Feeding Inhibition and Mortality inReticulitermes flavipes(Isoptera: Rhinotermitidae) After Exposure to Imidacloprid-Treated Soils

Abstract

Feeding inhibition and mortality of Reticulitermes flavipes (Kollar) exposed to sand, sandy loam, loam, and silty clay loam soils treated with several concentrations of imidacloprid were studied using bioassay techniques under laboratory conditions. Termite workers stopped feeding after exposure to treated soils. Differences in feeding reduction varied among the soil types. Based on the magnitude of the F-statistics, the effect of imidacloprid on the reduction of termite feeding was greatest in sand followed by sandy loam, loam, and silty clay loam soils. Soil properties such as organic matter content, silt and clay proportions, pH, and cation exchange capacity were suggested to affect the bioavailability of imidacloprid. Similar soil effects on mortality were observed in termites continuously exposed to treated soil for 21 d. In three of four soils tested, susceptibility to imidacloprid was not affected by the source of the termites tested.

Factors Affecting Performance of Soil Termiticides

“…Saran and Kamble (2008) reported an inverse relationship between the initial concentrations of bifenthrin, fipronil, and imidacloprid and their LT50 and LT90 values against R. flavipes. Greater bioavailability at higher concentrations may explain similar trends reported by Smith and Rust (1992), Forschler and Townsend (1996), and Ramakrishnan et al (2000). At low rates, fipronil has low soil affinity, but adsorption increases with concentration (Bobé et al, 1997).…”

Toxicity of Acetamiprid to Workers of <i>Reticulitermes flaviceps</i> (Isoptera: Rhinotermitidae), <i>Coptotermes formosanus</i> (Isoptera: Rhinotermitidae) and <i>Odontotermes formosanus</i> (Isoptera: Termitidae)

“…[19][20][21][22] Besides being directly lethal to termites, imidacloprid has sublethal effects on the behavior 23) and feeding 24) of termites. Meanwhile, imidacloprid could be transferred among individuals of C. formosanus.…”

Effect of Imidacloprid Tree Treatments on the Occurrence of Formosan Subterranean Termites, <I>Coptotermes formosanus</I> Shiraki (Isoptera: Rhinotermitidae), in Independent Monitors

“…(Thorne and Breisch 2001, Boucias et al 1996, Ramakrishnan et al 2000. Combining all after treatment collection dates, the Dorm sector had signiÞcantly fewer monitors occupied by C. formosanus (9.0 Ϯ 14.2%) than any other sector (Ͼ27%) over the 17-mo sampling regime (Table 1; Fig.…”

“…Thus, repopulation of the Dorm sector probably occurred only from the North or from galleries bridging a sizable distance under the roads or parking lot. The different response of the termite population in the Dorm sector could also reßect a difference in insecticide susceptibility (Thorne and Breisch 2001, Ramakrishnan et al 2000, Osbrink et al 2001, or native entomopathogens (Boucias et al 1996, Ramakrishnan et al 1999.…”