WENATCHEE, Wash. — In Australia, Tobin Northfield was on a team of scientists who found cocoa yields could be doubled by using cocoa waste to boost pollinators and natural insect predators.
Now he’s the newest assistant professor and entomologist at the Washington State University Tree Fruit Research and Extension Center in Wenatchee, where a career of innovation awaits him. The brown marmorated stink bug, spotted wing drosophila and codling moth are among the ongoing challenging pests facing the region’s growers.
Northfield, 37, was born and raised in Enumclaw, Wash., and in 2003 received his bachelor’s degree in biology from Pacific Lutheran University in Tacoma.
While in college, he planned to be a dentist but he enjoyed biology and during an entomology class decided “it was way too much fun to do anything else.”
“I was also inspired by all the benefits to society that entomology can bring, like medical and agricultural improvements,” he said.
His interest in science was aided by his father being a forester and his mother being a speech therapist.
He earned a master’s degree in entomology at the University of Florida in 2005 and spent the next two years as a research associate there.
A key focus was studying how Pierce’s Disease, deadly in grapevines, is spread by the Glassy-winged sharpshooter, a large leafhopper, that sucks xylem fluid, mostly water and nitrogen, out of plants and spreads bacterium. He also studied the spread of stink bugs from peanuts to cotton.
Northfield returned to Washington and in 2011 received his doctorate from WSU and a master’s degree in statistics. He had a USDA post-doctoral fellowship in entomology and biological control at the University of Wisconsin and in 2013 took a staff position at James Cook University in Cairns, Australia.
‘Fruit of the gods’
Cocao trees and beans, from which chocolate is derived, were cultivated in Central and South America as a “fruit of the gods,” long before the Spanish arrival in North America in 1492.
The beans grow inside pods that look somewhat like papaya, ranging in size from a softball to a youth football. Beans are harvested from the pods or husks, and that waste is seldom left in orchards.
But an Australia grower wondered what would happen if husks were left in orchards and talked about it with a student at James Cook University. The student came to Northfield, who looked into it and found just one study in Africa showing cocoa husks increasing pollinators but not discussing yields.
Northfield began field trials of letting husks rot at the base of cocao trees in 2014. It resulted in a proliferation of midges, tiny flies, that then increased the pollination of cocao flowers 10-fold, doubling and even tripling the yields of cocao fruit.
“The original idea was that of an Australian cocao grower. So lesson learned was listen to growers,” Northfield said.
The rotting husks also increased lizards and spiders that serve as natural predators to other insect pests, he said. And as natural mulch, the husks add to soil quality.
The study is continuing to see if substances other than the husks can be used to increase the midges.
Northfield was planning to stay in Australia but “couldn’t pass up” the opportunity to move closer to home when an entomology position at the Tree Fruit Research and Extension Center was advertised earlier this year. It was the position once held by Jay Brunner, former center director, who retired in 2015.
Northfield applied, was hired and moved his family to Wenatchee in early August and began work at the center on Aug. 16. His wife, Kirsten, also grew up in Cle Elum, and they have a son, Micaiah, 3.
Northfield will work in integrated pest management of tree fruit pests. It’s a long-practiced holistic approach that relies on beneficial insects, predators’ habitat changes and other eco-friendly techniques to manage pests. Tools also include selective use of pesticides and biological controls such as the mating disruption of codling moth.
Northfield’s statistics background will be used in improving WSU’s Decision Aid System used by growers in the U.S. and Canada. DAS uses current and historic weather data from WSU’s AgWeatherNet to drive insect and disease models to help growers know when to combat pests and diseases.
Northfield plans to learn as much as he can from the center’s more experienced entomologists, Elizabeth Beers and Vince Jones. He also will learn from other professors, consultants and growers.
“The size and shape of trees, trellises, shade netting, mulches — they all may influence pest or predator behavior,” Northfield said. “I’d like to focus on system levels management and how that alters pest abundance. If you focus on just one pest and ignore others you may end up with a whack-a-mole situation where you knock down one and something else pops up. We want to look at the broader picture which is not easy to do.
“When you look at the experience at the center it’s pretty amazing. I’m really thrilled to be here.”
Born and raised: Enumclaw, Wash.
Family: Wife, Kirsten; son, Micaiah, 3.
Education: Graduated from Enumclaw High School, 1999; bachelor’s degree in biology, Pacific Lutheran University, 2003; master’s degree in entomology, University of Florida, 2005; master’s in statistics and doctorate in entomology, Washington State University, 2011.
Occupation: Assistant professor of entomology, Washington State University Tree Fruit Research and Extension Center, Wenatchee.
Work History: Assistant professor of entomology, James Cook University, Cairns, Australia, 2013 to 2018; USDA post-doctoral fellowship, University of Wisconsin, 2012.