Do physiological host ranges of Drosophila suzukii parasitoids reflect their ecological host ranges in an adventive landscape?

In importation biological control, natural enemies (aka biocontrol agents) are released into the invaded range of a target pest species to regulate pest populations. Host specificity in biocontrol agents is central to work investigating suitability of agent release in novel environments. Parasitoids are common biocontrol agents as they are often highly host specific. Physiological host range testing identifies which non-target organisms can be attacked by likely biocontrol agents and provides valuable information for evaluating ecological risks associated with agent release. Physiological host range testing oversimplifies natural processes which limit non-target host availability and thus often overestimates non-target attack in nature. Integrating ecological criteria into physiological host range testing improves the relevance of the findings for implementation in integrated pest management. Two parasitoids (Hymenoptera: Figitidae) with differing specificity in their physiological host range have been identified as promising candidates for the control of the small fruit pest Drosophila suzukii Matsumura (Diptera: Drosophilidae). Adventive populations of both parasitoids have recently been detected in south-western British Columbia, Canada. The adventive presence of these parasitoids offers a unique opportunity to evaluate the ecological host range of the parasitoids before their possible continent-wide release. I integrate host ecology into host range experimentation along a ‘sliding scale’ from classic physiological host range testing considerations towards ecological host range testing exposing non-target drosophilids to the adventive parasitoids in the field. I report preliminary results from this experimentation to enable more effective pest management of D. suzukii and improve agro-ecosystem sustainability in the pest’s invaded range.