Fipronil

Hydrogel ant bait for all work was prepared by placing hydrogels in 30% sugar‐water solutions containing 0.006 mL L^–1 fipronil [sourced from Termidor® (BASF, Florham Park, NJ, USA) containing 100 g L^–1 fipronil] (i.e. a mixture of water:sugar:Termidor® of 350:150:0.003), and allowing 24 h for the solution to be absorbed. Sugar used was standard 1A sugar from the New Zealand Sugar Co. Ltd, Aukland, New Zealand), and the hydrogels were Water$ave Floragel® from Polymer Innovations Pty Ltd, Singleton, NSA, Australia). The bait was prepared 24 h before use in all instances.
The bait dispersal mechanism was a 300‐mm granular spreading disk, hereafter referred to as the spinner, spinning at 720 rpm which propelled the hydrogels out with centrifugal force as they flowed down from a holding container, in the same manner as any manual fertilizer spreader.

The following three insecticidal formulations were used for the experiment: i. Movento OD, which is an oil-dispersion containing 15.78% w/v spirotetramat as a.i. (provided by Bayer Hellas, Greece), ii. Termidor SC, which is a suspension concentrate that contains 9.1% w/w fipronil as a.i. (provided by BASF Hellas, Greece), and iii. Confidor SL with 20% w/v imidacloprid as a.i. (provided by Bayer Hellas, Greece). Vertimec EC, an emulsifiable concentrate that contains 1.8% w/v abamectin as a.i. (provided by Syngenta, Greece), was used as positive control, since it was documented as an effective insecticide against X. chinensis using the endotherapy method [15 (link)].

Insecticides used were indoxacarb (15% a.i., DuPont, Wilmington, DE) and fipronil (9.1% a.i., BASF Corp., Research Triangle Park, NC). Calculated amounts of an indoxacarb solution (ca. 1.0 mL) were applied uniformly to Whatman No. 1 filter paper (Whatman International Ltd., Maidstone, UK) placed in glass Petri dishes to obtain 50, 75, and 100 ppm indoxacarb-treated filter paper. The procedure was repeated for fipronil to obtain 0.5, 1, and 5 ppm fipronil-treated filter paper. The same stock insecticide solutions were used to treat the filter paper used against both termite species at all temperatures. Filter paper treated with distilled water was used as control treatment. Treated papers were air-dried in a laboratory hood for 24 h at about 23 °C and moistened with 0.4 mL of distilled water immediately before the introduction of termites.