Tag Archives: Fall Armyworm

Fall Armyworm Management in Pastures

We are finding Fall Armyworms in many pastures and hay fields. In fields with above threshold numbers, this can reduce the hay yield or grass available for cattle grazing. I use a sweep net to sample and use an economic threshold of 25 worms per 5 sweeps. An alternative threshold is when worm counts exceed 2-3 per square foot. We sprayed an insecticide control trial last Wednesday near Port Lavaca (9/14/22). Results of the trial found most commonly used insecticides worked well. This includes pyrethroids like Lambda-Cyhalothrin, Lambda… Read More →

Fall Armyworms in Bermudagrass Hay Fields

All summer we have seen high numbers of fall armyworms in bermudagrass hayfields and pastures. Last week, I sprayed a Fall Armyworm insecticide control trial in a bermudagrass hayfield near Port Lavaca. To further complicate things, the field received rainfall 3 days after applications. This typifies what we have been experiencing this year. When scouting with a sweep net, we found very high numbers of fall armyworms. Pre-treatment  counts averaged around 250 worms per 5 sweeps. The economic threshold I use is 25 per 5 sweeps. In this… Read More →

Midge in Grain Sorghum

Grain sorghum fields range in maturity from nearing bloom to soft dough and all of these fields need to be scouted frequently. Blooming sorghum is susceptible to sorghum midge and field scouts are finding more midge in the fields this week. Scout sorghum fields 2-3 times per week until past bloom. Start by scouting fields on the south side (downwind) as the midge is a poor flyer and will be found on the field margins first. When you are finding them on field margins, move 150-200 feet into… Read More →

Fall Armyworms in Sorghum

Fall armyworms are being found in sorghum fields across the area this week.  While the feeding can be alarming, I have yet to find a field in need of treatment. Insecticide application may be justified if larval feeding reduces leaf area by more than 30 percent or is damaging the developing grain head or growing point within the whorl. The fields where I have found the armyworms had less than 5% infested plants and the feeding damage was below the economic threshold. Often, I was finding two or… Read More →

Mid-Coast Grain Sorghum Update

Grain sorghum maturity ranges from boot to soft dough.  Some fields are turning color. We are finding varying populations of Sorghum Midge in fields ranging from 0-5 per head.  Treatment thresholds are 0.5-1 midge per head depending on the number of flowering heads per acre. We are finding headworms in Refugio County sorghum fields ranging from 0-4 per head.  Many of these are fall armyworms.  The economic threshold for headworms ranges from 0.15 to 1 large worm (> 0.5 inch) per head.  For medium worms (0.25-0.5 inch) the ET… Read More →