With the ever-changing agricultural landscape, researchers continue to push to find ways to produce high-quality and high-yielding crops in a sustainable manner.

Deborah Finke’s research focus is in the same area – on behind-the-scenes helpers that many individuals oftentimes mistake for a nuisance. Finke, an associate professor in the Division of Plant Sciences, is an insect ecologist, meaning she studies insects and their interactions among other organisms, as well as their interactions with their environment. Finke looks at the changes happening in communities and the environment in an effort to understand how those communities and the environment affect insect interactions. The goal is to find ways to better manage agricultural systems with insects in mind.

Finke primarily works with predator insects – insects that prey on smaller, more harmful pests and insects. Predator insects are extremely important in the agricultural world, as they can control pest populations that attack crops.

As an associate professor, Finke has studied a number of predatory insects. She has had several of … Expand ▸As an associate professor, Finke has studied a number of predatory insects. She has had several of her students work with similar insects as well. Students have researched grasshoppers and pollinators among others. Photo courtesy of Deborah Finke.

“If we lose predators or predatory diversity, because they’re so vulnerable to the things we do to the environment, agricultural systems can be affected,” Finke said. “What will be the consequences for pest herbivores? Those predators are a huge component of controlling pests. They provide that service for us – for free. Also, if we lose those predators, what are the consequences for the plants that we care about? Those are just a couple of the questions that I have addressed with my research.”

Insects can not only put a dent in a crop, they also can put a dent in a producer’s checkbook. Dealing with those insects happens in numerous ways, including the spraying of insecticides. That’s where predator insects come into play. The predators help control pest populations, such as aphids, that can wreak havoc on crops, without the same threat to the environment as chemical control.

There are numerous predatory insects, such as ladybugs, lacewings and wasps. Those insects are split into two different categories – generalist predators and parasitoids. Generalist predators, such as ladybugs and lacewings, are very good at eating a wide variety of insects. Parasitoids are more specialized, such as wasps. They lay their eggs in their prey, with the prey eventually being eaten from the inside out.

“The predators do a lot of silent, behind-the-scenes work that you don’t notice or know about until they’re gone,” Finke said.

Because of their location at the top of the insect food chain, predator insects are prone to extinction.

“There’s a great study example in Southeast Asia,” Finke said. “They grow a lot of rice and were having a problem with a pest called the brown planthopper. It was devastating their plants and yields. The first thing they did was spray the crops with chemicals. They were spraying, trying to kill the pest, and the problem was getting worse and worse. Finally, scientists came in and figured out that the chemicals were killing the predators because they move around more and are hunting, meaning they are more exposed. They soon started a new program and restricted pesticides. Once they did that, predator populations built back up and were able to control the problem.”

Predator habitat has also been reduced due to numerous factors. Rebuilding that habitat and providing extra resources is key to creating a healthy predatory insect population.

Finke has been part of numerous research projects. One such project was focused on an insect called the pea aphid. This aphid is famous for its dramatic behavior.

“When this aphid senses a threat, they start raining off of the plant they are on to the ground,” Finke said. “That’s their defensive behavior. Even if one detects a threat, the others follow suit. It’s a risky behavior. Once they’re on the ground, they could dry out and die or be attacked by other predators. They’re willing to do that to avoid the threat of a predator.

“We did a lot of studies – what happens when there is a diverse community? We found that they do drop even in the presence of other organisms, even ones that won’t harm them. It was fascinating to learn.”

Finke, who has been at Mizzou for 10 years, developed an interest in plants when her family moved from Brooklyn, New York, to Kentucky when she was young.

“My mom was enthralled with plants when we moved to Kentucky,” Finke said. “We spent a lot of time talking about plants and looking at plants. When I left for my undergraduate, I was really interested in studying plants.”

Finke earned her bachelor’s in biology from Centre College in Kentucky. She earned her master’s and Ph.D. in entomology from the University of Maryland. The focus on entomology came after Finke took part in a class at Centre College with a plant biologist. The class focused on insect interactions and Finke was soon hooked.

“It was a small class, with just three students in it,” Finke said. “We were able to do a lot of experiments and read a lot of literature. It was extremely interesting.”

Finke’s work with predator insects began with studying spiders at the University of Maryland and continued in her post-doctoral work at Washington State University. She worked with aphids that were attacking turnips. Finke studied wasps that attack those aphids, in turn helping the turnip crop.

Finke is also part of the Interdisciplinary Plant Group at the University of Missouri.

“IPG is a great group of people,” Finke said. “The group helps opens new doors for interactions with a variety of researchers.”

As an associate professor, Finke has studied a number of predatory insects. She has had several of her students work with similar insects as well. Students have researched grasshoppers and pollinators, among others.

“It’s a lot of fun,” Finke said. “Insects do such different and surprising things. There is always something new to be in awe of.”