Armyworms: A Silent Risk to Pastures and Meadows
Dr. Mario A. Villarino, County Extension Agent, Hopkins County
Last week I got a phone call related to armyworms affecting pastures. Mr. Jones (last name changed intentionally) was concerned about his newly planted rye grass and the presence of armyworms in other meadows. When referring to armyworms, Chris Sansone, Rick Minzenmayer and John Jackman wrote “Armyworm outbreaks are difficult to predict but infestations seem to occur in portions of the state every year especially after rains in the early fall. Common species of armyworms present in Texas include: the fall armyworm, Spodoptera frugiperda; the yellowstriped armyworm, Spodoptera ornithogalli; the beet armyworm, Spodoptera exigua; and the armyworm, Pseudaletia unipuncta . The fall armyworm is usually the species that causes the most problems in pastures, small grains and turfgrass”. It is my experience that the fall armyworm is by far a major pest in hay meadows and pastures in Hopkins County. Armywoms are larval stages of moths. The larvae hatch and grows quickly feeding of plant tissue. Their numbers move while feeding acting as an army, since the popular name of the pest. Armyworms are easy to identify because they come in big numbers, moving from place to place with a big yellow inverted “y” over their eyes. The larvae are small at the beginning but grow bigger quickly. Mr. Jones had seen the armyworms before but did not know when to start acting against them. My recommendation was to watch the outbreak, band spray newly planted pastured spraying the perimeter of the area to protect and spray insecticides to control the outbreak. Usually armyworms outbreaks do not last too long (48-72 hrs) with the larvae (caterpillars) being the most devastating stage of the outbreak. Armyworms can be easily killed with insecticides but the beginning of the outbreaks are hard to predict. Most of the time, like in the case of Mr. Jones, producers tend react once the army worms are creating damage. Usually insecticide choices vary with the crop but the following (with product names and grazing restrictions in parentheses) are labeled for use in pastures include carbaryl (Sevin®) (14 days), malathion (0 days), methomyl (Lannate®) (7 days), methyl parathion (Penncap®-M) (15 days) and various biologicals such as Dipel®(0 days). Insecticide labeled in lawns and turf include halofenozide (Mach® 2), bifenthrin (Talstar®), cyfluthrin (Tempo®, Bayer Advanced®), carbaryl (Sevin®) permethrin (multiple brands) and spinosad (Conserve® and others). Check with my office about pricing, since there are big differences in cost per acre treated between products. For more information in this or other topics please call 903-885-3443.
Program Updates: Our yearly Dairy Outreach Program Area Training will be conducted at the SouthWest Dairy Museum October 31, 2012. Permitted Dairies are encouraged to participate. 4 DOPA credits will be offered. The cost of the training will be $10 per person lunch included. Our yearly pesticide applicator training is scheduled for November 7, 2012 at the regional civic center. The topics for this year are of special interest for herbicide applicators and beef producers. Call the Hopkins County Extension Office for more details. The cost of the event is $25 lunch included. New pesticide applicator applicants are encouraged to participate in our multi-county pesticide applicator training scheduled for November 7, 2012. Private landowners seeking pesticide applicator licensing will have an opportunity to get the mandated training and exam in our single day. The cost of the PAT training is $10. No lunch is included. For more information on these or any agricultural topics please contact the Hopkins County Extension Office at 903-885-3443 or e-mail me at firstname.lastname@example.org.