. Insect pests of farm, garden and orchard . 249.—Cabbage root infested with maggots. (After Slingerland.) the hard stem above ground. The eggs are about .one twenty-fifth inch long, of a pure white color, which i-enders themeasily seen against the soil by one familiar with them, and are of theshape shown in Fig. 251, having a curious ridge along one side. Theeggs hatch in from three to ten days, averaging five to little maggots at once commence rasping the surface of thetender roots, gradually mine into them, and in three or four weekshave become full grown. The grown maggot is one-
. Insect pests of farm, garden and orchard . 249.—Cabbage root infested with maggots. (After Slingerland.) the hard stem above ground. The eggs are about .one twenty-fifth inch long, of a pure white color, which i-enders themeasily seen against the soil by one familiar with them, and are of theshape shown in Fig. 251, having a curious ridge along one side. Theeggs hatch in from three to ten days, averaging five to little maggots at once commence rasping the surface of thetender roots, gradually mine into them, and in three or four weekshave become full grown. The grown maggot is one-third inch INJURIOUS TO CABBAGE AND CRUCIFEROUS CROPS 349 long, white or yellowish in color, tapering toward the head andobliquely truncate at the tip of the abdomen. From the head apair of strong, black, hook-like, rasping jaws project downward,antl just back of the head on either side is a minute, light brown,fan-like projection (Fig. 253, h), or spiracle, which leads into thebreathing system. The oblique posterior end is surrounded by. Fig. 250.—The cabbage maggot fly {Pegomyia hrassiccB Bouch^), femalegreatly enlarged. (After Slingerland.) twelve rounded tubercles and in the centre are two brownish spira-cles (Fig. 253, a). When done feeding the larva burrows one-halfto one inch under the surface of the soil, and the outerskin graduallyhardens until it forms a firm brown shell, called a puparium,within which the larva transforms to a true pupa. Frequently thepuparia are found in the galleries made by the maggot or in crevicesof the roots. During the summer this stage lasts about two weeks,but in the fall most of the insects remain in this condition over win- 350 INSECT PESTS OF FARM, GARDEN AND ORCHARD
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1915
