Tamar Keasar

This week's Featured Fellow is Tamar Keasar, a professor in the Department of Biology and the Environment at the University of Haifa, and co-organizer of our Research Group, "Mathematical Modelling of Biological Control Interaction to Support Agriculture and Conservation". We spoke to Tamar about agricultural pests, the benefits of models, and the similarities between humans and bees...

What research are you working on during your time at the IIAS?

My Research Group is working on the topic of biological control, which is the method of controlling agricultural pests through natural predation. This method reduces the use of insecticides, which are unhealthy, costly, and are becoming less effective over time, because the pests are evolving insecticide resistance. The question is how to do biological control in the best way. Previously, people have experimented with different forms of biological control, with some success and some failure, and without using theoretical insights to plan biological control programs.

An alternative method is to look at the basic science of ecology, which describes how populations behave and interact. There are many models that predict what would happen if you were to put two populations, or several populations, together. So our groups is integrating those two methods: to use experimentation alongside ecological models to improve the practice of biological control. Our group is composed of experimental biologists who go out to the field and do biological control in practice, as well as biologists who come more from a theoretical background and have an interest in biological control. So we're trying to get everybody to collaborate and exchange ideas in order to develop improved theories and practices.

Are you focusing on a specific pest species?

We are looking at a broad range of species. We meet with different people here in Israel who are working on specific pests and specific biological control programs, and discuss with them what's bothering them and where they need solutions, so this gives us additional ideas for species to study.

For example, we have a colleague who is an applied biologist working on a specific moth species. The larvae of this moth bore into tomato fruits, and cause a lot of damage. This is a huge issue, because tomatoes are widely grown in Israel and are a big cash crop, so any harm to this crop creates a lot of economic damage. The moth has a natural predator, a predatory bug that is naturally present in those fields, and feeds on the pests. The challenge we were posed was to figure out what population size of predatory bugs is needed in order to sufficiently keep the moth population under control, so that insecticides don't need to be used on the crops. Our group worked together, and made the calculations, and we met with her to discuss our results. This is an example of a specific problem that we can tackle with the help of mathematical modelling.

Do you have a lot of opportunities to visit farms as part of your research?

Yes, we work with real farms and real farmers, and part of the job is learning to talk to them and get their cooperation, because they are really important for these studies. We are trying be useful and to address people's needs. It is also important to talk in a language that they can understand and accept, because sometimes academics use fancy terminology which is unclear to the farmer, so communication is really important.

How did you first get interested in this field?

My PhD was on insect behaviour, and the research didn't have any applied use, it was trying to understand what dictates decision-making in bees as a model for learning about other animals, and maybe even humans. When I did my postdoc, I switched to behaviour, learning and decision-making in parasitic wasps, which are actually natural enemies of agricultural pests. When I started my own lab, new students presented their ideas and their research interests, and I found that many of them were interested in these applied topics, and wanted to make a difference in the world. I adopted their point of view and got into more applied research, which I have really found fascinating. So I learnt from my students.

What's an example of how the behaviour of bees can be reflected in human behaviour?

One finding from my PhD research was how bees allocate their efforts between searching for food in known food sources, and trying out new locations. It's a question of curiosity: would curiosity for something new be a constant in all situations, or would it be situation-dependent? And I found that there is some dependence on the situation. When the bee knows that its environment is very variable and uncertain, then it will be more willing to try new things. And when it is very confident that everything will stay the same, then that tendency decreases. And I think humans work in the same way too, so it's nice to see that it’s a common principle.

How are you enjoying your time at the IIAS so far?

It’s a really lovely opportunity to have time to think, and to write. I really enjoy the interactions with my Research Group, and also with the other Research Groups at the Institute. I don’t normally have many interactions with academics from the Humanities, and so this is really exciting for me. Also, I did my PhD here at The Hebrew University, two buildings away, so it's great to be back on this campus!

Outside of your research, what do you like to do in your spare time?

I like hiking and gardening. Now, in the spring, I spend a lot of time in my garden.

Do you have a favourite hiking trail in Israel?

The Negev highlands and the area of the Ramon crater are very dramatic, and the landscape is different to anything else. It's such an open area, and there are very few people, so it’s the perfect peaceful place to walk, and think, and enjoy the view.

And finally, do you have a book recommendation for us?

Before I came to the IIAS, I spent a few months in London. I read a few books about London, written by people who'd visited London, and one of them is London Observed by Doris Lessing. It’s a collection of short stories, all set in London, and they show different parts of the city and different people in the city, from an outsider's viewpoint. The author immigrated to London in the late 1950s, and she wrote this collection of stories during her first years there when she didn't know the city well. She observed it as a visitor, and so when I came as a visitor to the same city 50 years later, it was very exciting to read her perspective.

 

See also: Featured Fellow