Residual Efficacy of Four Organophosphate Insecticides on Concrete and Galvanized Steel Surfaces Against Three Liposcelid Psocid Species (Psocoptera: Liposcelidae) Infesting Stored Products

Abstract

Four organophosphate insecticides, azamethiphos, fenitrothion, chlorpyrifos-methyl, and pirimiphos-methyl, were tested as surface treatments on concrete (porous surface) and galvanized steel (nonporous surface) panels (0.3 by 0.3 m) against adults of three Liposcelid psocid spp.--Liposcelis bostrychophila Badonnel, Liposcelis entomophila (Enderlein), and Liposcelis paeta Pearman. Residual efficacy of these chemicals was assessed at 30 +/- 1 degrees C, 70 +/- 2% RH, and a photoperiod of 12:12 (L:D) h from 1 d after treatment (0 wk) and thereafter at weeks 1, 2, 4, 6, and 8, and then every 4 wk up to week 40. Mortality was recorded at exposure periods of 6 h and then every 24 h until end-point was achieved. L. bostrychophila was the most susceptible species to the organophosphates tested, followed by L. paeta and L. entomophila. We conclude that for long-term protection, azamethiphos is the preferred organophosphate against L. bostrychophila (up to 36 wk on steel and 24 wk on concrete storage surfaces) and L. paeta infestations only on steel surface (up to 28 wk). None of the four organophosphates tested, however, would provide long-term protection against L. paeta on concrete surface and against L. entomophila infestations on either concrete or steel storage surfaces.

Residual efficacy of cypermethrin and pirimiphos-methyl against Sitophilus granarius (L.) and Plodia interpunctella (Hübner) on concrete surface

“…metal, wood or concrete), species of stored product insects or duration of exposure (White & Leesch, 1996;Arthur, 1994Arthur, , 1997Arthur, , 1998Arthur, , 1999Collins et al, 2000;Athanassiou et al, 2013;Jankov et al, 2013;Rumbos et al, 2014). The present study therefore focused on examining the residual efficacy of EC formulations of cypermethrin (with piperonyl butoxide) and pirimiphos-methyl applied at label rates against S. granarius adults and P. interpunctella larvae on concrete surface after different periods of contact with treated surface and seven days of recovery on untreated grain.…”

Efficacy of Pyriproxyfen for Control of Stored-Product Psocids (Psocoptera) on Concrete Surfaces

“…ation when evaluating insecticides. Among the species tested here, L. paeta is considered to be tolerant to several insecticides, such as chlorpyriphos-methyl, pirimiphos-methyl, and fenitrothion, whereas L. bostrychophila is considered susceptible (Collins et al 2000, Nayak et al 2002a. In our study, there were considerably greater numbers of L. bostrychophila nymphs, in both treated and untreated dishes, in comparison with the other two species.…”

“…(Nayak et al 2005, Athanassiou et al 2009). Several organophosphate, carbamate, and pyrethroid insecticides have been evaluated for control of stored-product psocids on concrete surfaces, but they failed to provide long-term protection (Collins et al 2000;Nayak et al 2002aNayak et al ,b, 2003.…”

Psocid: A new risk for global food security and safety

“…Another problem of chemicals is that the efficacy of some insecticides varies greatly after treatment, as reported by Suchita et al (1989) and Pinto et al (1997). Collins et al (2000) tested the efficacy of azamethiphos, fenitrothion, chlorpyrifos-methyl, and pirimiphos-methyl as surface treatments on porous and nonporous surface panels against adults of three Liposcelids, L. bostrychophila, L. entomophila and L. paeta. They observed that L. bostrychophila was the most susceptible species to the organophosphates tested, followed by L. paeta and L. entomophila and that azamethiphos was the most suitable organophosphate against L. bostrychophila and L. paeta infestations for long-term protection; however, none of the four organophosphates provided long-term protection against L. paeta and L. entomophila.…”