Studies on the changes in taste reception that occurred associated with speciation of insects

(1)研究了几种玉米螟属植物对甾体激素的味觉电生理反应。20-羟基脱皮素（20E）对nubilia Ostrinia nubilalis、肩胛骨ostrinalis、东方Ostrinia orientalis和新西兰Ostrinia zealis有较强的响应，而furnacalis和palustralis对20E的响应较弱。大纹夜蛾的反应为中等。因此，Ostrinia对植物甾体激素的敏感性与摄食习性之间没有明确的关系。(2)行为生物测定表明，人工饲养的日本Ostrinia zealis、furnacalis、scapulalis和latipenis幼虫的草中含有抑制产卵的化学物质。这些化学物质可以用丙酮提取，可以分成己烷可溶的部分，并进一步分馏成酸性部分。酸性部分主要包括棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸。这些游离脂肪酸的含量和组成在4种玉米螟中无显著差异。五种天然脂肪酸的混合物对四种玉米螟都有明显的产卵抑制作用。(3)采用气相色谱法和气相色谱-质谱法研究了日本香薷和日本花椒精油的化学成分。共鉴定出67种成分，其中棕榈酸（14.42%）、石竹烯氧化物（12.57%）、蓖麻醇（6.31%）、五酸（6.28%）和肉豆蔻酸（4.66%）为主要成分。黄参叶精油的主要成分为b -石竹烯（22%）和丙烯（15%）。根油的主要成分为天竺葵酸（18%）、薄荷烯（10%）和-茶树烯（10%）。花茎油的主要成分为戊二烯（12%）和a-铃兰烯（11%）。

(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.