This year there were several first-time-evers with insect pests in the Virginia soybean crop. We found brown marmorated stink bugs (BMSB) in soybean fields in 44 counties — more than half of the major soybean growing counties that range from northern Virginia to the North Carolina border. For the first time, we found BMSBs in soybean fields in our coastal plan region and in two counties that grow cotton. And importantly, a BMSB nymph was found in a cotton field, which we think is the first ever reported in the U.S.
The kudzu bug also gave us some first-time-evers. In 2011, one kudzu bug nymph was found in kudzu late in the season in only one county bordering North Carolina. This year, we found our first kudzu bug adults, and by mid-season, adults were found in soybean fields in 19 counties. We also found the first kudzu bug nymphs in soybean, and we found both kudzu bugs and BMSBs in the same soybean fields in eight different counties.
I personally do not recall ever seeing this many first-time-evers in one season. I feel like we are in an insect pest war zone, now confronted by two relatively new pest species — BMSBs moving down from the north, and kudzu bugs moving rapidly up from the south. Correct me if I am wrong, but I think Virginia is unique in this challenge among all other soybean-growing states.
So what are doing about it? We ramped up our statewide surveillance efforts to include three field scouts, one located in the Suffolk area in the southeast, one in the mid-central part of the state, and one in the north central area. These dedicated folks have been regularly checking soybean fields, talking with growers, tracking the need for protective insecticide applications, and rechecking treated fields to see how well treatments held.
Updates were posted weekly to our Virginia Ag Pest Advisory, which is hosted and supported by the Southern Region IPM Center in Raleigh, NC, and goes out to more than 300 email recipients across the state and region. This field surveillance effort has been expensive to operate including wages, fuel, mileage costs, vehicle rental, and per diem reimbursements and could not have been done without the support of several sources. I want to recognize these agencies and let them know that their support has been invaluable in allowing us to track the occurrence and extent of these invasive pests in our soybean crop and to provide growers with critical information to help manage these pests to minimize crop losses. Thanks go out to the Virginia Soybean Board, the United Soybean Board, and the USDA-NIFA Extension IPM grants program.
Virginia growers plant between 500,000 and 600,000 acres of soybean each year, netting farm cash receipts of almost $250 million. Although maybe not the most important consideration for growers, insect pest management is certainly on their to-do list. In addition to our surveillance program, we are working in collaboration with entomologists at the universities of Delaware and Maryland to develop more information on managing BMSBs in soybean. Together, we are working on finding better sampling procedures, treatment thresholds, application tactics, and last but not least, what insecticides work best to control them. This is slow tedious work but we are making progress on many fronts. Our hope is that after we crunch all the 2012 data and meet to discuss our findings, we will be able to roll out some new management recommendations.
In terms of the kudzu bug, we will look to the south for that information. The entomologists in the kudzu bug epicenter — Georgia, South Carolina, and North Carolina — are working hard to provide the same good information on kudzu bug management in soybean. We won’t need to reinvent that wheel — just bring up their good information to share with our growers.
— Ames Herbert, Extension entomologist