Combined effect of ozone mixed with carbon dioxide on the mortality of five stored-product insects

Abstract

A study to determine the effect of ozone mixed with carbon dioxide on controlling stored-grain insects was conducted in the storehouse. Adults of Sitophilus oryzae (L.), Tribolium castaneum (Herbst), Rhyzopertha dominica(F.), Oryzephilus surinamensis(L.) and 3 th larvae of Plodia interpunctella(Hubner) were exposed to the mixture of ozone and carbon dioxide. After exposure periods of 24 h, the insects were transferred to clean jars containing food and held at 27±2 o C and 65 ±5% R.H. Experiments were performed in different heights (30, 40, 50 and 100 cm) and nutrition materials (date, wheat and rice), in penetration tests and empty-space tests. In empty-space trials, the highest mortality was for P. interpunctella. In penetration tests, treatment with high-pressure ozone and carbon dioxide under different height and foodstuff may result in different rates of mortality. The mixture of ozone and carbon dioxide in the interaction between height and diet (heigh×diet) are not significant for the S. oryzae, T. castaneum, R. dominicaand P. interpunctellabut for O. surinamensis is significant. The influence of ozone gas and carbon dioxide in the date is more than rice and wheat. The mixture of ozone with carbon dioxide can be as suitable fumigant for decreasing phosphine and methyl bromide under ambient storage conditions in penetration and empty-space fumigations.