2. Mallophaga: Parasitic wingless Corrodentia (Bird-lice).
Order: Ephemeroptera.
Jaws vestigial. Fore-wings much larger than hind-wings. Elongate, jointed cerci. Genital ducts paired and entirely mesodermal. Malpighian tubes numerous (40). Aquatic larvae with distinct maxillulae, breathing dissolved air by abdominal tracheal gills. Penultimate instar a flying sub-imago. [Includes the single family of the Ephemeridae or may-flies. See also [Neuroptera], in which this order was formerly comprised.]
Order: Odonata.
Biting mandibles. Wings of both pairs closely alike; firm and glassy in texture. Prominent, unjointed cerci, male with genital armature on second abdominal segment. Malpighian tubes numerous (50-60). Aquatic larvae with caudal leaf-gills or with rectal tracheal system.
Includes the three families of dragon-flies. Formerly comprised among the Neuroptera.
Order: Thysanoptera.
Piercing mandibles, retracted within the head-capsule. First maxillae also modified as piercers; maxillae of both pairs with distinct palps. Both pairs of wings similar, narrow and fringed. Four Malpighian tubes. Cerci absent. Ovipositor usually present. Young resembling parents, but penultimate instar passive and enclosed in a filmy pellicle.
Includes three families of Thrips (see [Thysanoptera]).
Order: Hemiptera.