Think back to the 1950s, when America was bouncing back from World War II and the Korean conflict. The GI Bill gave many veterans unprecedented access to education, and America’s land grant universities were the beneficiaries of talented young scientists. WWII was also the period where synthetic organic pesticides went from the laboratory to the field, with newfound applications in pest control.

Elizabeth (Betsy) Beers
Elizabeth (Betsy) Beers

The new pesticides were broad spectrum and highly effective and could be tweaked in the lab to create new products with slightly different spectrums of activity. A new era in pest control had begun, erasing 60 years of fighting a rear-guard action against declining efficacy of a meager handful of compounds. It was a heady time in pest control.

Despite the incredible success of the new synthetics, many entomologists began to see the downsides — mostly in the destruction of natural enemies, leading to renewed pest problems. Even in those early days, pesticide resistance was an issue. By the late 1950s, the rose-colored glasses were no longer rosy as the unintended consequences began to manifest themselves.

Mike Willett
Mike Willett

The realization of these phenomena, and the ecological principles which underlaid them, became the birth of the integrated pest management movement. The visionaries of the time (many at the University of California, Berkeley) began to point out the deficiencies of a solely pesticide-based approach and built the framework of a new way of looking at pest management — the realization that all of the components of an agroecosystem interacted and, therefore, must be taken into account in a management program. 

Like any new theory, IPM in the 1950s was a bit revolutionary. The scientists being trained during this period, infused with these ideas and principles, were challenged to go forth into various cropping systems and turn the principles into practice. And that is exactly what happened in Pacific Northwest tree fruits, thanks in large part to the work of Washington State University entomologists Stan Hoyt and Everett Burts.

Stan Hoyt

Stan graduated from UC Berkeley, the crucible of IPM, in 1957, just as the theory of IPM was taking form. He did a stint in the Korean War in a MASH unit working on hemorrhagic fever vectors and returned to Berkeley to finish his degree. His goal was forest entomology, but the opportunities were more plentiful in tree fruits, and so he completed a doctorate on woolly apple aphid, with entomologist Harold Madsen. 

Stan Hoyt explains integrated mite control. (Wenatchee World, 1967)

Because of his tree fruit experience, he was hired by WSU to work at the Tree Fruit Research Center in Wenatchee. He worked on all pests of apples, but one situation captured his attention: the influence of the codling moth program on spider mites. By the mid-1960s, he began pitching his (radical) new idea to the Washington tree fruit industry: that insecticides (and miticides) were the problem, not the solution, and that left alone, predatory mites (“typhs”) could keep pest mites below levels that caused injury.

Finessing the codling moth and apple thinning programs was part of the new integrated approach. But it took a bad frost year, when there wasn’t enough of a crop to merit spraying, that really proved the point: Less is more when it comes to integrated mite control. The idea took hold and expanded throughout the 1970s, until it became the norm for apple growers. By the mid-1980s, growers and consultants were proactively protecting their typhs and bragging that they had not sprayed for mites in 25 years. Despite periodic disruption by new pesticides, the program still works today.

Stan Hoyt was born in 1927 in Oakland, California, and grew up in the Bay Area. He studied entomology as an undergraduate at the University of California, Berkeley, and after a tour in the Korean War, returned to complete a doctorate in 1957, with Harold Madsen. He began his career at WSU’s Tree Fruit Research Center in Wenatchee in the fall of 1957. He served as director from 1983 until his retirement in 1993.

Stan passed away on Nov. 30, 2019. He is survived by his wife, Beverley Hoyt; daughter, Kathleen (Mike Kentley) Hoyt; grandson, Kieran; son, David (Chris) Hoyt; granddaughter, Ariana; and brother, Jim Hoyt. He was preceded in death by daughter Kristine Hoyt.

Everett Burts

Pear psylla has not always been the scourge of Pacific Northwest pear growers. Introduced from Eurasia in the 1800s, psylla was detected in the Spokane area in 1939, marking the beginning of a devastating march through Northwest pear orchards.

Everett Burts, right, and Bill Rushmore (WSU Cooperative Extension) inspect a beating tray for pear psylla. (Wenatchee World, 1969)

Both the relatively new organophosphate and the organochlorine insecticides had stopped working due to resistance development by 1958, the year Everett Burts began his work as the pear entomologist at Washington State University’s Tree Fruit Research Center in Wenatchee. For the next 36 years, Burts worked to find both short-term fixes and long-term solutions for psylla, driven by the insect’s history of developing resistance.

Those who worked closely with him recall his contributions in areas such as: the introduction of areawide control programs for psylla; the challenge of fitting newly registered insecticides into existing control programs; utilization of natural enemies to control pear psylla; sampling treatment thresholds; and the role that cultural control measures such as tree washing, shoot removal and fertilizer programs could play in suppressing psylla. 

While his work gained global recognition, Everett also understood the importance of helping people understand how best to apply this research. Pear industry leaders recall that he provided this information with a calm kindness and patience. It was this combination of technical expertise and commitment to outreach that helped to create in the 1990s what longtime Blue Star Growers horticulturist Greg Rains calls “the golden age of pear pest management.”

Everett Burts was born in 1931 and grew up at Horse Lake, west of Wenatchee, Washington. He attended the Wenatchee public schools and spent a year at Wenatchee Valley College before attending and graduating from Washington State College. He then went on to Oregon State College, completing his doctorate in 1958 and returning to Wenatchee to work for Washington State University until his retirement in 1994.

Everett passed away on Nov. 17, 2019. He is survived by Willow Burts, his wife of 65 years, along with two sons, James (Julanne) and Doug (Janet) and their families.

The original Burts homestead is now part of the Chelan-Douglas Land Trust’s 1,500-acre Horse Lake Reserve.

Past, present and future

The early days of IPM were shaped by the entomologists of the time. Stan and Everett laid the foundations for the Washington tree fruit industry: conserving beneficial insects, modifying spray practices, understanding the underlying horticultural systems — in other words, seeing the big picture. We still embrace and practice these concepts today, and as a new generation comes up to bat, they will know what they are aiming at. And, they will improve on it in ways we have yet to discover. 

—by Betsy Beers and Mike Willett

Betsy Beers is a professor and entomologist at Washington State University’s Tree Fruit Research and Extension Center in Wenatchee. Mike Willett worked for Oregon State University, Washington State University and directly for the Pacific Northwest tree fruit industry over a 40-year career.