Edge effects on blue cross vane traps

Blue cross vane traps (BCVT) are effective at trapping non-Apis bees, even in the presence of floral competition. Non-crop habitats, including native prairie, serve as reservoirs for bees. Native prairies are being utilized to produce a hay crop for livestock feed. The effect of this use on bees is not clear. Before conducting a large-scale study, we wanted to determine if our plot size would be large enough to detect differences between cut and uncut treatments. Two prairie hay fields were selected. Each site is hayed once a year and had a tree row on one edge. Approximately a three-acre portion was left uncut for the duration of the test. One BCVT was placed in the center of each uncut portion. An additional transect of BCVTs was laid out perpendicular to the tree row border in the cut portion of the prairie hay field. Trap distances from the tree row were 0, 5, 10, 20, and 40 meters. The 40m trap was used to compare uncut to cut hay trap catches. A total of 2701 bees belonging to 16 genera were collected over 12 trapping days. There was no significant difference (P<0.05) between the cut and uncut hay in the number of bees trapped (P=0.06). This difference may be attributed to the small sample size (n=12). Also there was no significant difference (P<0.05) between the transect distances in the number of bees trapped. A non-metric multidimensional scaling analysis demonstrated that bee communities were very similar among all trap placements.