0 Nayak, M Collins, P 2008 Pest Management Science Wiley 64: 971-976 <p><strong>BACKGROUND:</strong> The psocid Liposcelis bostrychophila Badonnel, is a widespread, significant pest of stored commodities, has developed strong resistance to phosphine, the major grain disinfestant. The aim was to develop effective fumigation protocols to control this resistant pest.</p> <p><strong>RESULTS:</strong> Time to population extinction of all life stages (TPE) in days was evaluated at a series of phosphine concentrations and temperatures at two relative humidities. Regression analysis showed that temperature, concentration and relative humidity all contributed significantly to describing TPE (P &lt; 0.001, R2 = 0.95), with temperature being the dominant variable, accounting for 74.4% of the variation. Irrespective of phosphine concentration, TPE was longer at lower temperatures and high humidity (70% RH) and shorter at higher temperatures and low humidity (55% RH). At any concentration of phosphine, a combination of higher temperature and lower humidity provides the shortest fumigation period to control resistant L. bostrychophila. For example, 19 and 11 days of fumigation are required at 15 â—¦C and 70% RH at 0.1 and 1.0mg L&minus;1 of phosphine respectively, whereas only 4 and 2 days are required at 35 â—¦C and 55% RH for the same respective concentrations.</p> <p><strong>CONCLUSIONS: </strong>The developed fumigation protocols will provide industry with flexibility in application of phosphine.</p>