Issue link: http://read.dmtmag.com/i/56260
Pest Management IPM researcher sees challenges ahead New, invasive pests threaten IPM. by Richard Lehnert W hen Dr. Larry Hull entered the world of land-grant university tree fruit entomolo- gists in 1972, integrated pest management was just the new kid on the block. The idea of IPM was to draw back from the heavy reliance on chemical pesticides and to inte- grate a diverse group of pest control tactics, most of which were just ideas that needed to be developed. Hull began work at The Pennsylvania State University under Professor Dean Asquith, one of the earliest IPM pioneers working in tree fruits, and over the years he and his colleagues developed and helped implement IPM tac- tics like biological control, use of trapping and sampling, decision making based on economic damage thresholds, mating disruption using pheromones, selection of insec- ticides for their lowest possible disruption of natural enemies, and finding the proper rates and timing for insecticide applications. Larry Hull demonstrates the electronic Z-trap for remote monitoring of pests at a recent grower field day. "Everything I did during my career was directed toward the theme of IPM," he said in an interview with Good Fruit Grower. Hull joined the Penn State fruit research team in 1972 as a research assistant, then obtained his doctorate and a place on the entomology department faculty in 1977. At the end of 2011, after 35 years, he decided to hang up his sweep net and spend more time golfing, fishing, and hunting. But he'll keep his office at the Fruit Research and Extension Center in Biglerville, where he was director from 1998 to 2006. "I've got a lot of loose ends to tie up," he said. "I have a number of research programs and papers to finish, but I hope to do it at a slower, less hectic, pace." As he was preparing to retire, fruit growers in the Mid- Atlantic area were facing new challenges. Life was hectic as usual. A threat to IPM "We've got a problem on our hands," Hull said. "The brown marmorated stinkbug is our newest major chal- lenge. We need to control it, but we don't want to destroy 40 years worth of work developing IPM." Unfortunately, some of the the insecticides that best control this invasive new stinkbug are the ones entomol- ogists had not been recommending because they are destructive to the beneficial insects and mites that had been so carefully cultivated during the development of IPM. Is this depressing? While it's certainly not good news, Hull is philosophical. Most of the pests fruit growers con- tend with, like the codling moth and the oriental fruit moth, were introduced species that were initially devas- tating but ultimately were brought under control. This, he expects, will happen with the brown marmorated stinkbug, and with the recently found spotted wing drosophila in Pennsylvania as well, but it won't be easy. "We'll be dealing with these insects for a long time to come," he said. The work to develop IPM has been a long process as well. At one time, it had seemed that chemical insecti- cides would provide a simple solution to the problems of insect damage. One of the first signs that wouldn't work came in the 1960s with the explosion of European red mites and two-spotted spider mites, their populations released from constraint as the insecticides wiped out their natural enemies that had kept them in balance. Early IPM work focused on finding out more about predatory insects like the coccinellid predator, Stethorus punctum, and the predatory mites like Amblyseius fallacis, Agistemus fleschneri, Typhlodromus pyri, and Zetzellia mali, and getting their populations rebuilt so they, not chemical miticides, could control the plant- feeding mites. Another sign was insect resistance to insecticides. Chemical solutions were not permanent and involved a never-ending search for new materials to replace those to which pests gained resistance. OxiDate® 2.0 eradicates Fire Blight on contact, providing an effective alternative to traditional treatment. EPA Registered No mutational resistance Spray through bloom period Exempt from pesticide tolerances - No MRLs Can be rotated with biological based bactericides/fungicides ARM spraying Hull was a strong promoter for the continued devel- opment and implementation of the alternate-row middle (ARM) spraying practice, an idea that came south from Cornell University in the early 1950s. By the end of the 1970s, 95 percent of the spray applications in Pennsylvania apple orchards were made using that method, he said. ARM did several things. Spraying one side of the tree and not the other created a refuge for beneficial mites and insects within each tree so the spray was less disruptive to biological control. Growers would also shorten the interval between sprays, providing fresh insecticide more often. With a shorter interval, growers could also apply insecticides at a lower rate, reducing the overall chemical impact on the environment. Hull and his present colleagues at the research cen- ter—Dr. David Biddinger and Dr. Greg Krawczyk—are currently doing research to see how ARM will work in the 18 MARCH 1, 2012 GOOD FRUIT GROWER www.goodfruit.com courtesy of LArry HuLL OxiDate 2.0 OxiDate 2.0 Fire Blight on Pome FruitsFire Blight on Pome Fruits Controls Contr