. Class book of economic entomology [microform] : with special reference to the economic insects of the northern United States and Canada. Insect pests; Entomologie; Entomology; Insectes nuisibles, Lutte contre les; Insect pests; Insectes nuisibles. 34 ECONOMIC ENTOMOLOGY The cruciform type prevails among the holometabola. The body is cylindrical, and the legs, antenna; and cerci are much reduced. Many transitional forms, however, occur, and it is believed that the eruciform type has been developed from the thysinuriform. Ecdysis or Moulling.~AU larvae shed their outer skin (cuticula), at inte
. Class book of economic entomology [microform] : with special reference to the economic insects of the northern United States and Canada. Insect pests; Entomologie; Entomology; Insectes nuisibles, Lutte contre les; Insect pests; Insectes nuisibles. 34 ECONOMIC ENTOMOLOGY The cruciform type prevails among the holometabola. The body is cylindrical, and the legs, antenna; and cerci are much reduced. Many transitional forms, however, occur, and it is believed that the eruciform type has been developed from the thysinuriform. Ecdysis or Moulling.~AU larvae shed their outer skin (cuticula), at intervals to allow for growth. The number of moults varies in different insects, but is constant for the same species under the same conditions. In the Lepidoptera the larva is known as a caterpillar, and is char- acterized by the possession of three pairs of true legs, and usually. 4mi,^ Fig. 38.—Types of larvs. o. Grub of asparagus beetle; b, cutworm; c, cabbage root maggot; d, fall canker worm; e, maggot of honey bee; /. spring canker worm; i. false caterpillar of saw fly; h—a, b, c. nymphs of locust; i—a, b, c. d, e, nymphs of squash bug. {After various aulkon.) five pairs of prolegs on the abdominal segments. In the Diptera and Hymenoptera the larva is a maggot, characterized by the absence of legs. In the group of Saw-flies of the Hymenoptera, however, the larvx are caterpillar-like, possessing three pairs of true legs and often seven or more pairs of prolegs. In the Coleoptera the larva is termed a grub, and has usually but three pairs of legs (Fig. 38). Classificatioii of Lorrs.—Escherich classifies larva; us follows: Primary Larvd.—Larva like the adult, and without provisional larval orgaii —Tkymnura, XfMnpkaia, Prdktilittir, Orthopiera, Iwplera, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectentomology, bookyear1
