. Cooperative economic insect report. Insect pests Control United States Periodicals. - 132 - Populations during the first week of July for Yankton, Clay and Turner Counties were 20-30 larvae per plant, with an overall development advanced to 80 percent of the population as larvae and the remaining 20 percent as pupae. Mid-July specimens of the western corn rootworm were being sent to the Department of Entomology, South Dakota State University, from as far west as Lawrence County and north as far as Brookings County. Adults of western corn rootworm were collected in the north central and north
. Cooperative economic insect report. Insect pests Control United States Periodicals. - 132 - Populations during the first week of July for Yankton, Clay and Turner Counties were 20-30 larvae per plant, with an overall development advanced to 80 percent of the population as larvae and the remaining 20 percent as pupae. Mid-July specimens of the western corn rootworm were being sent to the Department of Entomology, South Dakota State University, from as far west as Lawrence County and north as far as Brookings County. Adults of western corn rootworm were collected in the north central and northeast regions of the State by mid-August. As of September 1, 48 of the 65 South Dakota counties were infested with western corn rootworm. Resistance studies were carried out at the Northern Grain Insect Research Laboratory at Brookings. Data showed that this insect had various degrees of resistance to chlorinated hydrocarbon insecticides in the southeast part of South Dakota. DISTRIBUTION OF WESTERN CORN ROOTWORM. Western corn rootworm was recorded in Greenlee County, ARIZONA, for the first time in 1963. Heavy infestations were found in corn and sorghum. Larvae of this species caused little or no damage to corn in areas of COLORADO where it has been a problem in the past due to the use of control measures being applied at planting time or a better use of crop rotation to reduce losses. Adults were active on the foliage and silks at time of pollination in Yuma County and some controls were applied. In WYOMING, western corn rootworm adult populations were not as severe on corn as in 1962. The first specimens were picked up on August 20 in Platte County where the largest infestations were found; counts averaged 6-8 per corn plant. Larval damage by western corn rootworm in MISSOURI was confined to a few counties in the extreme northwest area. The first adult of the season was observed on June 27. Adults were collected for the first time in the following 7 Missouri counties in 1963:
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
