Activity of Insecticides Against Heliothis Spp. Eggs in Mississippi, 1983

A small plot study was conducted at Mississippi State Univ. to evaluate the effects of Zectran, Ambush, and Fundal on Heliothis spp. eggs. Plots were located on the Plant Sci. Res. Farm. Pretreatment observations detected Heliothis spp. eggs on .75% of the plants in the field. All treatments were replicated four times and arranged in a randomized complete block design. Each plot was four rows (38-in. rows) by 60 ft with two buffer rows between plots. Insecticides were applied with a boom-type sprayer calibrated to deliver 6.6 gal/acre at 30 lb/in2 through two TX-4 nozzles/row. Heliothis spp. eggs were collected and placed on egg cards similar to those used in Trichogramma spp. studies. Twenty eggs were collected in each plot and observed under a stereo-microscope at 48 h posttreatment. To distinguish between true ovicidal activity and mortality of neonate larvae, data were recorded on mortality before and after eclosion from the chorion.