Efficacy of Ozone Fumigation Against the Major Grain Pests in Stored Wheat

Abstract

Field experiments were conducted in steel bins containing 13,600 kg of hard red winter wheat, Triiticum aestivum L. One bin was treated with ozone and the second bin served as a control. Stored grain insects were placed in bins for 1-, 2-, 3-, and 4-d exposure periods in sampling tubes to test ozone concentrations of 0, 25, 50, and 70 parts per million by volume (ppmv). Ozone treatments on eggs and larvae of Plodia interpunctella (Hübner) were not effective, but pupae were more susceptible. Sitophilus oryzae (L.) adults were the most susceptible species with 100% mortality reached after 2 d in all ozone treatments. However, some progeny were produced at all concentrations and exposure periods. Tribolium castaneum (Herbst) adults had 100% mortality only after 4 d at 50 or 70 ppmv. No T. castaneum progeny were produced after 2-4 d at 70 ppmv. For Rhyzopertha dominica (F.), Cryptolestes ferrugineus (Stephens), and Oryzaephilus surinamensis (L.), 100% mortality was never achieved and progeny were produced at all ozone concentrations. Laboratory experiments, testing the effectiveness of ozone in controlling psocids, were conducted in two polyvinyl chloride cylinders each containing 55 kg of hard red winter wheat. Ozone treatment at a concentration of 70 ppmv was highly effective against adult female Liposcelis bostrychophila Badonnel and Liposcelis paeta Pearman after only 1 d of exposure. However, it was not effective against eggs of both species at all exposure periods. Ozonation has potential for the control of some stored grain insect pests on wheat.

Effects of Low Ozone Concentrations and Short Exposure Times on the Mortality of Immature Stages of the Indian Meal Moth, Plodia Interpunctella (Lepidoptera: Pyralidae)

“…Also, Isikber and Oztekin (2009) found that pupae of T. confusum were more resistant to ozone than larvae. In contrast to the present results, Bonjour et al (2011) evaluating the efficacy of ozone fumigation against the major grain pests in stored wheat, reported that pupae of P. interpunctella were more susceptible than eggs and larvae.…”

“…Niakousari et al (2010) reported that a concentration of 4.000 ppm of ozone for 2 h resulted in only 80% mortality of P. interpunctella eggs on date fruits. Bonjour et al (2011) found that ozone at a concentration of 70 ppm for a period of 4 days did not have a significant effect on the eggs of P. interpunctella. These results show that eggs are more resistant to ozone.…”

“…Recently, the feasibility of using ozone to manage stored product pests has received increased attention. Several studies have been carried out on the efficacy of gaseous ozone against stored product insect pests (Erdman 1980;Mason et al 1997;Kells et al 2001;Sousa et al 2008;Bonjour et al 2011;Hansen et al 2012). Ozone also has the potential for controlling insect strains that are resistant against phosphine (Zhangui et al 2003;Sousa et al 2008).…”

Reaction Kinetics of Ozone Gas in Wheat Flour

“…In addition, 100% mortality of Sitophilus oryzae and T. castaneum adults was observed after 2 and 4 d, respectively, following the application of 50 or 70 ppm ozone gas in wheat (BONJOUR et al, 2011); and 100% mortality of S. zeamais and T. castaneum adults and a 96% reduction of Aspergillus flavus was observed following the addition of ozone gas at 258,120 ppm/min in corn kernels (MCDONOUGH et al, 2011a). Full mortality of T. castaneum pupae and eggs and P. interpunctella eggs required a treatment of 180 min, and S. zeamais and S. oryzae, respectively, required 120 and 60 min at 1800 ppm ozone (MCDONOUGH et al, 2011b).…”

Efficacy of Fixed Bed Ozonation Treatment to Control Insects in Stored Bulk Grain

“…In field trials, Kells et al (2001) used a CTP of at least 3,600 ppm-h and consistently achieved 92% to 100% mortality for adult MW and adult RFB in their studies. In field trials, Bonjour et al (2008Bonjour et al ( , 2011 observed 100% mortality of adult RFB with a CTP of 4,800 ppm-h and of adult rice weevil (RW) with 2,400 ppm-h. Based on the limited literature available, it appears that the CTP for effective insect control varies by species and life stages, and requires further investigation. However, based on these laboratory experiments and field trials, it can be assumed that aiming for a CTP of at least 3,600 ppm-h should result in 90% to 100% mortality of adult-stored product insects.…”