Field Evaluations of a Novel Biodegradable Microfibrillated Cellulose Hydrogel Bait Targeting the Invasive White-Footed Ant, Technomyrmex brunneus

Abstract

The development of more effective control methods for invasive alien ants is crucial, given the extensive damage these ants cause. In recent years, hydrogel baits—superabsorbent polymers containing a water solution of insecticides and ingredients that promote or attract ant feeding—have been developed and used to control invasive ants. More recently, biodegradable hydrogel baits have been developed and tested for efficacy. We have developed a new type of biodegradable hydrogel bait in which microfibrillated cellulose (MFC) derived from plant cellulose acts as a gelling agent. A cafeteria experiment, including the conventionally used sodium polyacrylate hydrogel bait and the newly developed biodegradable MFC hydrogel baits with various chemical properties, showed that both types of hydrogel bait were highly effective in recruiting workers of the invasive white-footed ant, Technomyrmex brunneus, to the same degree. Among the MFC hydrogel baits tested, the more effective substrates were selected, and their control efficacy was confirmed in field experiments; baiting at 2-week intervals reduced the population of T. brunneus by more than 90%. The biodegradable MFC hydrogel baits have substantial potential to effectively control invasive ants, with a smaller environmental impact than the conventional sodium polyacrylate hydrogel baits.