Monday, August 20, 2012

Armyworm / Fall armyworm Problems Increase

Doug Johnson, Extension Entomologist, University of Kentucky

Feeding of one or several “armyworm” species appears to be on the increase. I cannot be completely sure which species are causing the damage, and it is likely that two species, the armyworm also know as True armyworm and the fall armyworm are the most likely culprits.

Fall armyworm moth captures in the IPM pheromone baited traps at Princeton, KY have skyrocketed in the last two weeks, going from 0 to 131 and currently to 550 moths captured in the trap week ending 9/16/12. This problem was reported in TN, AR & MS last week and recently in MO.

In addition several people have reported large populations of worms moving from grass to soybeans over the last week in several west KY counties. Just today (8/17/12), one location in Caldwell Co. KY was reported to be infested at a rate of 20 worms per square foot! These are likely the grass feeding strain of the fall armyworm, but unfortunately I have not been able to examine these pests. You should not have great difficulty in controlling these armyworms, but you should continue to check fields after any application. FAW is a migrant species and spends most of its’ time in cotton producing states. So, as a species it is sprayed much more often that most of the insects with which we usually deal. Be wary of a resurgence after a control application.

Regardless of which species of “armyworm” is active in your area the management will be the same. See the article on fall armyworm in the previous issue of Kentucky Pest News newsletter, for control considerations (Johnson, D. Aug. 14, 2012. Fall armyworm flight increases. KPN No. 1314).

Because we are still seeing an increasing capture of moths captures, and the large number of fields with late developing soybeans, this problem is likely to continue for some time.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.