Tracking within-field movement of soybean stem borer, Dectes texanus, adults using protein markers

Aerial applications of insecticides that target adult soybean stem borers, Dectes texanus Leconte (Coleoptera: Cerambycidae), in Kansas soybean (Glycine max L.) can reduce populations in the field. However, several applications are needed due to recolonization and adult immigration into a field. Understanding adult movement and colonization patterns, in general, can potentially aid in the development of site-specific pest management strategies to mitigate loss due to D. texanus. The objective of this study was to examine the movement of D. texanus in soybean production fields by using protein markers. Six D. texanus infested soybean production fields in Kansas were sampled from June to August in 2012 and 2013. Two protein markers (bovine casein and chicken egg albumin) were sprayed along two edges (4 x 400-500 m) within each soybean field (target field) every 10 d during D. texanus adult activity. Fields were grid sampled and we sweep netted (80 sweeps per point) for adults at all waypoints; size of a soybean field determined the number of waypoints. Specimens collected were analyzed for presence of protein using enzyme-linked immunosorbant assay (ELISA). We hypothesized that adult D. texanus will aggregate along field edges during early colonization, dispersing throughout the field towards the end of adult activity and composition of field edge would influence patterns observed within a field; densities will be concentrated in spray areas located next to previous years soybean crops and alternative plant hosts. Preliminary results suggest that adult colonization patterns vary between fields and through time.