| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
(1) Electrophysiological responses of the gustatory organs of several Ostrinia species to phytoecdysteroids were investigated.Ostrinia nubilalis, O. scapulalis, O. orientalis and O. zealis strongly responded to 20-hydroxyecdysone (20E), whereas O. furnacalis and O. palustralis responded only moderately. The response of O. latipennis was intermediate. Accordingly, no clear relationships were found between the sensitivity to phytoecdysteroids and the feeding habit of Ostrinia species.
(2) Behavioral bioassays have shown that oviposition-deterring chemicals are involved in the frass of Ostrinia zealis, O. furnacalis, O. scapulalis and O. latipennis larvae fed on an artificial diet. These chemicals were extractable with acetone, could be partitioned into a hexane-soluble fraction, and further fractionated into an acidic fraction. This acidic fraction mainly included palmitic, stearic, oleic, linoleic and linolenic acids. No significant differences among the four Ostrinia species were found in the amount and composition of these free fatty acids. A mixture of the five authentic fatty acids at natural composition as found in the larval frass of O. zealis exhibited significant oviposition-deterring effects on every four Ostrinia species.
(3) The chemical compositions of the essential oils from Cirsium japonicum and Petasites japonicus were investigated by GC and GC-MS. Sixty-seven components were identified in the C. japonicum essential oil, with palmitic acid (14.42%), caryophyllene oxide (12.57%), khusinol (6.31%), pentadecanoic acid (6.28%) and myristic acid (4.66%) as the major components. The major components of the leaf essential oil of P. japonicus were B-caryophyllene (22%) and valencene (15%). The root oil contained angelic acid (18%), eremophilene (10%) and a-phellandrene (10%) as the major components. Valencene (12%) and a-phellandrene (11%) were the main components of the flower stem oil.
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