. Insect life; an introduction to nature study and a guide for teachers, students and others interested in out-of-door life. Entomology; Nature study. Fig. lEo.—a gall-fly. galls which are much more abundant than those of the gall-flies ; these are the galls made by plant-lice and by mites. The galls produced by plant-lice, and also those produced by mites, differ from the galls of the gall-flies in tliat each gall has an open mouth. The conical galls which are so common on the leaves of witch- hazel (Fig. 181) are good illustrations of this type of gall. These galls project from the upper sid
. Insect life; an introduction to nature study and a guide for teachers, students and others interested in out-of-door life. Entomology; Nature study. Fig. lEo.—a gall-fly. galls which are much more abundant than those of the gall-flies ; these are the galls made by plant-lice and by mites. The galls produced by plant-lice, and also those produced by mites, differ from the galls of the gall-flies in tliat each gall has an open mouth. The conical galls which are so common on the leaves of witch- hazel (Fig. 181) are good illustrations of this type of gall. These galls project from the upper side of the leaf, but each has an opening on the lower side of the leaf. The plant-louse that produces this gall is an agamic female (see page 177); when this female is mature, she gives birth to numerous young, which escape from the mouth of the gall, scatter over the leaf, and each in turn produces a gall. In most localities there are so many kinds of galls that it would be unwise for a student to attempt to study them all. A better plan is to select some one species or genus of trees and to study the galls made on these trees by one family of insects. Thus, if oaks occur in the locality, a good subject is the oak galls. Fig. 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 Comstock, John Henry, 1849-1931; Comstock, Anna Botsford, 1854-1930. New York, D. Appleton and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomol, bookyear1901
