Although we hear rumors of worms in soybean fields, our scouting does not confirm this.  We are finding almost none in either full season or double crop fields—and others are reporting the same.  The full season crop is quickly approaching the ‘safe’ zone, that is, the point where pods are too tough to be attractive to insect pests.  But, the summer is not over yet.  Because corn is slow to dry down this year, we may still see a corn earworm moth flight into soybean fields, and if this happens, double crop fields would be a primary target.  This is also true for stink bugs.  As we get into late summer and early fall, stink bugs will be attracted to double crop fields.  We strongly recommend that you begin checking double crop fields.

Because of the very weak corn earworm moth flight, we have not been able to capture and test nearly as many moths for pyrethroid tolerance as we have in the past.  But all indications are that levels are high (see the graph below).  In the most recent sample more than 40% survived the vial challenge.  If this high pyrethroid tolerance level coincided with a large flight the large numbers of worms in fields, we would no question be recommending non-pyrethroids.  But with this weak flight and the low numbers of worms in fields, I think we can get decent enough control with high rates of pyrethroids, alone.

We are still finding BMSB and KB in new places—7 new counties for BMSB (Sussex, Albemarle, Cumberland, New Kent, King George, Isle of Wight, and Surry), and KB in 3 new counties (Mathews, Mecklenburg, and Virginia Beach)—but numbers in all locations are way down compared with last year (see the maps below).  No fields are at threshold for either pest, but a couple of fields were identified in James City County that have some infested edges.  The full season crop is going to be safe from injury soon, when plants grow through the R6 stage.  As the season moves into late summer and early fall, double crop fields will provide one of the few good late season food sources for all stink bug species—so they will need to scouted until they are safe from injury.

BMSB was found in soybean in nine new Virginia counties this past week:  James City, Caroline, Stafford, Culpeper, Fauquier, Nelson, Rockbridge, Henry, and Montgomery.  The highest numbers of BMSB occurred in a Warren field (5 nymphs and 4 adults per 2-minute visual inspection), followed by Augusta (5 nymphs and 1 adult per 2-minute visual), Fauquier (5 nymphs), Buckingham (4 nymphs), James City (3 nymphs, 1 adult), and Appomattox (3 nymphs, 1 adult).  Thanks to our soybean scouts and to Dr. Tom Kuhar for their updates this week.

Our soybean scouts detected kudzu bug in two new Virginia counties this past week (Halifax and Greene); both of these locations had low numbers.  The highest numbers of kudzu bugs reported by our scouts for the past week were in a Pittsylvania soybean field (8 nymphs and 3 adults per 15 sweeps), followed by Goochland (4 adults per 15 sweeps) and Henry (3 nymphs and 2 adults per 15 sweeps).  Additionally, VCE Agent Scott Reiter reported high numbers of kudzu bug adults along the edge in a Prince George soybean field that was bordered by kudzu (50 adults in 15 sweeps in the first 30 feet of field, diminishing to 3-4 adults per 15 sweeps at 100 feet from the field edge).  Scott found other fields with 0-3 kudzu bugs in 15 sweeps.

We are providing updated maps of the distribution of kudzu bug and brown marmorated stink bug in Virginia.  Although we have added a few new counties since last week, overall the populations of both of these pests are very low compared with last year.  To our knowledge, no soybean fields have even come close to reaching threatening levels or thresholds.

Most kudzu bug egg masses that we are finding have already hatched indicating that the second generation is occurring.  This pest has only two generations so if this second generation stays small, as it appears, we may not have to treat any fields this year.

Brown marmorated stink bug levels are very low.  Although a few can be found in many fields, none are reaching high levels.  All of this is good news for growers.  But, the season is far from over so stay vigilant.