The RBSB is a key soybean pest throughout South America and has recently become a significant soybean pest in the extreme southern U.S. Adults emerge from overwintering sites in the spring to look for secondary feeding sites.1 While soybeans are in the vegetative stages of growth, the RBSB's prefer to feed on other legumes and clover.2 Later in the growing season the adults migrate into podding soybeans.3 An estimated four to eight generations of RBSB may occur each year.4
When generations of RBSB overlap, eggs, nymphs, and adults are present simultaneously, making insecticidal control difficult. More importantly, the mobility of the RBSB results in even more complex management decisions, as few labeled insecticides have more than a few days of residual activity are labeled for use in soybean fields. Soybean scouting intervals tend to be on a weekly basis at a minimum and reinfestation can occur after the insecticide has lost its effectiveness. As is the case with other insect pests, rotating insecticide chemical classes is highly recommended for overall efficacy, as well as resistance management.
Accurate identification of RBSB is critical, as the recommended action threshold is lower compared to other stink bugs found in soybean fields (Figure 1). Adults of RBSB are approximately half the size of the common stink bug found in the mid-South (Figure 3). The primary characteristic used to identify the adult is a forward pointing short, fixed spine that arises from the abdomen. No other economically important mid-south stink bug has this characteristic. Because this spine can be hard to see, the RBSB's are often identified by the overall appearance, the adult usually has a single band across the pronotum this is cream colored or red but periodically appears orange to deep purple and appears more slender relative to its width when compared to more common stink bug species such as Green stink bug (GSB) (Figure 2).
The best method for sampling is with a 15-inch diameter sweep net. A good economic threshold is 6 stink bugs in 25 sweeps (Check with your local extension specialist for your specific thresholds). When sampling it is important to sweep deep into the canopy when air temperatures are high because stink bugs move to lower areas of the canopy when hot.
RBSB tends to be a late-season pest. Planting earlier-maturing soybean products during the early planting windows may help manage stink bug populations, regardless of species. RBSB are highly mobile and selective, and often infest later planted fields or those with green pods, while fields planted earlier will likely have a chance to fully mature before stink bug populations arrive.
RBSB is not as susceptible to insecticides as GSB or Southern green stink bug (SGSB). Pyrethroid insecticides are often considered the standard for control of the GSB and SGSB; however, they only provide RBSB suppression when applied alone. The most consistently effective insecticides contain the active ingredient bifenthrin.5 Higher rates of acephate are generally effective, but a mixture of two single active ingredients is highly effective and helps provide for resistance management. For specific for RBSB control measures for your area, contact your local extension specialist.
1Davis, J., Leonard B.R. and Baldwin J. 2010, Stink bug and lepidopteran control in soybean. LSU Ag Center LATMC 2010 Grain Crops Sessions.
2Panissi, A.R., and Slansky, F. 1985. Review of phytophagous pentatomids (Hemiptera: Pentatomidae) associated with soybean in the Americas, Florida Entomologist, 68(1), 184-214.
3Panizzi, A.R., and Smith, J.G. 1977. Biology of Piezodorus guildinii: oviposition, development time, adult sex ratio and longevity. Annals of the Entomological Society of America, 70:(1), 35-39.
4Paxton, K. W., Leonard, B.R., and Lancelos, D. 2007. Redbanded stink bug – A threat to soybean profits? LSU Ag Center Staff Report No. 2007-03.
5University of Arkansas, Division of Agriculture, Publication FSA7078. http://www.uaex.edu.
Web source verified 09/06/17 170911095856