Figure 2

Anatomy of cream (c), orange (o), black (k), and blue (b) wing scales. A-D Light microscopy. E-H Transmission electron microscopy. I-L Scanning electron microscopy. In A and C the wing membrane substrate (arrows) has on both sides cream and black scales, respectively. The section of D was stained with Azur II to visualize the unpigmented blue scale, which is situated above two black scales. The upper lamina has in E (asterisk) and G a high electron density, but in the lower lamina (E, white arrow) the electron density is low. The lower lamina of the blue scales consists of two membranes (H, arrows) with local connections. Membranous structures can be seen between crossribs (e.g., arrowhead in J). Scale bars: A-D 20 μm. E-L 2 μm.