. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. 350 ECONOMIC ENTOMOLOGY probably with species of Agropyron as its host plants. A serious pest in the West on wheat and rye (Figs. 232 and 233). Adult.—A shiny black 4-winged fly, J-^ inch long; abdomen with three prominent yellow rings; legs yellow. Female with a short stout horn-like ovipositor. It rests head downward on the stems of grasses, with its wings very close together over the body. June 10- July 10. Eggs.—Minute, white, cylindrical. Larva.—Dull yellowish-white, J^-J^ inch lo
. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. 350 ECONOMIC ENTOMOLOGY probably with species of Agropyron as its host plants. A serious pest in the West on wheat and rye (Figs. 232 and 233). Adult.—A shiny black 4-winged fly, J-^ inch long; abdomen with three prominent yellow rings; legs yellow. Female with a short stout horn-like ovipositor. It rests head downward on the stems of grasses, with its wings very close together over the body. June 10- July 10. Eggs.—Minute, white, cylindrical. Larva.—Dull yellowish-white, J^-J^ inch long; first two segments swollen; end of abdomen with a short blunt projection. Always occurs within the stem. Bores downward in the stem, reaching base. Pig. 233.—Full grown larva of the western wheat-stem saw-fly {Cephus occidentalis) {After Criddle, Bui. 11, Ent. Br. Can.) about August ist and cutting the stems through level with ground; remains all winter in stub until following May. Pupa.—Formed in May in stub inhabited by larva. Control.—I. Plough infested stubble 5 inches deep in fall, with attention at least to worst infested fields. 2. All infested grasses, such as western rye grass, timothy and the prairie grasses next to growing crops should be cut between July loth and August ist. SiRiciD^ (Horn-tails) Pigeon Tremex (Tremex columba Linn.).—Injures elm and maple. Adult.—Female a large 4-winged fly, 2 inches long, with a prominent yellow horn at end of abdomen; head and thorax reddish-black, ab- domen cylindrical, dark brown, with seven yellowish band-like mark- ings; male smaller, without horn. June-August (Fig. 234). Eggs.—Oblong oval, jointed at ends, 3^^o i^ch long. Larva.—^Large, soft, yellowish, cylindrical, with six true legs and a horny point at end of abdomen; boring into wood. Parasitized by. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
