. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. 334 ECONOMIC ENTOMOLOGY generation about 43 days and there are probably not more than four or five generations in a season. Life-history.—"The egg is deposited by the female weevil in a cavity formed by eating into a cotton square or boll. The egg hatches in a few days and the footless grub begins to feed, making a larger place for itself as it grows. During the course of its growth the larva sheds its skin at least three times, the third moult being at the formation of the pupa,
. Class book of economic entomology. Insects, Injurious and beneficial. [from old catalog]; Insects; Insects. 334 ECONOMIC ENTOMOLOGY generation about 43 days and there are probably not more than four or five generations in a season. Life-history.—"The egg is deposited by the female weevil in a cavity formed by eating into a cotton square or boll. The egg hatches in a few days and the footless grub begins to feed, making a larger place for itself as it grows. During the course of its growth the larva sheds its skin at least three times, the third moult being at the formation of the pupa, which after a few days sheds its skin, whereupon the trans- formation becomes completed. These immature stages require on the aver- age between 2 and 3 weeks. A fur- FIG . 216 .—Cotton boll-weevil: ther period of feeding equal to about larva at left, pupa at right About o^C-third of the preceding develop- 5 times natural size. {After Hunter.) ... mental period is required to perfect sexual maturity so that reproduction may begin" (Hunter and Pierce). Strawbeny Crown Borer {Tyloderma fragarice Riley). Adult.— A small dark snout-beetle, J:5 inch long; head and thorax black; each wing-cover with 3 black spots. Hibernates. Eggs.—Probably laid in the crown. Larva.—Small white grub mining out interior of the crown; J^ inch long; legless; head yellowish-brown. Matures in August. Pupa.—Formed in the larval cavity. Adults emerge in late summer and fall. Potato Stalk Borer {Trichobaris trinotata Say).—Burrows in the stalks of potatoes. Adult.—A snout-beetle, K inch long, dull black to light grey; three black spots at union of pro thorax and wing-covers; snout curved and as long as prothorax. Front of prothorax orange-yellow. Hibernates in burrows in the old stalk. Eggs.—Small, oval, pearly white; laid singly in punctures in stalks. Larva.—Yellowish-white; head light brown; legless; % inch long. Burrows in the stalks. Pupa.—At first yellowish-white, later dull b
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
