Evaluation of the ability of subterranean termites (Isoptera: Rhinotermitidae) to differentiate between termiticide treated and untreated soils in laboratory tests

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: p.33-36.Issued also on microfiche from Lange Micrographics.The effect of untreated gaps within the chemical barrier was determined for permethrin, cypermethrin, fenvalerate, chlorpyrifos and imadacloprid at the termiticide concentrations of 1000 ppm, 500 ppm, and 100 ppm. Minimum size of the untreated gap within the termiticide treated soil, and the minimum time required for the termites to reach the food source through these untreated gaps were determined for each of the five termiticides at three concentrations. Field condition was simulated in the laboratory using experiment chambers made of Plexiglas 0 (30 x 15 x 15 cm) filled with layers of untreated, treated, and untreated soil. The broken barrier was created by inserting glass tubes containing untreated soil in the center of the chamber. Subterranean termites (Reliculitermes spp.) were introduced at the top layer of untreated soil. The system was observed for seven days or until the termites were seen at the food source which was at the bottom of the experiment chamber. With pyrethroids (permethrin, cypermethrin and fenvalerate), termites reached the food source at all three concentrations, though the size of the gap and time for tunneling was different for each pesticide. Ninety percent of the termites were alive on the seventh day of the tests, In the organophosphate termiticide (chloropyrifos), termites were unable to make use of the untreated gaps within 7 days, and no termites were found to be alive after 7 days of testing. In the tests with chloronicotinyl (imidacloprid), termites were unable to locate the untreated gaps within seven days. However, only IO% of the termites were alive by the seventh day at the concentration of I 00 ppm