. Insect life; an introduction to nature study and a guide for teachers, students and others interested in out-of-door life. Entomology; Nature study. BROOK LIFE. 157. Fig. 127.—Cocoon and larva of a black-fly. brinks of falls and places where the slanting bed-rock is washed clean by a swift flow of water, but some- times they cling to pieces of wood or small stones that are firmly fixed in the rapids. When the larvae are fully grown they spin boot- shaped cocoons within which the pupa state is passed; these are firmly fastened to the rock upon which the larvas lived. In Fig. 127 there are rep
. Insect life; an introduction to nature study and a guide for teachers, students and others interested in out-of-door life. Entomology; Nature study. BROOK LIFE. 157. Fig. 127.—Cocoon and larva of a black-fly. brinks of falls and places where the slanting bed-rock is washed clean by a swift flow of water, but some- times they cling to pieces of wood or small stones that are firmly fixed in the rapids. When the larvae are fully grown they spin boot- shaped cocoons within which the pupa state is passed; these are firmly fastened to the rock upon which the larvas lived. In Fig. 127 there are represented a larva and a cocoon. 1. Find a cluster of larvas and take notes on the following: The way in which they keep their place in the swift current. (It is the tail end by which they are usually fastened to rock.) Their method of locomotion, and the action of the fan-shaped or- gans attached to the head. 2. Collect larvae and cocoons and try to keep them alive in water. These insects can not be reared in aquaria unless they are placed under a jet of water, but they can be kept alive several hours, thus giving some opportunity for watching their habits in con- finement. 3. Look for the eggs of the black-flies. These are yellowish or brownish and occur in patches in situations similar to those inhabited by the larvae. 4. Look also for adults. These occur in swarms, hovering over the brinks of falls and dashing back and forth through the spray. Sometimes they may be seen darting into the water and out again ; at such times they are laying their eggs. Fig. 128 represents one of these flies somewhat. 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 original Comstock, John Henry, 1849-1931; Comstock, Anna Botsford, 1854-1930. New York, D. Appleton and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomol, bookyear1901
