Soybean loopers are now being reported in soybean fields across much of the eastern side of the state. In past years they were mostly confined to southeastern counties. This infestation has broken all the records in terms of intensity (as many as 100+/15 sweeps in some fields) and geography (now being reported from Middle Peninsula and Northern Neck counties). This must be due to the persistent hot, dry weather, and the high percentage of fields previously treated with insecticides.

Loopers are easy to identify but there is some confusion about their color. Soybean loopers have both a ‘green’ and a ‘black’ color phase (see the attached image). We are seeing both color phases in our samples. There may be some cabbage loopers (a completely different species) mixed in, but we have not verified this. There are no exact thresholds for loopers in soybean so treatment should be based on the amount of leaf feeding in relation to the size of the total canopy. But, a very loose rule of thumb could be that 20 or more per 15 sweep net sweeps may constitute a threat. Fewer than that, especially in tall, full canopy fields probably does not constitute a threat. Some fields are getting close to maturity with pods and leaves beginning to yellow. Loopers are not a threat to those fields. Pyrethroids should not be figured into a looper treatment decision. They are less than effective. If stink bugs are present in looper infested fields, I would consider adding Orthene to the looper insecticide. Orthene will provide good control of both green and brown stink bugs where the pyrethroid would miss some of the browns. Oddly, we are seeing more brown stink bugs in some fields than greens, which is opposite of what we are used to seeing.

We have initiated 5 different field trials to evaluate the effectiveness of many different insecticides/rates for loopers. Results will be presented at our annual Pre-Harvest Field Tour scheduled for Sept. 14.
Additional information: soybean-looper-color-phases-herbert-2010-ppt

Although the corn earworm flight is still strong, we are not hearing of many fields with high numbers of worms. However, we are hearing of a lot of fields with pod-stage thresholds and many are being re-sprayed. Several folks have reported seeing newly hatched small worms but are waiting a few days before spraying to see how things develop. Holding off a few more days may mean the difference in having to treat a third time. There are a lot of fields that seem to be holding with no new earworms developing, especially the early planted fields. More infestations are being reported in later-planted double crop fields. This is a typical pattern as the pods in early planted fields are getting to the point where they are no longer attractive or vulnerable. Maybe this second infestation will not be as bad as we expected, but we have another week or two before we will know. Our advice is to keep checking fields at least every 5 days or so, until fields reach the R7 growth stage. As a side note, our pyrethroid testing of adult corn earworms is showing a gradual increase in the level of survivorship, now averaging over 40% for this past week (see the attached figure). Better consider one of the non-pyrethroid options.
We are finding (and hearing about) more soybean loopers. The most we have encountered is about 15 to 20 per 15 sweeps, but even at those numbers, the level of defoliation is not bad or to the point where fields need protection. This may get worse, or may not, depending on a lot of factors.
One of the oddest situations is the extremely large numbers of green cloverworms that are being reported in some areas. Folks are finding 30-40 and more per 15 sweeps and they are definitely working on the foliage. We always see cloverworms in soybean fields but never at these high levels. They are having to be controlled in fields with limited growth (due to slow growth during the hot dry weather).
Reports from Maryland are saying that brown marmorated stink bugs are inundating soybean fields in western and central Maryland. We have known about this pest for several years. It is a native of China, was first reported in Virginia in 2005 (one specimen) and has gradually increased in number. It has become established in Virginia and is now causing problems in vegetable a fruit crops. Soybean is one of its many host crops in China and as we feared, it is now moving into that crop. We have found a few in Virginia soybean fields, about 1 per 15 sweeps in a couple of fields. We do not know much about damage potential or control options but a lot of research is underway.
Additional information: cew-cypermethrin-aug-26-2010-ppt

For August 16-19, Ed Seymore reported that surveyed fields in the following counties had little to no soybean aphids, with the exception of Gloucester in the Wood’s X area: Augusta (0), Albemarle (0), Buckingham (0), Caroline (1-5), Charles City (0), Clark (1-5), Culpeper/Fauquier (6-39) aphids/plant), Gloucester (150-249), Goochland (0), Henrico (0), King and Queen (0), King William (0), Lancaster (0), Mathews (1-5), Middlesex (0), Rockingham (0), and Shenandoah (0). The economic threshold for soybean aphid is 250 aphids/plant. Under ideal conditions, soybean aphid populations can double every 2 days. Very low numbers (about 1 per 15 sweeps) of brown marmorated stink bugs were detected in one soybean field in central Culpeper County.