Location: Stored Product Insect Research Unit
Title: Residual efficacy of chlorfenapyr for control of stored-product psocids (Psocoptera) Authors
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 23, 2013
Publication Date: N/A
Interpretive Summary: Psocids, which are also known as booklice, are becoming more important as pests of stored bulk grains and processed foods. Insecticides applied to flooring surfaces are often not as effective on psocids as they are on beetles. We conducted studies by exposing three different psocid species on concrete treated with different rates of the insecticide Phantom. Although the three species varied in susceptibility to Phantom, mortality increased with application rate. At the highest rates, mortality was 95 to 100% when the psocids were exposed for three days on the treated concrete. Also, residual control lasted for at least three weeks. Results show Phantom could potentially be used in insect pest management plans for psocids.
Technical Abstract: The residual effect of chlorfenapyr (Phantom®) was evaluated for residual control of three stored-product psocid species: Liposcelis bostrychophila Badonnel, Liposcelis entomophila (Enderlein), and Liposcelis paeta Pearman. Chlorfenapyr was applied to individual arenas with a concrete surface at rates of 0, 2.8, 13.8, 20.6, 27.5, 55, and 110 mg AI/m2. Adults were exposed on the treated arenas and mortality assessed after 1, 2, and 3 d. The procedures were repeated weekly on the same treated arenas for three weeks to assess residual efficacy. At each week, mortality of all species was low after 1 d of exposure, but notably increased after 2 or 3 d. L. entomophila was the most susceptible species, with 99-100% mortality at rates of 13.8 mg/m2 or higher. Similarly, mortality of L. paeta after 3 d of exposure at the same concentration ranged from 92 to 100%. L. bostrychophila was the least susceptible species, with mortality during the third week after the application at <60 % at an application rate of 27.5 mg/m2. However, even for this species, mortality after 3 weeks was 90% or higher at rates >27.5 mg/m2. Complete mortality of all species occurred after 3 d exposure at the highest dose rate tested of 110 mg/m2. Thus, our results show that chlorfenapyr is effective against major psocid species at the application rates evaluated in this study.