部分蝽类昆虫翅表微纳结构与浸润性研究

Microstructure and wettability of the wing surface of some stink bugs

蝽类昆虫属于半翅目Hemiptera异翅亚目Heteroptera,其前翅基半部骨化成革质,比端半部膜质要硬得多。本研究采用接触角测量仪、扫描电子显微镜、傅里叶红外光谱仪对20种蝽类昆虫前翅的革质、膜质区浸润性、微观结构和化学成分进行了研究。研究结果显示:(1)蝽类昆虫翅表浸润性存在明显差异,接触角为40.66°~138.37°。(2)6种蝽类昆虫翅表革质区比膜质区的疏水性强,具有乳突、不规则凸起、皱纹和刚毛等粗糙结构。特别是柱状乳突结构(直径0.702±0.170μm,高度1.516±0.293μm,间距1.191±0.132μm)有效地使革质区表面更疏水。相反,4种蝽类昆虫翅表的膜质区比革质区更疏水,椭圆形突起、褶皱和分泌物密度更高。而在10种蝽类昆虫中,疏水性没有显著差异,革质和膜质区的翅面结构相似,仅具有大小不一的隆起和分泌物。(3)蝽类昆虫翅表分布着长链烃类、脂肪酸酯和脂肪酸醇构成的蜡质层。栖息于植物中上层的蝽类昆虫疏水性较强。蝽类昆虫不同硬度的翅表的浸润性归因于微米级微观结构和表面蜡质层的联合效应及生境的协同作用。本研究结果可为不同硬度、不同质地、不同结构、不同性能的材料的一次性制备以及衔接提供有意义的参考价值。

Stink bugs belong to Hemiptera,and the proximal part of their forewings has sclerotized into leathery region,which is much harder than the posterior membranous region.We studied the microstructure,chemical property and wettability of both the leathery and membranous regions of the forewing of 20 stink bug species,using the contact angle measuring instrument,scanning electron microscope and fourier transform infrared spectrometer.Our research results showed that the wettability of the wing surface of the stink bugs was obviously different,and the contact angle ranges from 40.66°to 138.37°.In six species,the leathery region of wing surface,which showed stronger hydrophobicity than the membranous region,had rough structures such as papillae,irregular protrusions,wrinkles and bristles.Especially,the columnar papillae structure(the diameter was 0.769±0.171μm,the height was 1.516±0.293μm,and the spacing was 1.191±0.132μm)efficiently made the surface of the leathery area more hydrophobic.Conversely,in 4 species,the membranous region of wing surface,which was more hydrophobic than the leathery region,had a higher density of elliptical bumps,folds and secretions.While in ten species there was no significant difference in hydrophobicity,and the wing surface structures in the leathery and membranous regions were similar and only had variable sized bulges and secretions.Furthermore,a waxy layer composing of long-chain hydrocarbons,fatty acid esters and fatty acid alcohols was found on the wing surfaces.Ecologically,the stink bugs that inhabited the upper and middle layers of their host plants were much hydrophobic.So,the wettability of the wing surface of stink bugs with different hardness could be attributed to the combined effect of the microstructure and waxy surface layer and the synergistic effect of their habitat.The results of this study can provide a useful reference for the disposable preparation and cohesion of materials with different hardness,textures,structures and properties.