Stink bugs are easy insects to identify with their shield–shaped bodies and long, piercing/sucking mouthparts. When crushed, they release an offensive odor.
Of the many stink bug species, the most prominent ones in corn and soybean are the brown marmorated (BMSB), green (GSB), and brown (BSB) stink bugs. The feeding times within the growing season and main feeding crop can vary by species.
BSB (very common) and BMSB (seldom) may feed on corn seedlings. Injuries may include: 1) the killing of the growing point of the main plant, which usually results in tillering and/or 2) the appearance of uniform, elongated holes across the leaves that are a result of their piercing through the stem when the leaves are still inside. Scouting is important as billbug feeding can also cause the elongated holes.
Later-season corn damage occurs when BMSB and BSB pierce through the corn husk to feed on developing kernels. Ears can be deformed and fed-upon kernels can be aborted, shriveled, and lower in quality.
Stink bugs generally feed on soybean later in the season. BMSB and GSB pierce pods, destroy or severely damage the developing seed, and pods take on a flattened appearance (Figure 3). Plants that have been fed upon may stay green since pods are not being filled. This delayed maturity is called ‘stay green syndrome’ and can result in harvest issues.
Overwintering areas include wooded and grassy areas that border cultivated fields, cover crops, small grain fields, and crop residue; these areas also provide an early food source. When scouting for stink bugs in corn or soybean fields, concentrate on field edges first as initial outbreaks usually occur in border rows. If stink bug damage is noted on the field edges, the interior of the field should be examined. Note the extent of damage and count the number of stink bugs (large nymphs and adults) per plant as economic thresholds are based on these parameters. Thresholds vary by region and stink bug species present. Check with local university extension for economic threshold recommendations in your area.
Green stink bug. Acrosternum hilare Say. Field Crops IPM. Purdue University. https://extension.entm.purdue.edu/fieldcropsipm/insects/greenstinkbug.php.
Brown stink bug Euschistus spp. Field Crops IPM. Purdue University. https://extension.entm.purdue.edu/fieldcropsipm/insects/brown-stinkbug.php.
Tooker, J. 2012. Brown marmorated stink bug as a pest of corn and soybeans. Entomological Notes. The Pennsylvania State University.
Web sources verified 02/26/18. 14020508025