Date of this Version
Insecticide and Acaracide Tests 15:175-176
The insecticides were applied to 2 fields, one in Saunders Co., Neb., (1986 and 1987) and the other in Cass Co., Neb. (1987 only). Both were seed production fields of'Pawnee' big bluestem which were planted in rows spaced 3.5 ft apart and cultivated annually to maintain row spacing. The insecticides were single applications of Furadan 4 F (carbofuran) and Orthene (acephate) at the rate of 1.0 lb/A in 6 gal/acre water at early anthesis. The insecticides were applied with a C02 activated pressure, knapsack sprayer equipped with a 5 ft boom. Applications were made on either 16 or 17 Jul in both yr and at both locations. The experimental design was a RCB with 4 replications at each site. Each plot consisted of six 30 ft rows. The center 2 rows of each plot were harvested for seed by removing the upper portions of the raceme bearing culms with hand sickles during the last week of Sep. The harvested material was then threshed with a small plot thresher. The midge population was sampled by collecting 25 raceme bearing culms from each plot the first week of Aug and again during the first week of Sep at both locations in 1987. The culms were taken to the laboratory and placed in water-filled flasks, which were enclosed in dark insect rearing cages. Insects emerging from the florets were collected in glass vials (light traps) inserted in the sides of the cages.