Entomology : with special reference to its biological and economic aspects . ifications for piercing, lapping or rasping; Thysanopteraare partly mandilmlate but chiefly suctorial; and adult Ephe-merida and Trichoptera have but rudimentarv^ mouth parts. The mandilmlate orders are Thysanura, Collembola (pri-marily), Orthoptera, Platyptera, Plecoptera, Ephemerida(rudimentarily in adult), Odonata, Xeuroptera, ]\Iecopteraand Coleoptera. The mouth parts of an insect consist typically of labniin,mandibles, luaxillcc, labium and liypopluvynx (Fig. 44),though these organs differ greatly in different or
Entomology : with special reference to its biological and economic aspects . ifications for piercing, lapping or rasping; Thysanopteraare partly mandilmlate but chiefly suctorial; and adult Ephe-merida and Trichoptera have but rudimentarv^ mouth parts. The mandilmlate orders are Thysanura, Collembola (pri-marily), Orthoptera, Platyptera, Plecoptera, Ephemerida(rudimentarily in adult), Odonata, Xeuroptera, ]\Iecopteraand Coleoptera. The mouth parts of an insect consist typically of labniin,mandibles, luaxillcc, labium and liypopluvynx (Fig. 44),though these organs differ greatly in different orders of in-sects. The mandibulate, or primary type, from which thesuctorial, or secondary type, has been derived, will be consid-ered first. Mandibulate Type.—The labruin, or upper lip, in biting ANATOMY AND PHYSIOLOGY 37 insects is a simple plate, hing-ed to the clypens and moving upand down, though capal)le of protrusion and retraction to someextent. It covers the mandibles in front and pulls food backto these organs. On the roof of the pharynx, under the la- FiG. Mouth parts of a cockroach, Ischnoptera pennsyhanica. A, labrum; B, mandible;C, hypopharj-nx; D, maxilla; E, labium; c, cardo; g (of maxilla), galea; g (of labium),glossa; /, lacinia; Ip, labial palpus; ni, mentum; mp, maxillary palpus; p, paraglossa;pf, palpifer; pg, palpiger; s, stipes; sm, submentum. B, D and E are in ventralaspect. brum and clypeus, is the epipharynx; this consists of teeth,tubercles or bristles, which serve in some insects merely tohold food, though as a rule the epipharynx in mandibulateinsects bears end-organs of taste (Packard). The mandibles, or jaws proper, move in a transverse plane,being closed by a pair of strong adductor muscles and openedby a pair of weaker abductors. The mandil;)le is almostalways a single solid piece. In herbivorous insects ( A) it is compact, bluntly toothed, and often bears a molar,or crushing, surface behind the incisive teeth. In carnivorous ENTOMO
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
