Development of the khapra beetle, Trogoderma granarium, in the lower part of its temperature range

The lower temperature limit for breeding of the khapra beetle, Trogoderma granarium, was determined at constant temperatures in the laboratory. The length of female adult life, oviposition, egg incubation period and duration of larval plus pupal development were observed at 25, 22.5, 20 and 17.2 °C, respectively, at 70% r.h. The results show that breeding is slow at 25°, very slow at 22.5° and populations decline at 20 °C and below. Thus cooling of produce to 20 °C and retention at or below this temperature is a sound, safe, environmental friendly method for control of this pest. For newly dried malted barley, the results indicate that cooling to 25 °C would be sufficient to prevent T. granarium populations from reaching levels of economic importance.