Development of a new measure for controlling pine wilt disease using oviposition deterrents of insect vector, Monochamus alternatus

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Monochamus alternates females deposit jelly-like substance near the eggs just after opposition. The substance deterred the conspecific females from opposition. Colorless to pale yellow, transparent liquid was present in the long spermathecal gland of living females and changed to amber, transparent, elastic substance after females died, which greatly resembled jelly-like substance in opposition scars. Methanol extract of spermathecal gland deterred females from opposition. Section showed that the liquid in spermathecal gland was found in bursa copulatrix. The facts showed that spermathecal gland produced the oviposition deterrents. When methanol extract of spermathecal gland was fractionated with acetone and methanol, methanol-insoluble fraction showed an oviposition-deterring effect. Treatment with cold methanol after concentration divided the active fraction into methanol-insoluble fraction including protein and methanol-soluble fraction. Neither of the two fractions had oviposition- … More deterring effect. A mixture of them could not recover the activity. Methanol extract of fresh larval frass deterred females from opposition. The extract was fractionated with benzene, chloroform, acetone, and methanol. As only the benzene-soluble fraction showed an oviposition-deterring effect, it was fractionated into six fractions by successive silica gel column chromatography. Hexane-soluble fraction of them had an oviposition-deterring effect. The hexanesoluble fraction was partitioned into five fractions by column chromatography. As the resulting benzene soluble and methanol-soluble fractions showed an oviposition-deterring effect, both fractions were subjected to TLC analysis, where 7 and 3 spots were observed, respectively. Substances of one spot from benzene fraction showed an oviposition-deterring effect. GC and GC-MS revealed the presence of 6 compounds. Acetophenone thus identified showed the greatest oviposition-deterring effect among the compounds although there was no statistical significance. Less