Spring 2008
Grazing Pigs Vs. Plum Curculio

Jim Koan, owner of the 150-acre AlMar Orchards in Clayton Township, Michigan, grazes Berkshire hogs in his organic apple orchard, obtaining almost complete control of plum curculio within a few years. Plum curculios lay eggs in fruits in the spring, and the resultant larvae later cause fruit drop. On the ground, larvae leave the drops and tunnel into the soil, later emerging as adults; but letting pigs eat the drops for three weeks in June eliminates the larvae before that. Chickens and guinea hens grazing in the orchard also reduced curculio populations well, but the birds were subject to predation by owls, coyotes and hawks. In New Zealand, sheep do the same job, but their efficacy has not been studied scientifically. Koan’s grazing piglets also helped control weeds. Michigan State University researchers and Koan will study the method further to determine the best age and number of pigs to graze; the effects of grazing on meat quality; and the economic possibilities for combining hog farming and orcharding. Koan expected to produce about 4,500 to 5,000 pounds of meat from his 27 pigs. (“Hog heaven: Swine fine at pest control,” by Ken Palmer, The Flint Journal, Dec. 8, 2007;

Bacterium from Hemlock Soil Toxic to Insects

A bacterium called Chromobacterium subtsugae that is toxic to Colorado potato beetle larvae is also toxic in varying degrees to gypsy moth, small hive beetle and tobacco hornworm, according to preliminary studies. The USDA has licensed the technology to Marrone Organic Innovations, Inc., of Davis, Calif., and Natural Industries, Inc., of Houston, Texas. Soil rich in decomposed hemlock leaves collected from the Catoctin Mountain region in central Maryland provided the C. subtsugae. Researchers isolated unusual purple colonies of the microbe by suspending samples of forest soil in water and then plating it on growth medium. While tobacco hornworm and gypsy moth weren’t killed by the bacteria, their weights were drastically reduced. The bacterium is also toxic in varying degrees to western corn rootworm, southern corn rootworm, whiteflies and diamondback moth. In July 2007, a patent was granted for use of the bacterium as a biocontrol agent against those pests. (“ARS Licenses Purple Bacteria to Battle Crop Pests,” by Sharon Durham, USDA Agricultural Research Service News Service, Dec. 13, 2007;

Enjoy Maine Trees

The Maine Tree Club teaches people of all ages about trees. Offered by University of Maine Cooperative Extension, the Maine Forest Service and the Pine Tree State Arboretum, the club charges an annual registration fee of $20 per person, $30 per couple, $35 per family and $65 per group of up to 15. Some scholarships are available. The club plans at least three outings in 2008 to get people into the woods for hands-on learning and enjoyment. These outings, along with fact sheets featuring different Maine tree species, teach club members to recognize 50 types of trees over two years. Participants also receive a 10X hand lens, a notebook for the fact sheets, a pocket guide to Maine trees and practical guides about tree growth and care. (“Maine Tree Club Offers Outings and Education,” University of Maine Cooperative Extension press release, Dec. 3, 2007; Amy Witt. For a free informational brochure, contact UMaine Extension, 800-287-1471 or [email protected])

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