. Elementary entomology. Entomology. THE NERVE-WINGED INSECTS 97. Fig. 124. A stone-fly (Pieronarcys 7-egalis). reduced) (After Newport, from Folsom) (Slightly larger with each successive molt, until the water nymph sheds its skin for the last time, the gills and mouth-parts are left behind, and the winged May- fly comes forth. After flying a short distance it alights and again sheds its skin, a thin layer coming off from all parts of the body, even from the wings, which process must certainly be the " exception which proves the rule, "for no other insects ever molt after becoming wi
. Elementary entomology. Entomology. THE NERVE-WINGED INSECTS 97. Fig. 124. A stone-fly (Pieronarcys 7-egalis). reduced) (After Newport, from Folsom) (Slightly larger with each successive molt, until the water nymph sheds its skin for the last time, the gills and mouth-parts are left behind, and the winged May- fly comes forth. After flying a short distance it alights and again sheds its skin, a thin layer coming off from all parts of the body, even from the wings, which process must certainly be the " exception which proves the rule, "for no other insects ever molt after becoming winged. The eggs are now deposited by the females either on the surface of the water or on stones beneath the surface, and in a few hours, or at most in a day or two, the adults die. The nymphs live from one to three years, according to the species, and form an important item of the food of fishes, but are othenvise of no economic importance. The stone-flies (order Plecopterd) ^ are quite similar to the May-flies in their general hab- its, but quite unlike them in appearance. The hind-wings are much larger than the fore- wings and are folded beneath them in plaits when at rest. The mouth-parts of the adults are of the biting type, but are often poorly developed. The antennae are rather long and slender, and usually there are two many- jointed cerci extending from the tip of the abdomen. The nymphs live beneath stones in swift-running streams and are from one 1 Yrompieces (plaited), ^ndpieron (wing). (After Comstock). 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
