Then again, most of those beans were booked at more than $15 a bushel and keeping yields high has a direct bearing on the bottom line. Management decisions like these are going to get more and more difficult as both these new insects from Asia continue to march on toward one another.

“The unfortunate fact is that many of these fields where kudzu bug is above threshold should have been sprayed a month ago. With R7 as our “safe stage” from kudzu bug and other defoliating pests, it becomes a hard call to know whether to spray kudzu bugs in beans at R6,” says Clemson Entomologist Jeremy Greene.

Things to consider are how long the insects may have been out there, which is hard to know without scouting the fields. Knowing how close the field is to R7 and how much yield can be lost by running a sprayer through a field of soybeans at the R7 growth stage is likewise hard to know.

The challenge is magnified when a grower is evaluating a soybean field in which $15-plus per bushel beans are growing, when R7 is determined by one brown pod on a majority of plants in a field.

Speaking at a recent regional Kudzu Bug Field Day held at the Edisto Agricultural Research and Education Center in Blackville, S.C., Greene says about kudzu bugs, “The good news is, we can kill them. The bad news is that killing them will cost us, and the damage they do in the meantime will cost us even more.”

Bacheler says in North Carolina, “In general our results align with those from Georgia and South Carolina. Pyrethroids and pre-mix products containing pyrethroids are very effective. Remember to stay away from anything with cyfluthrin. Some of these products look good at reduced rates.”

As more and more BMSB move southward and mix with already high populations of kudzu bugs, problems for growers are sure to get worse. The same insecticides will likely work on both species, but sampling methods, thresholds, etc, may be very different.

The trick will be to find the right combination of thresholds, insecticides and other management strategies, and these will come with time.

rroberson@farmpress.com