Ultra-thin sections (~90 nm) of pharate adults (5 d-old pupae) that were injected with dsTcVer (200 ng per insect) in late instar larvae were incubated with gold-labeled (10 nm) WGA to detect chitin in the dorsal side of elytral cuticle. dsRNA for chitin synthase-A (dsTcChs-A), which is required for cuticular chitin synthesis, was injected as a negative control. Chitin was detected in both horizontal laminae and vertical PCFs of elytral cuticle from dsTcVer-treated insects (A and C). Few or no gold particles were observed in TcChs-A-deficient insects (B and D). EN, envelope; EP, epicuticle; PRO, procuticle; PCF, pore canal fibers; APMP, apical plasma membrane protrusion. Scale bar in A and B = 1 μm and C and D = 500 nm. From Noh et al., (2015) [22].