Smoky membranous wing with R thickened is found in

A smoky membranous wing with R thickened is found in Embioptera.
The order Embioptera, commonly known as webspinners or footspinners, is a small group of mostly tropical and subtropical insects, classified under the subclass Pterygota.
The name Embioptera ("lively wings") comes from Greek (embios), meaning "lively", and (pteron), meaning "wing", name that has not been considered to be particularly descriptive for this group of fliers, perhaps instead referring to their remarkable speed of movement both forward and backward.
The wings have a crosswise crease, allowing them to fold forwards and enabling the male to dart backwards without the wings snagging the fabric.