LAUSR

BACKGROUND Aerial treatments for invasive species management are now common, but we are unaware of any work published in the scientific literature quantifying how the interplay of numerous factors affects flight times and therefore operational costs. Here we analyse aerial treatment data collected from two ant eradication programs, quantifying how the relationships between flight time and area are influenced by numerous aircraft/delivery system/bait/flight speed combinations. RESULTS For bait dispersal by helicopters, and when swath widths are equivalent, using side-mounted Isolair was significantly more efficient than simultaneous use of two underslung buckets, and using two buckets was slightly but not significantly more efficient than using just one bucket. In this scenario delivery by Isolair was, on average, 39.8% and 31.5% more efficient than the use of either one or two buckets respectively. But when the swath width used with the Isolair was halved to 10 m and the flight speed increased slightly, the flight time was significantly greater compared to both other configurations. For bait dispersed by drone, flights conducted using an upgraded flight management system (FMS) and higher flight speed but smaller swath width were significantly more efficient than those using the older FMS and lower flight speed. Over 10 ha and 50 ha the helicopter was 2.87 and 4.82 times more time efficient than the drone. CONCLUSION We highly encourage practitioners to publish data of their aerial treatments, as well as to try new methods, to enable an acceleration of improving efficiencies and reducing costs of aerial treatments. This article is protected by copyright. All rights reserved.