File:Image from page 088 of "Introduction to zoology; a guide to the study of animals, for the use of secondary schools;" (1900) (14598333418).jpg

Identifier: introductiontozo00dave Title: Introduction to zoology; a guide to the study of animals, for the use of secondary schools; Year: 1900 (1900s) Authors: Davenport, Charles Benedict, 1866-1944 Davenport, Gertrude Anna Crotty, 1866- Subjects: Zoology Publisher: New York, Macmillan company London, Macmillian and co., ltd. Contributing Library: MBLWHOI Library Digitizing Sponsor: MBLWHOI Library

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Text Appearing Before Image: because it infests wheat seedlings and so weakens them that they produce no grain. Other minute gnats or midges are destructive to clover in the United States, either by binding the leaves together and sucking the sap of the plant or by destroying the young seed. The mosquitoes, or Culicidse,1 are so well known that it is hardly necessary to describe them. They can always be F - identified by the feathery an-tennae, by the presence of a fringe of hairs on the hind margin of the wing, and by the fact that the marginal vein runs all around the periphery of the wing. The larvae areusually aquatic, but somespecies which are abun-dant on our Western aridplains must breed in theearth. The eggs of theaquatic species are laid ina boat-shaped mass, whichfloats on the surface of the — Cecidomyia, the Hessian-fly. <i, larva; b, pupa. Fromthe • Standard Natural History.

Text Appearing After Image: B FIG. 71.— Culex, the mosquito. A, larva;c, its respiratory tube. B, pupa; cl, therespiratory tubes; a, the end of the niing appendages, dorsal view. Afterdrawing of E. Burgess. water. The larvae escape abdomen with the two oar-like swim- from the lower ends of the egg-cases, and are knownas wiskiers. The larvse o o rest vertically near the surface of the water, head downward,with the tail end of the body at the surface of the water,1 Culex was Plinys name for the fly. 70 ZOOLOGY since respiration takes place at that end (Fig. 71, A, <?).Upon emerging from the water, the mosquito floats in itspupal skin until its legs and wings harden. Since a dis-turbance in the water at this time would jeopardize thelife of the mosquito, this insect always breeds in quietwaters. From the habits of the larvre, it follows that theycan be easily killed while in the pond by pouring keroseneoil on the water, for this forms a film on the surface and

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