The Animal Parasites of Man

by Harold Benjamin Fantham; Max Braun; J. W. W. Stephens; Fred. V. Theobald

[The most usual and recent classification of the Hexapoda is the following:—

(1) Aptera.—Wingless insects; scarcely any metamorphosis.

(2) Neuroptera.—Four membranous wings, frequently with much network; the front pair not much, if at all, harder than the under pair; the latter with but little or no fan-like action in closing; mandibulate; metamorphosis variable, but rarely complete.

(3) Orthoptera.—Four wings; front pair coriaceous or leather-like, usually smaller than the other pair, which are of more delicate texture and contract in repose like a fan; mandibulate; metamorphosis complete.

(4) Thysanoptera.—Four very narrow fringed wings; mouth imperfectly suctorial; metamorphosis slight.

(5) Hemiptera.—Four wings; the front pair either all transparent or with the basal half leathery; mouth suctorial; metamorphosis slight.

(6) Diptera.—Two membranous wings only; mouth suctorial, very varied; metamorphosis complete.

(7) Lepidoptera.—Four large wings covered with scales; mouth suctorial, metamorphosis great.

(8) Hymenoptera.—Four membranous wings; front pair larger than hind, which do not fold up in repose; mandibulate, sometimes with a tubular proboscis; metamorphosis complete.