Inhibition of egg development by phosphine in the cosmopolitan pest of stored products Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Abstract

Phosphine-induced delay in development of eggs was investigated as a mechanism of resistance to this fumigant in Liposcelis bostrychophila Badonnel. One-day-old eggs of a susceptible and a strongly resistant strain of L bostrychophila were exposed to a range of phosphine concentrations for 6days at 30 (+/- 1) degrees C and 70 (+/- 2)% RH. Delay in mean hatching period occurred in both susceptible and resistant eggs, although it was more pronounced in the latter. A maximum delay of 2.65 days was recorded for eggs of the susceptible strain at 0.01 mg litre(-1) (the highest concentration at which eggs survived) and 13.39 days for the resistant strain at 1 mg litre(-1) (the highest concentration tested). Delay in egg development time was positively correlated with increasing phosphine concentration. Our results reveal that the most successful strategy to control resistant L bostrychophila is to apply relatively low concentrations of phosphine for extended exposure times (eg 0.05 mg litre(-1) for 16 days) that allow all eggs to hatch to the much less tolerant nymph stage.

Population Growth and Development of the Psocid Lepinotus reticulatus at Constant Temperatures and Relative Humidities

“…The rise of psocids to prominence can be attributed to their varied response to management tactics that have been developed for beetle pests, e.g., some psocid species are resistant to residual insecticides and the fumigant phosphine, whereas others are not (Nayak et al 1998(Nayak et al , 2002a(Nayak et al , 2002b(Nayak et al , 2003Nayak 2006). In addition, markets increasingly view psocids as contaminants (Nayak 2006).…”

Psocid: A new risk for global food security and safety

“…Psocids found in warehouses, granaries and cereal stores may be divided into five groups, Banded psocids, Cereal psocids, Grain psocids, Cosmopolitan grain psocids and Larger pale trogiid psocids. L. bostrychophila have been termed as Cosmopolitan Psocids (Nayak et al, 2003). In some literature they have also been named as Banded Psocids.…”

Molecular characterization of two novel deltamethrin‐inducible P450 genes from Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

“…In addition, the rapid development of resistance to physical and chemical treatments by the psocids has been reported (Wang and Zhao, 2003). Moreover, almost all currently registered grain protectants that target these pests, such as deltamethrin, permethrin, and carbaryl, fail to control the psocids (Nayak and Daglish, 2007), which elevated their pest status enormously and put them alongside the major beetle pests (Nayak et al, 2003).…”