. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 275 Larva.—A whitish, cylindrical, footless maggot, tapering toward the front, and abruptly terminated behind, where are 12 two-pointed fleshy tubercles and 2 conspicuous reddish-brown spiracles; X^ inch long when full grown (3 to 4 weeks) (Figs. 177 and 178). Pupa.—Puparium in earth, oval, 3-^ inch long, chestnut-brown; 2 weeks in June; Fig. 177.—(a) Caudal
. Class book of economic entomology, with special reference to the economic insects of the northern United States and Canada. Beneficial insects; Insect pests; Insects; Insects. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 275 Larva.—A whitish, cylindrical, footless maggot, tapering toward the front, and abruptly terminated behind, where are 12 two-pointed fleshy tubercles and 2 conspicuous reddish-brown spiracles; X^ inch long when full grown (3 to 4 weeks) (Figs. 177 and 178). Pupa.—Puparium in earth, oval, 3-^ inch long, chestnut-brown; 2 weeks in June; Fig. 177.—(a) Caudal end of cabbage root maggot; (/>) of the imported onion maggot; and (c) of the seed-corn maggot; showing arrangement of fleshy tubercles and central spiracles. All much enlarged. {After Gibson and Treherne, Enl. Bui. 12, Depl. Agric. Ottawa.) Life-history.—Adults appear in May, when cabbages are being set out, and deposit eggs. Maggots hatch in a week and feed on roots for 3 or 4 weeks when they change to pupae within puparia in the soil. In 15 days or so the adults appear in late June and July to lay eggs for a second brood. The number of broods is uncertain, probably three or four, but the later broods do but little harm. Fig. 178.—Cabage root maggot, side view. Enlarged 7 times. {After Gibson and Treherne, Enl. Br. Can.) Control.—Use "single-ply tarred felt" paper disks when young plants are set out; use cheese cloth frames as screens; plant trap-crops; apply white hellebore or pyrethrum either as dust or as solution; use carbolic wash; use corrosive sublimate solution (4 oz to 50 gal. water). In the case of the last three insecticides, treatment should be made when the plants are set out and repeated once a week for 5 weeks. Enemies.—Baryodma ontarionis, a Staphylinid; Cothonaspis gillettei Wash., a Cynipid; and Trombidium spp.—(Consult Bull. 12, Ent. Please note that these images are extracted from scanned page images that may have been di
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsects, bookyear1919
