Environmental groups appear to be setting their sights on the neonicotinoid class of insecticides and other pesticide compounds as the main culprits in honey bee population declines. The evidence the insecticides are the main cause is sketchy. The loss of such insecticides would put many cotton farmers in an unprofitable situation.
Jeff Gore, research entomologist at Mississippi State University’s Delta Research and Extension Center, was one of a group of Extension and university entomologists who talked about the group’s efforts to unravel some of the mysteries in the decline of bee populations during a special session at the Consultants Conference at this year’s Beltwide Cotton Conferences.
Scientists at the Delta Research and Extension Center conducted a trial with cotton treated with no neonicotinoid insecticide seed treatments, with neonicotinoid ISTs and with a neonicotinoid IST plus Transform, a new plant bug insecticide registered in cotton.
“In the two treatments where we used neonicotinoid seed treatments we had to make one foliar insecticide application for thrips,” said Gore. “Where we didn’t use a neonicotinoid we made three foliar insecticide applications for thrips.”
For plant bug control, more sprays were required across the board: six where they used neonicotinoid insecticide seed treatments; seven where they did not and seven where they applied neonicotinoid seed treatments followed by applications of Transform.
“Those applications occurred throughout the season, and they were right along with the state average for those sprayings for tarnished plant,” said Gore. (Earlier in the presentation, he indicated plant bugs have become the most important insect in Mid-South cotton production following the adoption of cotton containing the Bt resistance trait.)
“The attack has been on neonicotinoids, and the study indicated we used more insecticides where we didn’t apply them. As you can see (referring to a slide), where we didn’t use neonicotinoids we applied about twice as much active ingredient across all those insecticides applied to those plots.”
Gore also talked about the value of the neonicotinoid insecticide seed treatments. “Where we didn’t use the neonics we spent a lot more money ($186.14 vs. $99.22 and $114.66) than we spent where we used neonics.”