Fig. 1

Cuticle ultrastructure by transmission electron microscopy. Legend Transmission electron micrographs of the cuticles in adult abdomen (a,b), L4 larval abdomen (d,e) and L4 anal papillae (g,h) from brackish (a,d,g) and fresh water (b,e,h) Ae. aegypti. Arrowheads mark the external surface. Box plots show the range (whiskers), median (horizontal line), and 25th and 75th percentile of measured thicknesses (box) of the whole cuticle of adult abdomen (c), L4 larval abdomen (f) and L4 anal papillae (i). n = total number of measurements (at least ten measurements per insect). *** p-value< 0.001 by the two-tailed Student’s t test. BW, brackish water; FW, fresh water; en, endocuticle; ex, exocuticle. Black scale bars represent 500 nm. White bars in a,b,d and e delineate the endocuticle and exocuticle