#1
Not only the tephritids, but also many pretty nice Neotropical pterocallines (
Pterocalla, Xanthacrona, Megalaemyia and allied genera) have peculiar pouches between the 3rd and 4th or also 4th and 5th tergites. Neither Elena, nor I have ever observed live specimens with those things everted, but all the museum stuff critical point dried from alcohol has them.
I attach a single picture of a new undescribed species of
Megalaemyia near
radiata Hendel from Ecuador.
Pardons for the picture quality - my soap box 5 mp camera through the dissecting microsope eyepiece was my only tool at the Smithsonian the last month.