Dispersion of Piezodorus guildinii Adults (Hemiptera: Pentatomidae) between Soybean and Alfalfa Crops
We studied the dispersion of Piezodorus guildinii adults between adjacent soybean and alfalfa fields. From the beginning of soybean pod formation (R3) until fully developed seed (R6), marker proteins (alfalfa = bovine casein, soybean = soy protein) were applied weekly in each crop. In both crops, two transects were established separated by 12 m between each other, with seven sampling points established at every 7.5 m. Stink bugs were collected using a sweep net in the 48 hours after each application of protein markers. Immunoassays were performed using ELISA. In total, 464 adults of P. guildinii were collected, 166 from soybean and 298 from alfalfa. Seventy two point four per cent were positive for at least one of the proteins. The marking efficiency was 53.6 and 89.1 % for bovine casein and soy protein, respectively. Stink bugs moved unidirectionally and bidirectionally between crops. Predominant unidirectional movements were from soybean, suggesting that uncut alfalfa near the soybean crop during the reproductive period of soybean reduces the colonization of P. guildinii in the latter crop. Dispersion distances ranged from 2.5 to 47.5 m, with an average of 17.4 m. The results indicate that the immunomarking technique of P. guildinii adults may be used to learn how populations use adjacent patches of habitat and to design farmscape pest management strategies.