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

(1)研究了几种亚洲玉米象的味觉器官对植物蜕皮激素的电生理反应，其中亚洲玉米象、肩天牛、东方玉米象和欧洲玉米象对20-羟基蜕皮酮(20E)有较强的反应，而亚洲玉米象和沼泽玉米草对20-羟基蜕皮酮(20E)的反应较弱。宽叶玉米象的反应中等。因此，对植物蜕皮激素的敏感性与亚洲玉米螟的取食习性之间没有明显的关系。(2)行为生物测定表明，在取食人工饲料的亚洲玉米螟、亚洲玉米螟、亚洲玉米象和亚洲玉米象幼虫的幼虫体内含有产卵抑制物质。这些化学物质可以用丙酮提取，可以被分成可溶于正己烷的馏分，然后进一步分馏成酸性馏分。该酸性组分主要为棕榈酸、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四种玉米草之间没有显著差异。在玉米象幼虫幼虫果肉中发现的五种天然脂肪酸的混合物对四种玉米象均有显著的产卵威慑作用。(3)用GC和GC-MS研究了日本大蒜和日本小菜蛾精油的化学成分。共鉴定出67种成分，主要成分为棕榈酸(14.42%)、石竹烯氧化物(12.57%)、胡萝卜醇(6.31%)、十五烷酸(6.28%)和肉豆蔻酸(4.66%)。竹叶挥发油的主要成分为B-石竹烯(22%)和戊烯(15%)。根油的主要成分为当归酸(18%)、马兜铃烯(10%)和α-水仙烯(10%)。花茎油的主要成分是戊烯(12%)和α-水芹烯(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.