Army worm invasion discovered for second year in county
Published 12:00 am Sunday, July 18, 2010
I received notification from other county agents in Mississippi a few weeks ago about early problems with army worms invading pastures.
And, unfortunately, last week we had two confirmed reports of army worm activity in Adams County. Neither site had enough worms to require spraying but this is a warning to be prepared should you have the problem arise.
So let’s address some questions relating to lawn and field maintenance that are relevant to our area.
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Q: If I had army worms last year will they likely come back this year?
A: I would certainly be scouting my place if I had heavy army worm populations last year. In the winter army worms go underground and pupate and reemerge the following year to start a new life cycle. Therefore the probability of problems reoccurring will often increase in areas of previous heavy infestations.
The army worm is the caterpillar life stage of a moth, which can lay thousands of eggs in turf to emerge into more army worms. These caterpillars are most active at night but can be seen in the daytime feeding or hiding just above the soil surface.
Q: How can I control army worms?
A: When identified at the onset of problems army worms are easy to control. Any product with active ingredients like carbaryl, permethrin or lambda-cyhalothrin will give quick results. There are several traditional fall armyworm products, like Sevin, Kasio and Malathion, that are still available that provide rapid elimination, but there are also several new products that are cheaper, more effective, provide longer residual control and have more favorable pre-harvest intervals for hay harvest. These products include the insect growth regulators Intrepid and Dimilin, as well as Tracer and several pyrethroid insecticides.
MSU Extension forage specialists recommend chemical control measures when population numbers exceed 5-7 army worms per square foot. You can contact our office for a full list of army worm control products with formulation info, grazing restrictions, and harvest intervals.
Q: How can I ever eliminate smut grass?
A: We have been dealing with smut grass predominately in pastures and fields for some time now with little positive relief. The primary chemical labeled for smut grass control has always had a 40 day grazing and forging restriction. Well after four years of research, MSU received notification that the grazing interval for Velpar had been reduced to 0 days for applications up to 4.5 pints per acre Velpar Liquid or 1.875 pound Velpar DF to bermudagrass or bahiagrass pastures for smutgrass control or for any rate applied as a basal bark treatment for woody plant control in pastures.
This is great news for those of us needing smut grass control in grazing pastures. This zero day interval only applies to grazing; there will still be a 14 to 38 day interval restriction for cutting hay, depending on the rate applied.
Please remember to always read the label before using any type of chemical control whether it be fungicide, pesticide, or herbicide.
I have not had any calls yet this year about chemical damage from mixing herbicides behind other products, so please remain cautious whenever using chemicals of any kind for home defense or weed control.
David Carter is the director of the Adams County Extension Service. He can be reached at 601-445-8201.