Comparison of sampling techiques for phytophagous species of stink bugs (Heteroptera: Pentatomidae) in cotton

Different methods for sampling phytophagous species of stink bugs in cotton, Gossypium hirsutum (L.), were compared. Fields were sampled weekly beginning at anthesis using a sweep net (38.1 cm) and ground cloth (0.91 x 0.91 m). Bolls were examined for symptoms of feeding injury to indirectly measure the presence of bugs. All methods were timed and compared for efficiency and precision. The ground cloth was the fastest method (36 sec/sample ± 17 SEM) of sampling compared with sweep net (74 sec/sample ± 17 SEM) and boll examination (543 sec/sample ± 17 SEM). More nymphs were detected with the ground cloth (0.52 ± 0.22 SEM) than with the sweep net (0.27 ± 0.22 SEM), and more adults were detected with the sweep net (0.60 ± 0.07 SEM) than with the ground cloth (0.32 ± 0.07 SEM); however, the methods were not significantly different when total bugs were analyzed (F=0.15; df=1, 17.1; P=0.7057). Although sampling for internal injury to bolls was the most time-intensive method, it was at least twice as sensitive in detecting the presence of bugs (80.6%) as the ground cloth (29.1%) or sweep net methods (37.4%).