Woolly bear caterpillars: Woolly bear caterpillars were abundant in many parts of the state in 2018, starting in July and continuing into September. Many were killed by fungal diseases during periods of wet weather. Treatment decisions based on overall defoliation levels (more than 20% defoliation in reproductive soybeans) should be used to manage these and other defoliating insects in soybeans.
Western bean cutworms (Figure 1): High populations of western bean cutworms were seen in many parts of the state in 2018. Decreased susceptibility of western bean cutworm larvae to the Cry1F Bt protein in some Bt corn has been documented in Nebraska and other states. These hybrids should be scouted and treated with an insecticide when thresholds are exceeded. More
Dectes soybean stem borer (Figure 2): This insect continues to slowly expand its range in Nebraska. The first evidence of Dectes in soybean in Nebraska occurred in 2000 just across the Kansas border near Highway 81. Now found in soybeans in much of southcentral Nebraska. Larval tunneling in the base of the plant predisposes the plant to breaking near the soil surface. Timely harvest of heavily infested fields is recommended to limit harvest losses.More
Handy Bt Trait Table updated: The most current version of this publication is available at https://www.texasinsects.org/bt-corn-trait-table.html This publication provides information on all commercially available Bt corn hybrids, their insect protection and herbicide tolerance traits, IRM requirements, all in a one-page format.
Seed corn maggot (Figure 3): Seed corn maggot was found damaging soybeans in south-central Nebraska. A cover crop mix containing radishes did not winter kill and was tilled in before soybean planting. The decaying plant material attracted the seed corn maggot flies to lay their eggs in the field, and the maggots were able to damage the germinating soybean seeds, which were not treated with an insecticide.
Burrower bugs (Figure 4) in soybeans: Stand loss was seen in a soybean field in Gage County, where small bugs were seen feeding at the base of soybean plants. These were identified as burrower bugs. These insects prefer feeding on mints or nettles. In this case, they initially developed on henbit, a common winter annual mint in Nebraska crop fields. After this was killed by tillage or herbicides, the burrower bugs moved over to feed on soybeans. More
Japanese beetles (Figure 5) continue to expand their range in Nebraska. They can be found as far west as Lincoln County, based on annual surveys by Nebraska Department of Agriculture. They are more commonly being seen in corn and soybean fields, as well as a variety of other crops, trees, and shrubs. Be on the lookout for them in 2019. More
Force 6.5G: Syngenta has labeled a new formulation of its tefluthrin insecticide, Force 6.5G, for control of soil insects in field corn, popcorn, seed corn, and sweet corn. Tefluthrin is an IRAC Group 3, pyrethroid insecticide.