. A text-book of agricultural zoology. Zoology, Economic. 196 DIl'TERA OK TKUE FLIES. Diptera there is also much variation : some have sucking mouths {Bombylius), others piercing mouths {Tabanus or the Gad-fly), fig. 101; in the Warble-flies (OEstridce) the mouth is rudimentary, the adults taking no nourishment. There is never a sting; flies can wound by piercing with the mouth, but not, as is often supposed, by stinging. The labium of the mouth (fig. 101, li) is greatly elongated, and forms a kind of gutter for the reception of the lancet-shaped maxillse and mandibles. The proboscis, made up
. A text-book of agricultural zoology. Zoology, Economic. 196 DIl'TERA OK TKUE FLIES. Diptera there is also much variation : some have sucking mouths {Bombylius), others piercing mouths {Tabanus or the Gad-fly), fig. 101; in the Warble-flies (OEstridce) the mouth is rudimentary, the adults taking no nourishment. There is never a sting; flies can wound by piercing with the mouth, but not, as is often supposed, by stinging. The labium of the mouth (fig. 101, li) is greatly elongated, and forms a kind of gutter for the reception of the lancet-shaped maxillse and mandibles. The proboscis, made up of the labium, &c., ends in a fleshy swoUen tongue, and is closed above by the labrum. There are no true labial palpi. The head is large, and united to the thorax by a very short neck. The thorax is large and compact, the prothorax closely united to the mesothorax, and forming a thin coUar. The eggs of flies are usually oval or spindle-shaped bodies, of a white or black colour, sometimes laid singly, at others in groups. The larvEe are mostly white footless maggots; no true legs are ever present. Thirteen segments is the usual nimiber present, but in some fourteen may be found (fig. 93, a). The head may be horny or may be reduced .to a simple pair of hooks, the mandibles (fig. 107, d); the body may be naked (fig. 93, a) or with bristles (fig. 109). Most are terrestrial, but some are aquatic—Cvlicidoe (Gnats), Qhironomidm (Midges) (fig. 92), and Eristalidm (Eat- tailed Flies). The genera Volucdla, Tachina, and Conops are parasitic on other insects ; the genera CEstrm and Sarcophagus, &c., on vertebrates. When mature, dipterous larvae may or may not cast off the larval skin. The naked pupse (fig. 97) are veiy varied, often armed with spines and bristles (fig. 99, 5). Those that retain the larval skin as a case are called "puparia,". Fig. 92.—Plumed Gnat (Clmrontymis pJumosMs.). Please note that these images are extracted from scanned page images that may hav
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1899
