Assessment of a Cross-Vane Trap as a Tool for Sampling the Invasive Megacopta cribraria (Hemiptera: Plataspidae) in Soybean with Associated Evaluations of Female Reproductive Status.

Megacopta cribraria (F.) (Hemiptera: Plataspidae) is an established pest of soybean, Glycine max (L.) Merrill, in the southeastern United States. Populations of this pest in soybean are typically estimated using sweep nets, a time-consuming procedure. Cross-vane traps may provide an alternative to using sweep nets. The relationship between trap and sweep-net sampling, and the effect of distance from field edges on M. cribraria densities were studied in 2013 and 2014. Adults were detected in the traps up to 3 wk before they were present in the sweep-net samples. Adults and nymphs collected from trap and sweep-net sampling decreased from the field edge toward the field interior. Across all dates and distances, there was a strong positive association between the two sampling methods (r = 0.60), but only 36% of location analyses by week showed significant association. Females collected using both sampling methods were dissected and rated based on egg development. Female populations of all reproductive maturities dispersed into soybean, but proportions varied with sampling method. Results provide a foundation for work into understanding dispersal cues, with implications for management in soybean. Cross-vane traps may serve as an early-season tool to monitor populations, but more studies are needed before robust sampling recommendations can be defined.