. Cooperative economic insect report. Beneficial insects; Insect pests. - 121 - made in 72 counties, showed the percent of infested plants to range from 0 to 100 and the number of borers per 100 plants to range from 0 to 329. This fall count was approximately one-half the population and percent infestation of the 1960 survey which averaged 56 borers per 100 plants and 38 percent of the plants infested. In MISSOURI, pupation of overwintering larvae was complete and emergence of adults nearly complete in the southeastern area by the last week of May. The adult flight peaked in the central and no
. Cooperative economic insect report. Beneficial insects; Insect pests. - 121 - made in 72 counties, showed the percent of infested plants to range from 0 to 100 and the number of borers per 100 plants to range from 0 to 329. This fall count was approximately one-half the population and percent infestation of the 1960 survey which averaged 56 borers per 100 plants and 38 percent of the plants infested. In MISSOURI, pupation of overwintering larvae was complete and emergence of adults nearly complete in the southeastern area by the last week of May. The adult flight peaked in the central and northern areas by mid-June. During late June and early July, infestations ranging from 5 to 95 percent of the plants showing feeding scars, were observed in the central and northwestern areas of the State. By early July, 5 to 10 percent of the larvae had entered the stalks and controls were considerably less effective. During the last week of July, 10 to 25 pupae and full-grown larvae per 100 plants were observed in the central and north central areas of Missouri. In the southeast area, during the last week of July, first, second and third instars of the second generation could be found. The results of the fall survey showed that the percent infestations was up from 36 in 1960 to in 1961, and the larvae per 100 plants was down from 61 in 1960 to 38 in 1961. European corn borer populations were at the lowest level noted for several years in KANSAS and populations continued at a noneconomic level in infested fields in OKLAHOMA. In ARKANSAS, the percentage of infested stalks and the number of overwintering larvae were lower than in 1960. Very late-planted corn in the northern area was not heavily infested. Only a partial third generation occurred in Ai'kansas. The European corn borer survey that was conducted in WYOMING, by the Wyoming State Department of Agriculture, revealed no infestations present. This was the second consecutive year that surveys have failed to find the pes
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