. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Seed Orchard Pests. Figure 4. Helicopter apply- ing insecticide to a seed orchard in Brooksville, FL. F-705639 beetles damaged more than 20 percent of the white pine cone crop in 1979. In 1980, this pest destroyed less than 10 percent of the cone crop, or approximately 28 pounds of seed. Approximately 29, 17, and 35 pounds of seed were lost because of cone beetle feeding in 1981, 1982, and
. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Seed Orchard Pests. Figure 4. Helicopter apply- ing insecticide to a seed orchard in Brooksville, FL. F-705639 beetles damaged more than 20 percent of the white pine cone crop in 1979. In 1980, this pest destroyed less than 10 percent of the cone crop, or approximately 28 pounds of seed. Approximately 29, 17, and 35 pounds of seed were lost because of cone beetle feeding in 1981, 1982, and 1983, respectively. As production in- creased during this 5-year period, 10 to 20 percent of the loss was attributed to the lodgepole pine cone borer and the fir coneworm; more than 10 percent of the loss was caused by the western conifer seed bug. California has 206 acres of seed orchards under Federal and State ownership. These orchards make up approximately 2 percent of the total seed orchard acreage in the United States. Federal or- chard plantings of ponderosa pine, Douglas-fir, and rust resis- tant sugar pine are just beginning to produce crops. Coneworm species are currently the key pests in the Sierra Mountains, whereas the Douglas-fir cone moth and the cone gall midge cause the greatest losses of Douglas-fir seed along the coast and in the Siskiyou Mountains. Current evidence sug- gests that the western conifer seed bug and the ponderosa pine cone beetle have the potential to become localized problems. In 1979, approximately 15 per- cent of the potential seed crop was destroyed by the Douglas-fir cone moth, the Douglas-fir cone gall midge, and the fir coneworm. Again in 1980, these pests ac- counted for most of the damage. In addition to the previously men- tioned pests, populations of seed chalcids, ponderosa pine con- eworms, and fir cone maggots in- fested the small 1981 cone crop and destroyed more than 20 per- cent of the potential crop. The Douglas-fir cone crop
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
