A current focus of our laboratory is the use of insect and other arthropod sentinels for the collection and delivery of environmental pathogens of human concern. On the basis of results from field experiments, we hypothesize that arthropods vary in their recovery efficiency with respect to mode of feeding and agent uptake. To test these hypotheses, representative arthropods were fed or exposed to B. atrophaeus (=B. subtilis var. niger), a standard non-pathogenic surrogate for B. anthracis. Experimental and control arthropods were assayed over time using microbiological culturing on TSA and by PCR using B. atrophaeus-specific primers developed in our laboratory. Results demonstrate that arthropods vary in their utility as short and long term sentinels. These differences can be exploited in the design of monitoring programs for bio/agroterrorism and emerging plant and animal pathogens.