Monday, May 7, 2012

Grasshoppers and Pill Bugs in Cotton

The most common concern in cotton insects continues to be grasshoppers. The most significant change in the past 2-3 weeks is the fact that a percent of the population now are adult grasshoppers. Adults are much more difficult to control so current recommendations call for higher rates of whatever insecticide chosen. Several consultants are now applying one of the least expensive pyrethroids at higher labeled rates. Even then, a small percent of the adult population will escape controls.

Growers should be reminded that cotton planted in April with seed treatments will profit from foliar insecticides at the 1st true leaf stage. This is especially true in conventional tillage dry land situations.

A rare question was received today about controlling pill bugs in cotton. This situation usually occurs when cotton is planted in reduced to no-tillage behind corn. Pill bugs seem to only occur in high residue, high organic matter conditions. Little research or experience is available to base a pill bug recommendation on. After several phone calls, the best chemical options seem to be: Bidrin at 0.25-0.33; Orthene at 0.5; or Sevin at 0.5-0.75 lbs per acre. This is a question that will likely occur again on an infrequent basis. Dry weather and high temperatures should help solve this infestation. However, the next 48-72 hours may not present this situation.