Article by Jack Bacheler
In many soybean fields, especially late-planted fields following wheat, both podworms and stink bugs may be just warming up. Add in soybean loopers in places – not to be confused with the more harmless green clover worms – and you can get some serious defoliation. The last week in August and first two or three weeks in September can be a period for moderate to high potential stink bug and caterpillar damage in late fields. This year’s large late season corn earworm moth flights and relatively high stink bug levels in many areas of the state suggest that growers and scouts still pay attention to vulnerable fields in the coming weeks. Most light traps showed their highest corn earworm moth counts for the year this past week. Even in Scotland County, this flight showed no sign of abating this past week, as Wednesday’s August 22 two-night count of 472 moths illustrates.
Additional soybean fields were treated this week for kudzu bugs as more nymphs seem to be showing up recently, perhaps due to more egg mass deposition and successful hatching. In some fields, adult levels have declined significantly. In a screening test near the Raldolph/Lee County line this morning, I was surprised to see that we had spectacular adult and nymph kudzu bug control this morning (3-day assessment) with a number of the insecticides containing either bifenthrin or lambda cyhalothrin at three days after spraying. For example, the untreated checks averaged 82 adults and 99 nymphs while Hero (bifenthrin plus cypermethrin) had 0.25 adults and 0.5 nymphs per 25 sweeps. As you will note, the check plots averaged more than 5-fold greater than our suggested treatment threshold of 15 nymphs per 15 sweeps. The importance of scouting for kudzu bug cannot be overemphasized as it’s not difficult (except for the walking!), and many more fields than appear to have sub-economic levels of this new pest.