Evaluation of the mortality of two stored-product insects by garlic emulsion (Sirinol) in combination with low air pressure

Abstract

Although, there are a large number of suggested potential alternatives to methyl bromide for disinfestations of durable commodities, development alternatives are likely to be costly. The combined factors of methyl bromide phase-out, the gradual development of insect resistance to fumigants and undesirable effects of some fumigants residues in foodstuff, have led to the idea of using controlled atmosphere. In this research, adults of Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) were exposed to various air pressures (first phase) and air pressures together with 150 μL/L Sirinol (second phase) at 27 ± 2°C and 65 ± 5% relative humidity in various durations and mortality rates were determined. Complete mortality of T. castaneum adults was obtained within 1, 3 and 6 h when were subjected to 10, 30 and 50 mmHg, respectively. Adults of R. dominica showed 96.25 and 60% mortality during 3 and 10 h when exposed to 10 and 30 mmHg, respectively. It was revealed that by using 150 μL/L Sirinol in pressure of 50 mmHg for 4 h, mortality rates exceed 86.25 and 42.5% for adults of T. castaneum and R. dominica, respectively. Mortality percentage of the insects which were treated with Sirinol was more than the cohorts that were under vacuum conditions without any Sirinol treatment. Ultimately, data analysis showed that T. castaneum adults are noticeably susceptible to low air pressure and the combination of low air pressure and Sirinol.

Key words: Fumigant, Sirinol, low pressure, stored-products insects.