Ingestion of sugary baits offered in polyacrylamide beads to the Argentine ant

CABRERA, MARIA EMILIA; HOFFMANN, BEN; JOSENS, ROXANA

Mendoza

Congreso; X Congreso Argentino de Entomología; 2018

Sociedad Entomológica Argentina

Sugar water containing toxicants can be used as an effective treatment to control the Argentine ant, Linepithema humile, however, liquid treatments are not suitable over large areas, particularly for operative and environmental reasons. What is needed is a method that supplies a liquid food source in a solid form, just like a granular bait. Polyacrylamide beads soaked in sugar solutions are one solution and have been found to be well accepted as a food source by Argentine ant. These beads have the advantage of being chemically inert, translucid, stable at different pHs and temperatures, and not represent any human or environmental risk. Here we assess the ability of ants to imbibe fluid from the beads relative to provided liquid, to evaluate the efficiency of these beads as potential baits. Ants were presented with beads soaked in 20%w/w sucrose solution (concentration recommended to use in baits for this species) or a solution of the same concentration administrated ad libitum. Crop load of ants feeding from beads (0.02µL) was 10% of the crop load obtained for the same solution ad libitum. In the light of these results, we evaluated if 20%w/w solution was the most suitable concentration of sugar within beads for feeding uptake. Following the same protocol, we quantified the same feeding variables when offered beads soaked in different sucrose concentration solutions (20, 30, 40 or 50%w/w). Crop load was greater for the diluted concentrations, reaching five times the amount ingested of the highest concentration. Our results show that Argentine ant can consume liquid from the beads, although not as much as from sugar-water provided in a liquid form. Therefore the beads show great potential for use as a control technique. The use of lower sugar concentrations maximized the volume of liquid consumed. Therefore, it is expected to be more efficient to use beads soaked in sucrose solutions in the range of 20 to 30%. Another crucial aspect to analyze would be the lifespan of the beads once they?re taken out of the solution.