识别特征Diagnosis Antennae short,6-10 segments Head narrow anteriorly forming a conical mouth opening winged or wingless;wings distinctive strap-like with setal fringe翅脉极少或无，最多只有1- 2条纵脉；Many species are secondarily wingless. Tarsi 1-2 segmented,with eversibl adhesive bladders apically 过渐变态一、 识别特征Diagnosis • Antennae short, 6-10 segments • Head narrow anteriorly forming a conical mouth opening • winged or wingless; wings distinctive strap-like with setal fringe 翅脉极少或无，最多只有1－ 2条纵脉；Many species are secondarily wingless. • Tarsi 1-2 segmented, with eversible adhesive bladders apically • 过渐变态