Although the toxic
effects of ozone on some insect pests of stored products are already known, there is little information
about their effects inside the grain column. This study aimed to evaluate Rhyzopertha dominica (Fabr.)
(Coleoptera: Bostrichidae) control by ozone gas in wheat grains. Ozone was applied at a concentration
of 1.61 mg L
-1
and flow rate of 2.0 L min
-1
in wheat grains. Inside the grain column, insects were placed
in plastic cages distributed at three different points: on the plenum (basis), middle part and surface. The
toxicity results indicated that the periods of ozone exposure that were necessary to cause mortalities of
50 and 95% in adult R. dominica ranged from 8.69 to 13.08 h and from 11.28 to 18.11 h, respectively.
Shorter lethal times were observed when the insects were distributed on the basis of the grain column.
A decreased instantaneous growth rate of R. dominica was observed with an increased exposure
period. There was a significant correlation between the instantaneous growth rate and the physical and
physiological characteristics of wheat grain.