. Elementary entomology. Entomology. Fig. 25. Types of insect legs A, grasshopper {ScMstocerca ama-icmia) ; B, a cicindelid beetle {Cichtdela b-guiiata) ; C. a gyrinid beetle {Dincntcs vitlatiis) ; Z), ayoung mantis ; E, a mole cricket {G)yllotalpa borcalis) In aquatic forms the legs are variously developed for swimming or skimming over the surface. The males frequently have the fore- legs developed for grasping the females, as in the suckerlike disks on the fore tarsi of the predacious diving beetles {Dytiscidac). In general, insects which are strong fliers and are usually on the wing have we
. Elementary entomology. Entomology. Fig. 25. Types of insect legs A, grasshopper {ScMstocerca ama-icmia) ; B, a cicindelid beetle {Cichtdela b-guiiata) ; C. a gyrinid beetle {Dincntcs vitlatiis) ; Z), ayoung mantis ; E, a mole cricket {G)yllotalpa borcalis) In aquatic forms the legs are variously developed for swimming or skimming over the surface. The males frequently have the fore- legs developed for grasping the females, as in the suckerlike disks on the fore tarsi of the predacious diving beetles {Dytiscidac). In general, insects which are strong fliers and are usually on the wing have weak legs. Wings. Millions of years ago insects became the pioneers in aerial navigation by the development of wings, which have un- doubtedly been chiefly responsible for the enormous development of insects as a class, living in all latitudes and environments. The largest existing insects are certain tropical moths whose wings expand nearly a foot, but fossils from the coal age show that immense phasmids (nearly related to grasshoppers) then existed, with a wing ex- panse of over two feet. The largest wings are not, however, always the most serviceable, and the strongest fliers are usually of medium size. ThejwingS-PE£- sent a variation of structure in almost every group, and, with the. .fiADlVS Fig. 26. Hypothetical type of wing venation (Adapted from Comstock and Needham). 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 Sanderson, Dwight, 1878-1944; Jackson, C. F. (Cicero Floyd), b. 1882; Metcalf Collection (North Carolina State University). NCRS. Boston, Ginn
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Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
