Impact of Growth Stage and Sample Time on Phytophagous Stink Bug (Hemiptera: Pentatomidae) Scouting Efficacy in Midsouthern U.S. Soybean

Phytophagous stink bugs are a significant arthropod threat of soybeans in the mid-southern United States. Several species occur in this region, with the brown stink bug, Euschistus servus (Say), the green stink bug, Chinavia hilaris (Say), the southern green stink bug, Nezara viridula (L.), and the redbanded stink bug, Piezodorus guildinii (Westwood), being the most economically important. These pests are typically detected during the reproductive stages of soybean, when pod formation and filling occur. Much is known about stink bug occurrence and subsequent impacts in soybeans in this region; however, little is known regarding the environmental factors that can influence stink bug behavior within soybean canopies. Studies were conducted across the mid-southern United States to determine how sampling time affects stink bug detection utilizing 2 common sampling tools—sweep nets and drop cloths. Regardless of the sampling method utilized, adult, nymph, and total stink bug detection was lowest during the earlier reproductive growth stages (R5 & R6) and peaked during the later stages (R6.5 & R7). Sample time played a significant role when sweep nets were utilized to determine stink bug densities, with significantly more stink bug nymphs detected during the cooler, morning hours. Drop cloths tended to be much more effective in detecting stink bugs of all life stages, regardless of sample time. These data indicate that special attention should be given to both sample time and method when nymph stink bug densities increase during the later soybean growth stages to prevent excess seed damage or yield loss.