noviflumuron and fipronil

This study evaluated the impact of a non-repellent liquid termiticide (fipronil) and a chitin synthesis inhibitor (CSI) termite bait (noviflumuron) on whole colonies of Coptotermes gestroi (Wasmann) (Blattodea: Isoptera: Rhinotermitidae) in laboratory conditions, over a 12-m foraging distance. The protocol simulated the implementation of remedial treatment of an infested structure, where the colony has multiple access routes, and where only a portion of the population was directly exposed to the treatment. Within 2 wk after the implementation of fipronil, all termites within 1.5 m away from the treatment died. The accumulation of cadavers near the treated area resulted in secondary repellency and the colonies avoided the treated area for the remaining 10 wk of the experiment, using alternative foraging galleries. At the end of the 12 wk, colonies exposed to fipronil did not have any difference in population size compared with control colonies. Comparatively, colonies exposed to noviflumuron had no change in foraging activity for the first ≈40 d, but then termites progressively ceased their activity throughout their foraging territory. By 12 wk, noviflumuron-exposed colonies were near-elimination, with only a few workers, soldiers remaining, and all colonies were eliminated by 95 d. This study shows that subterranean termite colonies with access to CSI baits are inevitably eliminated, regardless of the position of the bait, while colonies exposed to fipronil are only locally excluded from the area near the treatment, but may maintain their foraging activity in untreated areas, and retain their potential risk for structural damage in the long term.

Topics: Animals; Benzamides; Hydrocarbons, Fluorinated; Insect Control; Insecticides; Isoptera; Pyrazoles

The insecticidal activity of a cockroach gel bait containing a chitin synthesis inhibitor, noviflumuron, was evaluated using laboratory and field strains of the German cockroach, Blattella germanica (L.). Noviflumuron gel bait (0.01-5 mg g(-1)) caused > or = 90% nymphal mortality to laboratory and field strains of B. germanica in choice tests after 11 and 19 days of continuous exposure respectively. In 1 m x 1 m bioassay arenas, laboratory strain B. germanica population levels exposed to 5 mg g(-1) noviflumuron bait or 0.1 mg g(-1) fipronil gel bait were significantly lower than untreated population levels after 3 weeks and 1 week of exposure respectively. Various noviflumuron bait exposure periods (2, 4 and 7 weeks) caused similar population reductions, with a mean of 99.3 (+/- 0.3)% at 7 weeks. Fipronil gel bait caused 100% population reduction at 2 weeks post-exposure. The control population increased 89.0% at 7 weeks. In a simulated kitchen experiment with mixed stage laboratory populations, cockroach trap catches decreased 96.8 (+/- 2.0)% at 8 weeks in the 0.5 mg g(-1) noviflumuron bait treatment. The trap catches in the control increased 506.5 (+/- 493.7)% during the same period. Trap catch reduction by 0.1 mg g(-1) fipronil gel bait reached 100% at 4 weeks. Noviflumuron bait caused significantly lower nymph/total ratios to B. germanica populations in bioassay arenas from 2 weeks after exposure, demonstrating its effectiveness as a control agent for B. germanica with a pattern of activity similar to that expected from a chitin synthesis inhibitor.

Topics: Animals; Benzamides; Blattellidae; Gels; Hydrocarbons, Fluorinated; Insecticides; Pyrazoles; Toxicity Tests

Distance effects of three treatments, noviflumuron, fipronil, and thiamethoxam, against laboratory populations of the Formosan subterranean termite, Coptotermesformosanus Shiraki, were tested in extended foraging arenas with foraging distances of 50 m. The results showed that during the 10-wk test period, all termites were killed by noviflumuron baits, whereas the nonrepellent termiticides fipronil and thiamethoxam divided the laboratory populations into two groups after causing 25-35% worker mortality. The horizontal transfer of lethal effects of fipronil was < or = 5 m. For thiamethoxam, the distance of transfer was substantially shorter. Because of their dose-dependent lethal time, the nonrepellent termiticides did not fulfill the requirements of a liquid bait model.

Topics: Animals; Benzamides; Feeding Behavior; Hydrocarbons, Fluorinated; Insect Control; Insect Repellents; Insecticides; Isoptera; Neonicotinoids; Nitro Compounds; Oxazines; Pyrazoles; Thiamethoxam; Thiazoles