Eradication of the Stored-Product Mite, Tyrophagus putrescentiae (Shrank) in Flour and Wheat Bran Using Microwave Energy

Abstract

Mortality of adults and larvae of the stored product mite, Tyrophagus putrescentiae infested flour or wheat bran exposed to microwave radiation (2450 MHZ) was evaluated as a function of exposure time and power. Mortality experiments were conducted at exposure times 60-300 sec at power level of 110 W and from 10 to 90 sec at 330 and 550 W. Adult and larva mortalities were higher in flour with 12.5% moisture content (m.c.) than in wheat bran with 8.5 % m.c. The minimum average temperature (27.8 oC) was recorded in wheat bran at 330 W for 10 sec, whereas the maximum average was 60.5oC in flour at 550 W for 90 sec. Complete mortality of larvae and adults of T. putrescentiae was obtained at 45 and 46.6 oC, respectively. T. putrescentiae larvae presented a mortality rate higher than adults when exposed to the same Mw energy radiation.