Think of the 1950s, when America rebounded after World War II and the Korean conflict. The GI Bill has given many veterans unprecedented access to education, and American universities that have donated land have benefited from talented young scientists. The Second World War was also the period when synthetic organic pesticides moved from the laboratory to the field, with new applications in pest control.
The new pesticides were broad spectrum and very effective and could be modified in the laboratory to create new products with slightly different activity spectra. A new era in pest control had begun, wiping out 60 years of fighting rearguard action against the decline in effectiveness of a meager handful of compounds. It was an exhilarating time in pest control.
Despite the incredible success of the new synthetics, many entomologists have begun to see the disadvantages – mainly in the destruction of natural enemies, leading to new pest problems. Even in these early days, pesticide resistance was a problem. By the late 1950s, pink glasses were no longer pink as the unintended consequences began to manifest.
The realization of these phenomena and the ecological principles which underlie them have become the birth of the integrated pest management movement. Visionaries of the day (many at the University of California at Berkeley) began to point out the shortcomings of a pesticide-only approach and built the framework for a new way of looking at pest control – taking of awareness that all the components of an agro-ecosystem interacted and must therefore be taken into account in a management program.
Like any new theory, IPM in the 1950s was a bit revolutionary. Scientists trained during this period, imbued with these ideas and principles, were challenged to embark on various cropping systems and put the principles into practice. And that’s exactly what happened in the fruits of trees in the Pacific Northwest, thanks in large part to the work of Washington State University entomologists Stan Hoyt and Everett Burts.
Stan graduated from UC Berkeley, the melting pot of IPM, in 1957, just as the theory of IPM was taking shape. He made a stint in the Korean War in a MASH unit working on haemorrhagic fever vectors and returned to Berkeley to complete his degree. His goal was forest entomology, but there were more opportunities in tree fruits, so he completed a doctorate on woolly apple aphid with entomologist Harold Madsen.
Because of his experience with tree fruits, he was hired by WSU to work at the Tree Fruit Research Center in Wenatchee. He has worked on all apple pests, but one situation has caught his attention: the influence of the codling moth program on spider mites. In the mid-1960s, he began to introduce his new (radical) idea to the Washington fruit industry: that insecticides (and miticides) were the problem, not the solution, and that only predatory mites (” typhus “) could keep harmful mites below levels that caused injury.
The development of coding and apple thinning programs is part of the new integrated approach. But it took a bad year of frost, when there was not enough harvest to deserve a spray, it really proved the point: less is more when it comes to IPM. The idea took root and developed throughout the 1970s, until it became the norm for apple growers. In the mid-1980s, producers and consultants proactively protected their typhus and boasted that they had not sprayed mites for 25 years. Despite the periodic disruptions caused by new pesticides, the program still works today.
Stan Hoyt was born in 1927 in Oakland, California, and raised in the Bay Area. He studied entomology as an undergraduate at the University of California, Berkeley, and after touring the Korean War, returned to complete a doctorate in 1957, with Harold Madsen. He began his career at the WSU Tree Fruit Research Center in Wenatchee in the fall of 1957. He was director from 1983 until his retirement in 1993.
Stan passed away on November 30, 2019. He is survived by his wife, Beverley Hoyt; her daughter, Kathleen (Mike Kentley) Hoyt; grandson, Kieran; son, David (Chris) Hoyt; granddaughter, Ariana; and his brother, Jim Hoyt. He was preceded in death by his daughter Kristine Hoyt.
The pear psyllid has not always been the bane of pear growers in the Pacific Northwest. Introduced from Eurasia in the 1800s, the psyllid was detected in the Spokane region in 1939, marking the start of a devastating march through the pear orchards of the northwest.
The relatively new organophosphate and organochlorine insecticides had stopped working due to the development of resistance in 1958, the year Everett Burts began his work as a pear entomologist at the Tree Fruit Research Center at the Washington State University at Wenatchee. Over the next 36 years, Burts worked to find both short-term and long-term solutions for the psyllid, motivated by the insect’s history of developing resistance.
Those who have worked closely with him remember his contributions in areas such as: the introduction of region-wide psylla control programs; the challenge of incorporating newly registered insecticides into existing control programs; use of natural enemies to control the pear psylla; processing threshold sampling; and the role that cultural control measures such as washing trees, eliminating shoots and fertilizer programs could play in suppressing psyllid.
While his work has gained worldwide recognition, Everett has also understood the importance of helping people understand how to best apply this research. Pear industry leaders remember that he provided this information with calm kindness and patience. It was this combination of technical expertise and commitment to awareness that helped create in the 1990s what longtime Blue Star Growers horticulturalist Greg Rains called “the golden age of the fight against pear pests ”.
Everett Burts was born in 1931 and raised in Horse Lake, west of Wenatchee, Washington. He attended public schools in Wenatchee and spent a year at Wenatchee Valley College before attending and graduating from Washington State College. He then continued his studies at Oregon State College, completing his doctorate in 1958 and returning to Wenatchee to work at Washington State University until his retirement in 1994.
Everett died on November 17, 2019. He is survived by Willow Burts, his 65-year-old wife, and two sons, James (Julanne) and Doug (Janet) and their families.
Burts’ original property is now part of the 1,500-acre Horse Lake reserve of the Chelan-Douglas Land Trust.
Past, present and future
The early days of IPM were shaped by entomologists of the time. Stan and Everett laid the groundwork for Washington’s fruit industry: conserving beneficial insects, changing spray practices, understanding the underlying horticultural systems – in other words, looking at the big picture. We still embrace and practice these concepts today, and as a new generation gets started, they will know what they are aiming for. And they will improve it in a way that we have not yet discovered.
—By Betsy Beers and Mike Willett
Betsy Beers is a professor and entomologist at the Tree Fruit Research and Extension Center at Washington State University in Wenatchee. Mike Willett has worked for Oregon State University, Washington State University and directly for the fruit industry in the Pacific Northwest over a 40-year career.