Range of detection and naturalistic search performance for spotted lanternfly (Lycorma delicatula) egg masses

The spotted lanternfly (Lycorma delicatula, SLF) poses a significant threat to U.S. agriculture, particularly vineyards, hops, and ornamental plants. Early detection of SLF egg masses is critical for limiting spread, yet current strategies are constrained by the availability of trained personnel and are extremely time-consuming. Detection dogs have shown strong potential for locating SLF egg masses with high accuracy, and training can be completed using devitalized samples, eliminating the risk of accidental release of this invasive insect. In a prior study, we demonstrated that participatory science teams, volunteer handlers with scent detection experience, could successfully train their companion dogs to detect devitalized SLF egg masses. This follow-up study evaluated whether selected teams from the original cohorts could perform under more complex, operationally relevant conditions. Specifically, we assessed detection accuracy and field performance across two experimental settings: (1) a range of detection (RoD) tests to estimate reliable detection distance, and (2) a naturalistic field search in previously unsurveyed areas with unknown target presence, allowing comparison with human surveyors. In the RoD trials, dogs demonstrated the highest sensitivity (0.52) at 0-5 m, declining to 0.06 at 10-15 m, with overall precision ranging from 0.61 to 0.92 across distance bands where detections occurred. Several dogs also successfully generalized from devitalized training aids to naturally occurring, previously undetected SLF egg masses. In naturalistic searches, canine teams located more confirmed SLF egg mass sites than trained human searchers, highlighting their ability to detect cryptic targets under real-world conditions. Although not all canine alerts could be confirmed, the results indicate that trained community detection teams can effectively complement or enhance traditional survey methods. Overall, these findings support the operational feasibility of participatory science detection teams for SLF surveillance. Despite range limitations, trained community dog-handler teams can successfully detect SLF egg masses and, in some cases, outperform human searchers, offering a scalable, biosecure, and cost-effective approach to invasive species detection.