An immunological approach to assess trophic interactions: Evaluating the efficacy of a hemlock woolly adelgid-specific monoclonal antibody

Monoclonal antibodies are rapidly becoming useful tools in quantifying predator-prey interactions. Using an antibody in an ELISA assay, mass-screening of various predator and non-target species is possible. Currently, a species-specific monoclonal antibody for hemlock woolly adelgid Adelges tsugae (HWA) is being developed. In preliminary trials the HWA-specific antibody has shown little to no cross-reactivity with various congeners (A. piceae, the balsam woolly adelgid), order members (Aphididae or other Adelgidae) and non-related targets (Coccinellidae, Araneae, Diptera, etc.). Additional forest arthropods from hemlock habitats are currently being screened for cross-reactivity. Since protein digestion in predator guts varies, an efficacy test of the antibody is being conducted to determine how long following consumption the antibody can detect adelgid protein. Feeding trials with Sasajiscymnus tsugae are under way. My first trial evaluates S. tsugae fed on HWA; my second trial will evaluate S. tsugae fed the closely related pine bark adelgid, Pineus strobi. Beetles will be starved for three days and then allowed to feed on HWA for 1hr. Post-consumption, beetles will be frozen at 0, 2, 4, 6, 8, 12, 18, 36, 48hr intervals, homogenized and the antibody will be evaluated in an ELISA.