KAYTE YOUNG:  From WFIU in Bloomington Indiana I'm Kayte Young, and this is Earth Eats.

IVETTE PERFECTO:  When the phorids arrive the ants release a pheromone that tells their nest mates, all their sister ants that are in the vicinity, careful, the phorids are here, you better go back to your nest or get paralyzed.

KAYTE YOUNG:  This week on the show we get to nerd out on insects with Ivette Perfecto, who studies Biodiversity and Agro Ecology. She's got some wild stories to tell about bugs on coffee plants, and the importance of understanding the delicate balance between species. Stay with us.

KAYTE YOUNG:  Thanks for listening to Earth Eats, I'm Kayte Young.

KAYTE YOUNG:  My guest today is Ivette Perfecto, she's the Bunyan Bryant Collegiate Professor of Environmental Justice at the School for Environment and Sustainability at University of Michigan, where she leads the Perfecto lab, focused on Biodiversity and Agroecology.

IVETTE PERFECTO:  My lab is an agroecology lab, and what I do in my lab with my students is conduct research primarily in agroecology. In particular, we're interested in understanding the ecology of agricultural systems, so that we can manipulate them and enhance them for higher sustainability, resilience, productivity as well. Most of the work that is done in my lab is related to insects. And so we're interested in biodiversity of insects and arthropods in general, and their role in the agroecosystem.

KAYTE YOUNG:  If it has been a while since you were in a science classroom, here's a little refresher. Arthropod refers to any member of the phylum or group Arthropoda, which is the largest group in the animal kingdom. It includes lobsters, crabs, spiders, mites, insects, centipedes and millipedes. More than 80% of all known species of animals falls into the arthropod category, and you'll find them in every habitat on earth.

IVETTE PERFECTO:  So insects can be detrimental as well as beneficial. We're more interested in the beneficial insects, and their role as biological control or natural control agents in agricultural systems. The idea being that if you can maintain high diversity of natural enemies, predators, parasitoids, and things that eat other insects, that you can then reduce or hopefully eliminate altogether the use of pesticides.

KAYTE YOUNG:  So for our listeners who aren't familiar with the term, could you say a little bit about what Agroecology is?

IVETTE PERFECTO:  Agroecology has been defined as a science, as a practice and a movement. All three. As a science agroecology is what we do in my lab. It's using ecological principles to understand agroecosystems, so we apply ecological theory, ecological principles to the management of agricultural systems. As a practice it's simply using practices that enhance the sustainability of the system. Agroecology relies on biodiversity. Biodiversity is a key component of agroecological practices, and it essentially involves practices that most people are familiar with when they think about organic agriculture. Eliminating pesticides and using biological control.

IVETTE PERFECTO:  Using bioinsecticides and not chemical insecticides. Organic fertilizers. Protecting the soil, protecting the water, reducing the use of water. Recycling materials etc. All these practices we normally associate with organic agriculture. But, it's not just the elimination of pesticides or the substitution of pesticides with biological agents, but it's also the use of the biodiversity. It's the diversification. Finally, as a movement, in agroecology this component is very important because it highlights the social political aspects of agroecology. This is one big difference between agroecology and organic agriculture. When you're talking about organic agriculture you're mainly talking about these practices; nothing to do with the social political aspects.

IVETTE PERFECTO:  But, in agroecology those social political aspects are essential to what agroecology is. Essentially, it incorporates issues of justice for the countryside, for the people that produce the food, and for the consumers as well. So, these reciprocal interactions between people and the environment are very important for the agroecology movement.

KAYTE YOUNG:  So, it's justice for the people who are working in that food system, but also the surrounding communities?

IVETTE PERFECTO:  Exactly. One of the things that is really important in agroecology is the strengthening of the local food system. So, it's not just about producing food, but it's about how food connects all of us, and the strengthening of that food system that includes people that work in the field, farmers and farm workers. People that consume, people that distribute the food. It includes all the stakeholders, all the people that are involved in the food system. The idea is to produce a food system that is a fair system, and that it doesn't contaminate the environment. That it's a sustainable system for future generations.

KAYTE YOUNG:  Well that really is a stark difference between an organic farm which could be using certain sustainable methods for growing food, but maybe is growing food that is being shipped elsewhere, and the local people can't afford it. It's not really strengthening the local food system.

IVETTE PERFECTO:  Exactly. I have visited organic farms in California, everybody that been to Central Valley California have probably passed by organic farms that are hundreds of hectares of a monoculture. And, that would not be agroecological, having so many hectares in just a monoculture goes against the ecological principles involved in agroecology. You can still have organic farms that have unfair labor practices, and again that goes against the principles of agroecology.

KAYTE YOUNG:  You talked about your lab focuses on insects. Can you share an example of how your insect research is applied to the Biodiverse agroecological systems? I would love to hear the story about the ants.

IVETTE PERFECTO:  I love ants. Ants are fascinating organisms. One of our research projects that has been going on for many years is in Mexico, in the highlands. Well in Chiapas Mexico. In the coffee growing region of Chiapas, which is the southern most state of Mexico. In that region we have been working in agroforestry systems of coffee, where coffee is produced under shade. There is a particular ant that we have been studying for a long time, this is the Azteca ant. Azteca is the genus of the ant. It is called Azteca sericeasur, but we just call it Azteca. The Azteca ant is a really effective predator against the coffee berry borer, which is one of the main pests in coffee, and other pests of coffee.

IVETTE PERFECTO:  And this ant is iboriale, that means it nests on the trees. So it forms a nest in cavities that are on the shade trees of the coffee agroforestry system. And sometimes it forms a nest that is similar in appearance to a wasp nest. When the colony gets really big it constructs a carton nest. The Azteca ant is a very effective predator, but the farmers don't like it. First of all it, is very aggressive, it bites the farmers, so when they have to prune the trees the ants crawl over them and bite them. But, also the farmers can see that this ant has a mutual relationship with a scale insect that is a pest of the coffee as well. The green coffee scale.

IVETTE PERFECTO:  So when I say a mutualistic relationship, I mean that they benefit each other. So the ant tends the scales, people are probably familiar with aphids in their gardens. Ants tending aphids, and the same behavior happens with the Azteca ant. They tend the scales, and in exchange for protecting the scale against their natural enemies, the scale releases a sugary solution called honey dew. The ants use that as their main source of energy. The ant acquires the honey dew, and in exchange they protect the scale insects from their natural enemies. The farmers see these and say, "A friend of my enemy is also my enemy", so I want to get rid of this ant. But, what happens is the main natural enemy of these scale insects is a Coccinellidae beetle, like a ladybird beetle.

KAYTE YOUNG:  The ladybird beetle is harassed by the ants. When the ladybird beetle approaches the area where the scale insects are, they get harassed by the ants and scared away. Sometimes they are even killed by the ants. You might think the ants are not good because they're scaring away the natural enemy of the scale insects, which are a pest of coffee. What we discovered is the the coccinellidae beetle has larval stage, and the larval stage of the beetle has waxy filaments all over its body, and is protected against the predatory aggressiveness of the ants. So the larvae can be in plants that are filled with ants, and the ants can't do anything about them.

KAYTE YOUNG:  And, so here you have the ladybird beetle larvae that are hanging out in this area, and they are eating some of the scale insects, but the problem is the ants harass the adult beetles. So, we started questioning what's going on here? You have this larvae that is eating the scale insects, the ants cannot prey on them because they have the waxy filaments that protect them. But the adults are harassed by the ants. So how is it possible that the adults are able to oviposit on these plants, the larvae gets to the plants, if the ants are harassing the adult beetles? So, we discovered the beetles hide their eggs under the scales, and they also look for other places to hide their eggs.

IVETTE PERFECTO:  So, that's an answer to one of our questions, how are these eggs able to survive in the plants that are filled with ants? The ants are very aggressive and they like the eggs, they will bring the eggs back to their nest. Then we thought how are these beetles able to oviposit, take their time to find the scales, oviposit under the scale if the ants are there, and the ants are attacking the adult beetles? That's when we discovered that there is a parasitoid fly that attacked the ants. This is phorid fly. A common parasitoid of hymenopterans, which is the group of insects that ants belong to. The phorid fly parasitoids, when they attack the ants, the ants get paralyzed because the parasitoids need the movement of the ants to be able to oviposit on the ants and attack them.

IVETTE PERFECTO:  And, so when the phorids get to the plants the ants get completely paralyzed, or they hide, or go away. So, you have this period of time when the phorids arrive where the ants are paralyzed and their activity is hugely reduced, and that provides a window of opportunity for the beetles to go to the plant and oviposit, and hide their eggs under the scales. This is incredible because what you have here is an insect that is basically using this opportunity provided by the parasitoid that is attacking the ants. What was more incredible that we discovered later is that essentially the adult female beetle that needs to oviposit on the plant, actually can sense the pheromones of the ants when the phorids arrive.

IVETTE PERFECTO:  Because when the phorids arrive, the ants release a pheromone that tells all the other ants that are in the vicinity, "Careful the phorids are here, go back to the next or get paralyzed". So, the ant activity decreases, and the beetle can sense that signal that the ants are giving to their nest mates, and use that as a signal to say this is a safe time to come to the plant, and the ants are not going to harass you or kill you. We have done experiments with olfactometers, a device where you put different odors and pheromones, and look at the behavior of the beetle.

IVETTE PERFECTO:  We have demonstrated that essentially the female beetles are able to detect the alarm pheromone that the ants release when the phorids arrive. It is a particular pheromone that is released when the phorids arrive because we tested these with the regular alarm pheromone, and they don't react to that. They get attracted to the specific pheromone that the ants release when the phorids arrive. Essentially, they have been able to decipher the communication between the ants, and use that as an opportunity to oviposit.

KAYTE YOUNG:  So you're saying that it's not just a general alarm signal that the ants might give off. It is specific to this species. "Hey we're about to get paralyzed, either get paralyzed or back into the nest". And it's also interesting to hear that they have that system so it's not just that every single ant is getting attacked. It's that the ants are retreating, and the ones that don't retreat are paralyzed, so that allows that window.

IVETTE PERFECTO:  Yes they get catatonic, they stop moving because the phorid fly needs the movement to be able to attack the ants. It's a very specific pheromone that they release to give that signal, because the other alarm pheromones cause general activity and aggressivity of the ants. When they release an alarm pheromone, that's a general pheromone that makes them more aggressive, more active. It gives a very different reaction in the ants to what they release when the phorids arrive.

KAYTE YOUNG:  Also this story involves four different insect species all around the coffee plant, and the tree that's shading the coffee.

IVETTE PERFECTO:  Yes. The incredible thing is that coffee is not a native plant to the Americas. Coffee was introduced to the Americas maybe 200 years ago. This whole complex system which is very fined tuned with the female beetle responding to this particular pheromone that the ants release when the phorids arrive. This system must have evolved in the Americas, the other species are native to the Americas. The ant, the beetle, the phorid flies are native. The scale insect on pan-tropic, so it occurs all throughout the tropics. My hypothesis is that this system had evolved in the natural system, but once coffee was introduced it basically moves into this coffee system.

KAYTE YOUNG:  Ivette Perfecto tells this story beautifully, but it's a lot to take in in one listen, especially without any visuals. Let me summarize again just to make sure you understand the fantastic complexity of this system. Coffee berry borers are a pest that destroys coffee beans. Azteca ants attack and control these borers, so they're good for coffee plants. However, they also tend or farm green coffee scale insects, which are not good for the coffee plants. The ants protect the scale and the scale release a sugary liquid that the ants consume for energy. Along comes the ladybird beetle who in its larval stage eats the scale.

KAYTE YOUNG:  So that's good for the coffee plant. The ants defend the scale by harassing and attacking the adult ladybird beetles. But the ants cannot attack them in their larval stage because they're covered in a waxy filament that the ants get tangled up in. So they avoid the larvae. The ants would take the ladybird beetle eggs if they could find them, but the ladybird beetle hides them underneath the scale insects, which are largely stationary. How do the ladybird beetles manage to lay the eggs when the ants will attack the adult ladybird beetles, if they come close to the coffee plants. The beetles wait for a pheromonal signal from the ants. The pheromonal signal is released when a parasitoid called a phorid fly, is approaching. The ants will go and hide or stop moving when the phorid fly approaches to avoid detection.

KAYTE YOUNG:  This is the perfect window for the ladybird beetle to lay their eggs underneath the scale insect. Incredible right? I said it was four insects, but lets count again. One, the coffee berry borer. Two, the Azteca ant. Three, the green coffee scale insect. Four, the ladybird beetle. And five, the phorid fly. That's five. I think there might be a total of eight insects involved in this system. This is just what she had time to tell us about here.

KAYTE YOUNG:  It's time to take a quick break, and when we return Ivette Perfecto, Professor at the School for Environment and Sustainability at University of Michigan, will talk about how this research helps coffee farmers with pest control. Stay with us.

KAYTE YOUNG:  Kayte Young here, this is Earth Eats, and we're back with Ivette Perfecto with the School for Environment and Sustainability at University of Michigan. Hopefully between Ivette's description and my quick summary, this complex relationship between inter-dependent insects is clear. The research is interesting in itself, but this knowledge has real world applications for coffee farmers. Here's Ivette Perfecto.

IVETTE PERFECTO:  As I mentioned before, the farmers don't like the ant because they think that the ant is helping the scale insect, and also the ants are biting them. But the issue is when the ants are there with the larvae of the coccinellidae beetle, because they scaring away all the natural enemies of the scale insect which they're protecting, the scale insect. They also scare about the parasitoids of the beetle larvae. So they're inadvertently also protecting the larvae of the coccinellidae beetle. When you sample this insect throughout the farm, you can hardly find any larvae of coccinellidae beetles outside the clusters where the ants are located. Because they are constantly parasitized by five different parasitoids. A parasitic wasp that attacks the beetle larvae.

IVETTE PERFECTO:  And so that means that the beetle cannot reproduce outside of these clusters of ants. What initially seemed to be a problem for the farmer, where the ants are tending the scale insect, it turned out to be actually the main refuge for the production of the main natural enemy of the scale insects. If they eliminate the ants, they are basically eliminating these clusters where the beetle is reproducing, and is protected from their natural enemies. And this would eliminate the main control of the scale insects, and might general an outbreak of the scale insects.

KAYTE YOUNG:  So are they seeing in the coffee fields that the areas where the ants are nesting, near those trees, that's where there maybe a little bit of a concentration of scale because the ants are tending? But that's also the place where this beetle is reproducing.

IVETTE PERFECTO:  Exactly.

KAYTE YOUNG:  And that beetle is controlling the scale throughout the coffee field. Is that correct?

IVETTE PERFECTO:  Exactly. So, basically what we're telling the farmers is that they need to tolerate a few scale insects in these clusters where the ants are, in order to maintain the main biological control agent of the scale insect in the entire farm. And I should mention that we have a large plot where we have quantified how many trees have nests of these ants, and it's about maybe 5% of the trees on the shaded coffee farm have this ant. Basically, you have a very small area when you consider the entire coffee growing region, very small areas where the scale insects might be at higher densities. The scale insects are in the two or three coffee bushes that are surrounding the trees where the ant is nesting.

IVETTE PERFECTO:  And so out of a thousands and thousands of coffee plants, you have a few plants located right next to where the nest of the ants are, that have hidden cities of the scale insects. But other than that you have also the maintenance of the main natural enemy that control the scales over all the entire coffee farm.

KAYTE YOUNG:  I imagine that it can be difficult to communicate this kind of information to farmers, or to share the complexity of the understanding that you're gaining through this research. How do you work with the farmers to get them to understand the complexity of the system you're observing?

IVETTE PERFECTO:  That's an excellent question. When we started uncovering this whole network of complex interactions, we asked the same question. How can we communicate this to the farmers? Some farmers have a great intuition about things in nature, especially small scale farmers that are there everyday and are observing. Some of these interactions are really hard to observe, or impossible to observe, because they are very indirect interactions. The phorid fly is really tiny and very difficult to see, you need to know what to look for in order to see it. Some farmers are very keen on the complex interactions, but others it's more difficult for them to understand all these complex interactions.

IVETTE PERFECTO:  So, what we decided to do, initially we were just giving presentations, presenting this network of interactions, pictures of the organisms, and what happens. That's fine, but you hear it, and you understand it, and you say "Oh, that's interesting." Then time passes, and then you forget about it, or you cannot explain it to somebody else. So, we decided to develop a board game, that's called Azteca Chess, it basically includes all these organisms. The ant, the scale insects, the beetle larvae and adult beetle, and the phorid fly. Essentially, there are two players, one plays the ant and the parasitoids of the beetle, the other player plays the beetle and both the larvae and the adult.

IVETTE PERFECTO:  The strategy is if you are the beetle, you win the game if you are able to eat all the scale insects that are on the board before you get killed, so if you're able to eat all the scale insects you win. If you are playing the ant, then basically you win the game when you get rid of all the beetles on the board. So it doesn't portray the whole biological control that I talk about before, but it does give the farmers a really good idea of what these interactions are, and all the complexities of the interactions because they have to pay attention if they're at the end. They have to pay attention to where the phorid fly is located, if it's near them they have to move. If you're playing the beetle you have to pay attention to the parasitoids of the beetle larvae, and you have to pay attention to where the scale insects are located, and where the ants are.

IVETTE PERFECTO:  So, you go away from the ants if you're the adult, but close to the ants, if you're the larvae. In the beginning it's a little bit difficult for the farmers, well for anyone. I play it with my students as well. At the beginning it seemed very complicated, but you play it once, and you start getting a good idea of what the strategies are. Eventually you really get into the rules of the game and the strategies.

KAYTE YOUNG:  The roles of each insect. You begin to understand at an intimate level.

IVETTE PERFECTO:  And we actually have done evaluations of how this impacts the farmer's ability to retain the information. We have given presentations to the farmers about the system, and we have had farmers play the game and compare what happens. Those that play the game are able to retain and understand more deeply the interactions, than the one that just receive the power-point presentation.

KAYTE YOUNG:  I mean it makes sense to me that they would retain the knowledge because they're engaged in play. They're in conversation, they're with each other, and they're trying to think like an ant, or think like the parasitic wasp.

IVETTE PERFECTO:  And we have done Azteca chess tournaments with coffee farmers in Mexico. The farmers really get in to it. Initially we have them play both, so that they can get a better understanding of the strategies, whether you're the beetle or the ant, or the parasitoid. So they get a better understanding when they play both roles. Eventually they developing strategies to win the game. So we have these tournaments where they play each other and they keep eliminating each other and, you know, at the end you end up with two people that have won all the games and have been come experts in Azteca chess.

KAYTE YOUNG:  That actually does sound like a fun game. I've played other games like that where you have a role and these are the outlines of what your character, your player can do. So I could see it being a pretty fun game.

IVETTE PERFECTO:  It is fun. I play it every year with my students in my class. And they have a lot of fun.

KAYTE YOUNG:  I'm speaking with Ivette Perfecto about her research on insect interactions in shade grown coffee operations, and how she communicates what she has learned with the coffee farmers. It's time for another short break and then we'll learn more about her background and what brought her to this work. And her fears and hopes for the future of agriculture. Stay with us.

KAYTE YOUNG:  Thanks for listening to Earth Eats. I'm Kayte Young, and my guest today is Ivette Perfecto, Professor at the University of Michigan School for Environment and Sustainability. She leads the Perfecto Lab studying sustainable agriculture practices, agroecology in particular, and she has a focus on insects. Studying their interactions and interdependencies in a search for pest management methods that are integrated with the complex systems of the natural world. I wanted to hear about her background and what brought her to this kind of work.

IVETTE PERFECTO:  I am from Puerto Rico originally, a colony of the United States. When I was growing up in Puerto Rico there was a shift in the economy from mostly agricultural economy, to an industrial economy. There was a push out of the countryside incentivising agriculture in favor of people working in industry. Because of the increase in industry, in particular pharmaceutical companies and petrochemical companies, they were contaminating a lot. Contamination in Puerto Rico increased dramatically. When I went to college to study biology, I got interested in environmental studies. Basically I studied biology, but I got interested in the environmental impacts of these industries in Puerto Rico, and especially the contamination of the oceans and the sea.

IVETTE PERFECTO:  A lot of the contaminants ended up in the rivers, and then eventually in the ocean. I was fascinated by the marine life, I wanted to study Marine Biology initially. I was influenced by Jacques Cousteau's television programs, and living on a Caribbean island I was fascinated by the sea and sea life. I was going to study Marine Biology. But, I also wanted to go out of Puerto Rico to experience something different, so I decided to study in the United States. I applied to several universities and the one that gave me funding was the University of Michigan.

IVETTE PERFECTO:  Now of course the University of Michigan has no sea, it has a lot of lakes, the Great Lakes.

KAYTE YOUNG:  So, she started studying Limnology, the study of inland waters, such as lakes and rivers.

IVETTE PERFECTO:  But at the time there was a group at the University of Michigan called Science for the People. I was also political, I wanted my science to be relevant, to be able to do something good for the people. This group peaked my interest and I started working with them. But in particular there was a subgroup of Science for the People who were basically ecologists who were developing their ecological studies in agricultural systems to understand it better, and develop more sustainable agricultural systems. This is at a time when the word agroecology, didn't exist.

IVETTE PERFECTO:  Nobody talked about organic agriculture. It was radical at the time and this particular group of people were doing studies on inter cropping, diversification of the agricultural system. Planting more than one crop together, and lets study the ecology of this system in terms of pest control, what happens to the soil.

KAYTE YOUNG:  The group led by John Vandermeer was conducting their studies at the Matthaei Botanical Gardens at the University of Michigan.

IVETTE PERFECTO:  They way they were conducting the studies was more like a collective. It was a collective of students that were working together, helping each other. After they finished their work, collecting the data, I volunteered to work with them during the summer. I didn't have any research experience then. I didn't know much ecology, but I learned a lot being out in the field with them. And then after we finished the work we went out, had beer and continued talking about the research and the politics. And, that for me was fascinating.

KAYTE YOUNG:  This experience really opened her mind to how science can be used to benefit people.

IVETTE PERFECTO:  And how much fun it is to be outside and sharing your ideas with other people. And so that hooked me in and I decided to continue to a PhD in something along those lines. Eventually I recognized it was agroecology, but that was my initial inroad to this area of agroecology.

KAYTE YOUNG:  That is a great story. When you look at the loss of biodiversity, I wonder does it hit you particular hard because of your intimate understanding of the complexity of the interactions of even just the few species that you've studied? That you get that if this is happening here, it's happening in all these other places. Many of us who don't do this kind of research, we might not really care about a parasitic wasp. Because of your understanding of the role the species play in an ecosystem, do you feel like it, I don't know?

IVETTE PERFECTO:  Definitely. I think it really breaks my heart what I see the reports over the past decade of the reduction in insect biomass, and insect diversity throughout the world. The main culprit of that is the industrial agricultural system. For example, there's a study that came out a few years ago from Germany where they have been sampling insects for 30 years. They have discovered essentially that insect biomass has dropped by 75%, the sampling takes place in the forest reserves, not even in the agricultural areas. In the forest reserves that are surrounded by agricultural areas, by intensive agriculture,

IVETTE PERFECTO:  and this is only one of many stories that are demonstrating agriculture is reducing significantly insect biomass and insect diversity. So when you see the reports it really makes you cry, because you know all that is being lost when you're losing 75% of the biomass of insects. It's just incredible. If we don't do something we might lose essential components of agricultural systems, one of them being the pollinators. A lot of our crops are pollinated by bees and other insects, if we lose those pollinators it's going to affect agricultural production in a very significant way. I think that people have to be aware of the role of insects, the beneficial role of insects.

IVETTE PERFECTO:  Many insects are also the composers, they play critical roles in the composition. For nutrient cycling they're essential. For pollination they're essential. For biological control they're essential. All these are important functions in agricultural systems, and we're losing them.

KAYTE YOUNG:  What concerns you most right now about our global industrial food system?

IVETTE PERFECTO:  There's so many concerns related to the industrial food system, one of the main ones of course is climate change. People don't recognize that the industrial food system, not just agriculture, the production of food, but the entire food system basically contributes about a third of the greenhouse gases. So, fixing agriculture can contribute significantly to the reduction of greenhouse gas emissions. That is really a crisis, it's not something that's coming up, it's something that is upon us right now at this very moment. I think it is really one of the existential crisis of our time, and we need to do something right away. It's frustrating because you don't see any action, you don't see any action from the politicians and the people that have the power to do something.

IVETTE PERFECTO:  You see a lot of initiatives at the grass root level, which is what gives me hope. Another thing that I think is a crisis in the food system is the injustices of the food system, it's affecting so many people. It's causing a lot of health issues especially among people of color, among poor people that suffer the consequences. Just the pure injustices of a food system that generates so much wealth for so few people.

KAYTE YOUNG:  Do you see small scale farming and agroecology as one of the solutions to some of the problems in our global food system?

IVETTE PERFECTO:  Yes definitely, I think it's probably the main solution. Not the only one but it's the main solution. Large scale industrial agriculture is failing us in so many ways. It's not even producing the food because the food that is being produced in these industrial systems, if you look at it globally, very little of that is being used to feed people. A lot of it is to feed animal, then a few people eat those animals. Some of it is for industrial purposes, like soy bean plantations and oil palm plantations that are taking up millions of hectares of land throughout the world. They're not being used to feed people. Who is feeding people are small scale farmers primarily across the world.

IVETTE PERFECTO:  These farmers are more and more embracing agroecological systems because it makes sense for them. It's not necessarily that it's more profitable, but agroecological systems basically are systems that will provide farmers with a stronger resource base, so they're building their soils. They're building biodiversity, they're building their biological control agents et cetera, and are becoming less dependent on external input and corporations that are reaping all the benefits in the agricultural systems. Agroecology is being embraced by millions of farmers throughout the world. Maybe they don't call it agroecology, it goes by many different names in different places.

IVETTE PERFECTO:  Essentially these systems that are based on biodiversity and ecological principles, recycling and conservation of water and soil. These systems are being embraced by millions of farmers throughout the world,they are the ones that are producing the food that is feeding most people in the world.

KAYTE YOUNG:  You're in Puerto Rico right now and doing field research?

IVETTE PERFECTO:  Yes. I'm working with ants here as well.

KAYTE YOUNG:  Is it in coffee or some other crop?

IVETTE PERFECTO:  We have a project in coffee here. But here we work with ants, but also with vertebrae predators. Here the main vertabrae predators are lizards and cokey frogs. The cokey frogs are really tiny small frogs that are abundant. They are endemic to Puerto Rico, and they're very abundant throughout the archipelago, and they are insectivores. The lizards are also extremely abundant throughout the Caribbean, and they're also insectivores. So we're looking at the role they're playing in controlling some of the coffee pests. But also how they're interacting with each other. Sometimes they actually have negative effect on each other.

IVETTE PERFECTO:  For example, the ants that are very effective predators of certain pests in coffee can also scare away the lizards, or bite them, and the lizards don't like to hangout in plants that have lots of ants. There is this kind of negative interaction between some of the predators, and we're looking at those dynamics of interactions among the natural enemies. What is the net outcome of that? Is it positive or is it negative? And what can we do to try and enhance the more positive affects and reduce the negative effects?

KAYTE YOUNG:  That's interesting. Do you like being out there doing that kind of observation?

IVETTE PERFECTO:  Oh yeah. I love being out in the field all the time.

KAYTE YOUNG:  I really appreciate you taking time out of your day to talk to me. This information is so fascinating and I love hearing about it.

IVETTE PERFECTO:  Thank you very much for inviting me.

KAYTE YOUNG:  That was Ivette Perfecto, Professor at the University of Michigan School for Environment and Sustainability, where she leads the Perfecto Lab, focused on biodiversity and agroecology. You can find links to her work on our website. eartheats.org

KAYTE YOUNG:  That's it for the show this week. Thanks as always for listening and we'll see you next time. The Earth Eats team includes Eoban Binder, Alexis Carvahall, Alex Chambers, Toby Foster, Daniella Richardson, Samantha Schemenaur, Payton Whaley and Harvest Public Media. Special thanks this week to Ivette Perfecto, and to James Farmer and Julie Debrooker-Valliant for connecting us. Earth Eats is produced and edited by me Kayte Young. Our theme music is composed by Aaron Toby, and performed by Aaron and Matt Toby. Additional music on the show comes to us from Universal Production Music. Our executive producer is Eric Bolstridge.