Computer modelling of insect-induced hot spots in stored wheat

Mani, S., Muir, W.E., Jayas, D.S. and White, N.D.G. 2001. Computer modelling of insect-induced hot spots in stored wheat. Canadian Biosystems Engineering/Le génie des biosystèmes au Canada 43:4.74.14. A computer model of insect-induced hot spots in stored wheat was developed by combining four submodels: (1) a three-dimensional, finite element model of heat transfer, (2) a population dynamics model of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), (3) a model of the heat production by C. ferrugineus, and (4) a model of the movement of C. ferrugineus. Under Winnipeg, Manitoba weather conditions, a minimum of 1300 adult C. ferrugineus introduced in the early fall at the top-centre of an unventilated 6-m diameter wheat bulk initially at 30LC caused hot spots in late winter. At an initial grain temperature of 25LC and 6000 adults introduced at the top-centre of the wheat bulk, no hot spot developed. In large diameter bins (6 to 12 m), hot spots occurred at the end of the fall and the centre temperatures reached a peak of 40LC. Due to the steep temperature gradient towards the north side of the bulk, insects initially introduced in the north side moved to the centre and caused hot spots earlier than when insects were initially introduced in the south side of the bulk.