. A manual for the study of insects. Insects. 528 THE STUD V OF INSECTS, plants; in others they are provided with floats and let loose in the water; and in still other species the cases are carried by the mother underneath her body and steadied with her hind legs. Frequently some of the young larvae devour their companions ; in this way the size of the family is de- creased before it escapes from the egg-case. Later they live upon insects that fall into the water and upon snails. These larvae resemble somewhat those of the Dytiscidae; but the body is much more plump, and the mandibles are of m
. A manual for the study of insects. Insects. 528 THE STUD V OF INSECTS, plants; in others they are provided with floats and let loose in the water; and in still other species the cases are carried by the mother underneath her body and steadied with her hind legs. Frequently some of the young larvae devour their companions ; in this way the size of the family is de- creased before it escapes from the egg-case. Later they live upon insects that fall into the water and upon snails. These larvae resemble somewhat those of the Dytiscidae; but the body is much more plump, and the mandibles are of moderate size. A very interesting observation on the mode of feeding of one of these larvae has been published. It cap- tured a fly, and swarn with it rapidly through the water to a leaf near the surface. It then rested on this leaf, and, rais- ing its head out of the water, crushed the fly to pulp with its jaws, letting the blood run into its open mouth. The Hydrophilidse are represented in North America by about one hundred and fifty species. Our three largest be- long to the genus Hydrophilus (Hy-droph'i-lus). In this genus the metasternum is prolonged backward into a spine between the hind legs, and the ster- num of the prothorax bears a deep furrow. Our most common species is Hydrophilus triangularis (H. tri-an-gu- la'ris) (Fig. 637). The beetles of the genus Tropister- nus (Trop-i-ster'nus) agree with Hy- drophilus in the form of the proster- num and metasternum, but differ in size, our species measuring less than one-half inch in length. The most common species in the East is Tropi- sternus glaber (T. gla^ber), and, on the Pacific coast, T, calif or nictis. Next in size to Hydrophilus are several species of Hy- drocharis (Hy-droch'a-ris). In this genus the metasternum is prolonged somewhat, but does not form a long, sharp. Fig. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and
Size: 1285px × 1945px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectinsects, bookyear1895
