The respiration rate of PH3 susceptible strain was significantly higher than the resistant strain. The results showed no significant effect of oxygen level on the respiration rate of both strains. Phosphine reduced the respiration rate of both strains when it was applied in average concentrations. However, the rate of respiration of the resistant beetles increased significantly under a high level of phosphine. The increase of respiration rate was associated with the higher emission of VOCs which prove the acceleration of metabolic processes to face the phosphine action for survival. Flat grain beetle Cryptolestes pusillus and rusty grain beetle C. ferrugineus are similar insect species, but only C. ferrugineus is capable to develop a high phosphine resistance. A direct immersion solid phase microextraction gas chromatography-mass spectrometry (DI-SPME-GCMS) technology has identified the different fatty acids from PH3 resistant and susceptible strain of Tribolium castaneum.

Fumigation - one of the chemical methods - is the art of dispensing and applying gaseous substances especially for the purpose of disinfecting. It is an old and widely used technique for disinfestation of postharvest grain, fruit and vegetable. In a fumigation procedure, a gas is added to an enclosure for the purpose of controlling or eliminating undesirable organisms. The organisms may be pests of various types - such as insects, rodents, mites, and birds - or micro-organisms, or particular plants or seeds. The enclosure can be made from a diverse range of materials, including metal, concrete, bricks, mud and various plastic membranes. It is necessary to contain the fumigant while it acts on the target organism and to restrict its escape into areas where it may be dangerous to human health. In many situations fumigation may be the only feasible process for pest control as it does not require the commodity to be moved. Neither might it need specialized apparatuses, electricity, or manpower, and is relatively easy to apply in comparison with other methods, for example, heating and irradiation, as well as the use of protectants to control insects. Because fumigation is often the cheapest and most effective process available, it plays a major, world-wide, role in preserving commodities. However, researchers and operators not always fully understand principle of fumigant and fumigation practice to ensure select right fumigant and exposure time on different target insect pests and host commodities as well as application methods.

To replace methyl bromide (MeBr) due to its ozone depletion properties and the life-threatening to related worker as well as fumigators, ethyl formate (EF) fumigation on exported and imported fruits and vegetables has been developed by QIA in Korea since 2005. The benefits of using ethyl formate (EF) fumigant is considered as the safest practice among the commercially available chemical alternatives. The issues was that the cylinderized EF with carbon doxide (CO2) is not enough to extend their applications in terms of fumigation cost. We have developed the cost-effective liquid EF applications with nitrogen gas and demonstrated in quarantine trials (10m3) on imported bananas. We showed the new 35 gm-3 of EF applications with inert gas (nitrogen), were completely control all stage of citrus mealybug (Planoccous citri) for 4hr fumigation at 13°C. These applications meet the quarantine guidelines and protocols in terms of efficacies to target pest and safety concern as well as satisfactions of consumers showing no damages to imported bananas. Extensively, this cost effective EF technology could be acceptable to other fruit and vegetable commodities to reduce the fumigation costs and green house gas (CO2).