Page:First course in biology (IA firstcourseinbio00bailrich).pdf/318

 TABLE FOR CLASSIFYING INSECTS (class Insecta) INTO ORDERS

A_{1} Biting Insects; mouth parts for grasping and biting

B_{1} Wingless; changes (metamorphosis) incomplete                                      (Aptera)

B_{2} Under wings thinner than upper wings, and fold like a fan beneath them; changes       (Orthoptera) incomplete

B_{3} Upper wings hard and thick, protecting under wings, which fold both lengthwise         (Coleoptera) and crosswise beneath them; changes incomplete

B_{4} All four wings nearly alike, finely veined, transparent

C_{1} Hind wings smaller than fore, two or three filaments attached to abdomen,      (Neuroptera) antennæ long; changes complete

C_{2} Hind wings not smaller than fore; no filaments on abdomen, antennæ inconspicuous; changes incomplete         (Pseudoneuroptera)

A_{2} Sucking Insects; mouth parts for sucking or licking

B_{1} Basal half of upper wing usually leathery, other half of wing transparent; lower lips       (Hemiptera) transformed into a tube; true bugs

B_{2} Four wings covered by scales, holding-jaws (maxillæ) elongated to form a sucking            (Lepidoptera) tube coiled under head; changes complete

B_{3} Four wings, membranous, hind wings hook to fore wings in flight; mouth parts        (Hymenoptera) for both biting and sucking; abdomen with sting; changes complete

B_{4} Two wings, mandibles rudimentary, mouth a soft beak                                 (Diptera)

B_{5} No wings, mandibles rudimentary, mouth a horny beak                                    (Siphonoptera)