THE NEW TECHNIQUE OF LIGHT-MICROSCOPIC SURFACE-SCANNING (LMSS) FOR STUDYING THE SURFACE OF THE TRANSPARENT CUTICLE OF SMALL INSECTS

The recently developed new exsur technique of light microscopic surfac e scanning (LMSS) for studying the surface patterns of wings in insect s of the Order Tubulifera is discussed. It is eminently suited for det ailed study of the surface of transparent, colourless cuticular membra nes. The exsur technique emulates results from Electron Microscopic Su rface Scanning (EMSS), but has some technical limitations. The LMSS is not a substitute for EMSS, but the practical advantages of the new te chnique as a routine method far outweigh these limitations. Exsur prep arations of the wings of Tubulifera have provided a suite of new chara cters that enable new insights into their structure and phylogenetic r elationships. The technique is also useful for studying the surface de tails of various parts of the body. It can be used routinely, does not require any sophisticated instrumentation, and does not permanently a lter the material. It opens a new window for looking at the complexiti es of the surface features that are practically invisible with the con ventional immerse preparations. The results obtained from using this t echnique on other small insects, like Trichogrammatidae, are also pres ented in this paper.