Fig. 42.—Nemoptera Extensa.
The Neuroptera may be divided into three great sub-divisions, according to certain well-defined characteristics. The modern tendency is to raise each of these sub-divisions to the rank of orders.
The Neuroptera may be classified as follows:—
[Sub-Order 1, Planipennia], or true Neuroptera.
Metamorphoses complete, larvæ, mostly terrestrial.
[Sub-Order 2, Trichoptera], or hairy-winged Neuroptera.
Metamorphoses complete, larvæ aquatic. Wings of Imago clothed with hairs.
[Sub-Order 3, Pseudo-Neuroptera], or false Neuroptera.
Metamorphoses incomplete.
The most important distinction between the first two groups and the third is that the former undergo complete metamorphoses, whereas in the latter the transformations are incomplete or imperfect. The latter for this reason are often classified as a separate order.