D. K. KUZMANOV, N. D. DIMITROV, N. P. GINOV and I. G. YANCHEV
University of Food Technologies, BG - 4002 Plovdiv, Bulgaria
KUZMANOV, D. K., N. D. DIMITROV, N. P. GINOV and I. G. YANCHEV, 2008. A heated trap for detecting insect infestation in stored grain at low temperatures. Bulg. J. Agric. Sci., 14: 528-534
In detecting insects and monitoring of infestation in cooled down grain storage, trap sensitivity has been decreased. In order to avoid this problem a trap with a built-in heater has been developed. The heater increases the temperature in the trap up to the optimum one for insects trapping. The appropriate heater power (2.1 W) to keep up the temperature of the trap at 33°C has been determined at laboratory conditions. An outer controller has been used to keep up a constant temperature. Two couples of traps have been used - heated traps and unheated traps, which have been investigated in a flat storehouse and in a metal silo cell filled with wheat with a temperature of 8 - 19 °C. It has been established that the detection frequency of rice weevil Sitophilus oryzae (L) and sawtoothed grain beetle Oryzaephilus surinamensis (L.) by using the heated trap has increased by 30 and 80 %, respectively. The number of insects of O. surinamensis trapped by using the heated trap has been significantly higher by 3.2 times while the difference between the numbers of S. oryzae insects trapped by using both traps has been insignificant. As regards the method of taking samples, the frequency of insect detection by using heated trap has been by 60% greater. Thanks to the increased sensitivity of the heated trap it is now possible not only to detect insects in stored grain during its cooling down but also to follow the insect infestation variation.