postdoctoral Researcher, Institute of Plant Science, University of Bern

2015 - 2021          Research Assistant, Department of Entomology, Pennsylvania State University

2014 - 2015          Research Assistant, Applied Zoology Division, Taiwan Agricultural Research Institute


Chemical Ecology (Main Instructor)

Practice in Integrated Plant Health Management (Co-instructed)

Plant Disease and Insect Control (Co-instructed)

Teaching Statement

Teaching is one of the reasons why I pursue an academic career. I decided to pursue an academic career studying insects and plants during college because I found them intriguing biologically and indispensable for the survival of human society. However, I realized that there is a general lack of connection to the natural world and a lack of understanding of nature's importance in our society. Recognizing this problem, I made it my long-term goal to engage in activities that increase awareness of the importance of all life forms on earth, especially using plants and insects as a model. I believe being a professor in university is one of the best ways to influence young minds and positively impact our society.

Persuading or conveying an idea to people can be difficult. Therefore, it is important to develop a set of effective communications and teaching skills. To find out the best teaching approach, I have been actively observing my teachers throughout all stages of my education, reflecting how each teaching method influenced me and learning from my own teaching experience. These observations yield two major principles that I believe to be fundamental for successful learning and teaching, which are interest and clarity. Interest motivates students to learn for themselves, whereas clarity gives both teachers and students a clear picture of what they aim to achieve in the class.

Self-motivated students usually perform the best. The motivation is usually based on the student’s interest in the topic. I use two approaches to boost students’ interest. First, I spent class time discussing their preferred topics in the course agenda, based on questions such as, why do you choose this course? Why do they think certain topics are important? These discussions help me connect and understand students’ perspectives. Second, based on this information, I rearranged each topic’s proportion and order accordingly and added adequate activities, such as field trips or experiments. Starting with important topics that fit students’ interests, such as topics that connect to their lives, students are more engaged, leading to better performances.

In addition to inciting interests, it is also crucial for the teacher to know what their goals are in the class and what they expect from the students. From experiences throughout my education, I realize that students often do not immediately see the importance of specific topics, especially topics that are very challenging and not immediately applicable. I used to dislike statistics as an undergraduate student because the instructor was vague about the purpose of each lecture and what he expected us to learn. He focused mainly on making sure all the materials were covered regardless of whether students understood it or not. I later find out during graduate school the essential and exciting part of statistics in biological sciences. Our current understanding of biological phenomena is primarily determined by statistical significance. I ended up taking four different statistics courses, and I am much more competent in statistics after this training. As a student, I didn't always know what was important when learning a new topic. Fortunately, I’ve met teachers who provided clear learning objectives and introduced each new topic's importance in coherent ways that connect old concepts with new ideas. I find these approaches helpful and have adopted them. I strive to be very clear about the goals of the course, each lecture, what I expect the students to learn from each activity, and what the bigger picture is of each activity. Clarity on expectations and goals in class will reduce confusion and provide a tangible path for students. Being clear about the bigger picture orient students toward the most important aspects of each topic without going astray and distracted by details; I want them to see the forest, not just the trees.

People learn in different ways; while the conventional lecture is efficient and essential in delivering knowledge, I think learning through interaction is one of the most effective ways to absorb knowledge. Especially in a discipline like biological sciences primarily built on discoveries via experiments. One of the fascinating parts of biology is the living organisms we studied. I realized over the years that hands-on experience for students to interact with the organisms or biological processes that they are learning in the classroom could incite interest leading to better learning results. And without these experiences, I think no matter how well a student can memorize theories and information from the class, students’ knowledge of biology is likely incomplete without these hands-on experiences. Owing to this, I strive to use methods in addition to lectures to teach, such as lab activity and field trips, to give students first-hand experience and a more comprehensive understanding of what they are learning in class.

I believe in the importance of discussion and conversation in learning. While lectures are essential to efficiently summarize knowledge into concentrated and accessible forms, it is crucial to be aware that knowledge is not constant. Knowledge is challenged and changed over time as we advance our understanding of the natural world. Student needs to recognize this very nature of modern science and to do so, the ability to challenge ideas and critically analyze knowledge is essential. Therefore, I strive to incorporate as much discussion or debate-based activities as possible in my classroom. This activity is crucial in building the ability to think critically and communicate ideas effectively with others, which are two of the most important skills in academia and our lives.

I am a person who strives to be inclusive and empathetic, especially after years of experience studying abroad. From a culturally Chinese family in Taiwan, I never felt out of place growing up because 95% of Taiwanese are Han Chinese. As an undergraduate student, I used to be unaware of the struggles and hurdles faced by students from marginalized groups, such as indigenous or from other countries. However, the years in the United States have transformed me. It was a challenging experience because of cultural differences, language barriers, and being introverted. I experienced many obstacles socially and academically. Going through these difficulties allows me to truly relate to marginalized students' struggles. This experience taught me how to be empathetic and inclusive. To help others with similar challenges, I became a member of the Departmental Diversity Committee, representing the international students in our department and trying to help them transition to new life in the USA. These experiences have made me more sympathetic and compassionate. I believe these experiences have given me the sensitivity to understand difficulties experienced by my students and the willingness and ability to help my students based on their individual needs and challenges.

In conclusion, I have obtained a collection of effective teaching techniques from my education. These experiences have shaped into two main principles: (1) inciting interest (2) providing clarity. I aim to be a teacher that guides my students to their interest/passions and provide a clear picture of what I expect them to learn. Using hands-on and conversation-based approaches, I want my students to have a more comprehensive understanding of the knowledge and learn to critically think and communicate with others. I strive to learn from my students and continuously adjust my teaching approaches to maximize my students’ education and be a better teacher myself.

Diversity, Equity, Inclusion Statement

As an international scholar, the effort to promote diversity, equity, and inclusion are especially important to me and have impacted me positively throughout my career. During the years in the United States, I met people that have unique identities, perspectives, experiences, and characteristics (D, Diversity) and experienced the benefits conferred from a culture that proactively increase access of opportunities for all (E, Equity) and a culture that celebrates, welcomes, and respects different values (I, Inclusion). I also experienced situations where the values of DEI are neglected and how damaging it can be to our professional success and personal life. These experiences have strengthened my belief that engaging in DEI work is of essential for academic success and for creating an overall more happy and healthy space for all.

My efforts in promoting DEI values are apparent in my scholarly works. I have collaborated with 36 researchers across the world from USA, Colombia, Japan, Korea, Nepal, India, Malaysia, and Taiwan. Working with a diverse group of international scholars has improved my communication skill and ability to empathize with others who have different views. It is especially important for ecologists to work with a diverse group of researchers with different backgrounds and perspectives, because ecological phenomena are complex, different opinions is helpful for generating novel ideas that are previously neglected. In addition to intellectual benefits, connections from around the world allow me to expand the scope of my research into different geographic locations which broaden our scientific contributions and make our conclusion robust. Studies that have broad impacts are those that include diverse views and perspectives that is applicable to others. These aspects resonate well with the core values of DEI. Hence, engaging in DEI activities is important for academic success and advancement.

To contribute to building a culture that values DEI, I participated in the formation of Diversity Committee in the Department of Entomology at Penn State, leading to drafting of a departmental Diversity Statement, and several mechanisms that promote DEI, such as weekly events that facilitate socializing within the department; special seminar series that invited speakers with excellent achievements in DEI works. I serve as the representative of international students in the committee and gather opinions and feedbacks to better address issues and challenges that are experienced by international students. The process has helped me understand different hurdles experienced by international scholars and how we can help to change for the better.

In conclusion, the values of DEI are essential in my academic career and is shown by the efforts I have put in engaging activities that promote DEI. I am committed to continue the promotion of DEI values. I strive to better myself by participating in DEI training programs and forming new initiatives that helps promote DEI in the future. I believe creating an environment that is inclusive and diverse is important for personal success and therefore the success of the institute especially in the modern world.