. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 24 THE WOOLLY APPLE APHIS. {Srhizo7vura lanigerii Hausmann—figs. 14 and 15.) One often notices on the trunk, or larger branches of the apple. Fig. U.—Schizovrurahini(ifm: a, agamic female; 6, larva; r. pupa; f7, winged female. (Marlatt.) small, bluish-white, llocculent patches of a woolly sul^stance, which indicate the presence of this insect. This cotton A' substance is a wax-like excretion ciing-ing- to the posterior parts of a small, reddish-brown wingless aphis. It is not, however, this form on the trunks tha
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 24 THE WOOLLY APPLE APHIS. {Srhizo7vura lanigerii Hausmann—figs. 14 and 15.) One often notices on the trunk, or larger branches of the apple. Fig. U.—Schizovrurahini(ifm: a, agamic female; 6, larva; r. pupa; f7, winged female. (Marlatt.) small, bluish-white, llocculent patches of a woolly sul^stance, which indicate the presence of this insect. This cotton A' substance is a wax-like excretion ciing-ing- to the posterior parts of a small, reddish-brown wingless aphis. It is not, however, this form on the trunks that causes injury. This aerial form is but the indication that there are other speci- mens, under the ground and feeding on the roots of the tree. It is the latter form that seriously affects the vitality of the tree. Upon the trunk the lice often cause a roughening of the bark, especially on the new growth around sears made by prun- ing. On the roots the lice cause hard and large knots, which eventu- ally produce a '"club-footed" con- dition of the roots. Such trees usually show their weakness by the fewer and dullei- colored leaves. The woolly aphis is practically confined to the apple, but there are a few varieties, such as the Northern Spy, that appear to be imnume against its attacks. The lice com-. 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 United States. Bureau of Entomology. Washington : G. P. O.
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