The importance of long-chain alkanes and free fatty acids present in leaf surface waxes of two Commelinaceae rice-field weeds, Commelina benghalensis L. and Murdannia nudiflora (L.) Brenan, was evaluated as short-range attractant and oviposition stimulant in the Lema praeusta (Fab.) (Coleoptera: Chrysomelidae). Surface waxes were extracted by dipping leaves in n-hexane for 1 min at 27 ± 1 °C. Thin-layer chromatography, gas chromatography–mass spectrometry, and gas chromatography–flame ionization detection analyses of n-hexane extracts revealed 20 n-alkanes from C₁₄ to C₃₆ and 13 free fatty acids from C12:0 to C22:0. Pentacosane and palmitoleic acid were predominant among n-alkanes and free fatty acids, respectively. Females showed attraction to one leaf equivalent surface wax of both weeds against the control solvent (petroleum ether) in Y-tube olfactometer bioassays. However, the insect could not discriminate between one leaf equivalent surface waxes of two weeds, suggesting that both weeds were equally attractive to females. Among all identified alkanes and fatty acids, females showed attraction towards individual docosane, tricosane, pentacosane and heptacosane, and tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis and M. nudiflora, respectively. A synthetic blend of either docosane, tricosane, pentacosane, and heptacosane, resembling in amounts as present in one leaf equivalent surface wax of C. benghalensis, or tridecanoic acid, palmitoleic acid, linoleic acid, and arachidic acid, resembling in amounts as present in one leaf equivalent surface wax of M. nudiflora, served as short-range attractant and oviposition stimulant in L. praeusta.

中文翻译：

---

稻田杂草的甲虫生物防治剂通过表面蜡长链烷烃和游离脂肪酸识别其寄主植物

两种Commelinaceae稻田杂草（Commelina benghalensis L.和Murdannia nudiflora（L.）Brenan）的叶表面蜡中存在的长链烷烃和游离脂肪酸的重要性被评估为Lema中的短程引诱剂和产卵刺激剂praeusta（Fab。）（鞘翅目：金眼科）。表面的蜡通过浸渍叶提取Ñ正己烷在27±1℃下1分钟。的薄层色谱法，气相色谱-质谱法和气相色谱-火焰电离检测分析ñ -己烷提取物显示20 ñ -烷烃选自C ₁₄至C ₃₆从C12：0到C22：0的13种游离脂肪酸。在正构烷烃和游离脂肪酸中，戊四烷和棕榈油酸分别占主导地位。在Y型管嗅觉仪生物测定法中，雌性对两种杂草的一叶当量表面蜡显示出对对照溶剂（石油醚）的吸引力。但是，该昆虫无法区分两种杂草的一叶当量表面蜡，表明这两种杂草对雌性同样具有吸引力。在所有鉴定出的烷烃和脂肪酸中，雌性对单个的二十二烷，十三烷，戊烷和庚烷以及十三烷酸，棕榈油酸，亚油酸和花生四烯酸具有吸引力，其含量与一朵等效孟加拉孟加拉蜡的表面蜡中的含量相似。和M. nudiflora分别。一种合成共混物二十二烷任一，二十三烷，二十五烷的，和二十七烷，类似在的一个叶等效表面蜡量作为本C.火柴头，或十三烷酸，棕榈油酸，亚油酸和花生酸，在类似量作为本的一个叶等效表面蜡M.裸花，担任短程引诱和产卵兴奋剂在L. praeusta。