Evaluation of non‐target bait attraction by pollinating insects when using water‐storing granules for invasive ant management

BACKGROUND Water‐storing granules (WSGs) such as hydrogels are a promising management tool for invasive pest ants because they present attractive sugar‐water bait in easily dispersible granular form. However, the attraction of pollinators and other non‐target insects to such granules is a concern. We evaluated this non‐target risk through staged video observations of baits and field broadcast of protein immunomarked baits using three types of WSG. RESULTS Granules staged on the ground attracted few insects from common pollinating groups, which together comprised < 8% of non‐ant visitors. However, baits placed near flowers elicited 3.8 times higher visitation rates with > 90% being common pollinators. Broadcast plots that tested small‐scale bait application scenarios revealed low rates of insect interaction with WSGs , likely because most granules fell to the ground. Less than 10% of pollinators and approximately 10% of all flying insects captured were marked, although several taxa had substantially higher rates of marking. CONCLUSION Ant management using hydrogels or other WSG baits should pose relatively low risk to pollinating insects in the shrubland ecosystems studied. However, higher mortality among some non‐target species from direct bait consumption may occur, species‐specific effects may be challenging to predict, and indirect risks from pesticide residues should also be considered.