Effective phytosanitary fumigation can prevent the introduction of exotic insects into new areas where they become pests. Traditionally Probit 9 level control (99.9968%) was considered as a stand-alone quarantine treatment. However, unacceptable phytotoxic damage often associated with high-dose treatment to realize Probit 9 level control of a large number of pests has often restricted its practical application. Therefore, quarantine security is being achieved for some commodities using a “systems approach”, where quarantine pests are cumulatively reduced to acceptable levels using independent, pre- and postharvest measures that comprise a systems that effectively mitigate the pest. Preharvest reductions in population through the study and application of chemical ecology involving insect behavior modifying chemicals can be an integral part of systems approach. This results in low pest prevalence prior to end point treatment, where pests may be effectively controlled using a less-than-Probit 9 level, low-dose treatment. In this talk, I discuss the chemical ecology of invasive quarantine pests including Drosophila suzukii and its perspective in the effective end point fumigation treatment using ethyl formate.

Conventional chemical ecology approach for identification of semiochemicals from natural sources is based on isolation of active ingredients after fraction and bioassay. Instead, we identify potential semiochemicals using reverse chemical ecology approach. In this way, we discovered an odorant receptor (CquiOR136) for DEET, which was not know how and why it work. Additionally, we identified a link between this synthetic repellent and methyl jasmonate, thus suggesting that DEET might work by mimicking defensive methyl jasmoante from plant. Moreover, we serendipitously found that a receptor, CquiOR36, responded to an old sample of nonanal in ethanol. Careful investigation led us to identify the active ligand as acetaldehyde (derived from ethanol) from “contaminants” in the old nonanal sample. We explored that acetaldehyde in a wide range of dose both attracts gravid mosquito and stimulate them to lay eggs in oviposition trays.

A practical and efficient disposal method for chemical dechlorination of PCBs (polychlorinated biphenyls) in transformer oil was evaluated. The transformer oil containing PCBs was treated by the PEG 600 (polyethylene glycol 600) and potassium hydroxide (KOH) along with different reaction temperatures(25, 50, 100 and 150oC) and times(30, 60, 240 and 480 min). The best disposal efficiency of PCBs in transformer oil was attained under the experimental conditions of PEG 600 (2.5 w/w%)/KOH (2.5 w/w%)/150oC/4 hrs, showing completely removal of all PCBs containing 3-9 chlorines on two rings of biphenyl. In studying the reaction of PEG/KOH with PCBs, it confirmed that the process led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.