Spiders are one of the largest orders of the class Arachnida

Includes cidadas, spittle bugs, leafhoppers and planthoppers. Complex tymbal acoustic system and aristoid antennal flagellum. Labium, originates from the posterior region of the head

Includes the psyllids, white flies, aphids, coccids, mealybugs and scale insects. Vannus and vannal fold in the hind wing absent, movement of the mouth-parts so far posteriorly that the labium originates from the prosternum.

9–200 mm in length, 27–191 pairs of legs, a slender body of 33 or more segments, filiform antennae with 14 segments and no ocelli