. Injurious insects : how to recognize and control them . Insect pests; Insect pests. PLAXr LICE ATTACKIJVG THE SOOTS 115 Plant Lice attacking Beet Roots In Washington and Oregon sugar beets sometimes are seriously infested by a plant louse {Pemphigus beta-BoAnc). Affected plants fail to make normal growth, look sickly, and the main root grows spongy. The lice cluster on the smaller rootlets. There are sex'eral generations in the course of a single season, and occasionally winged individuals appear and fl>- to other fields. It is probalile that the species lives normally on some wild plant,
. Injurious insects : how to recognize and control them . Insect pests; Insect pests. PLAXr LICE ATTACKIJVG THE SOOTS 115 Plant Lice attacking Beet Roots In Washington and Oregon sugar beets sometimes are seriously infested by a plant louse {Pemphigus beta-BoAnc). Affected plants fail to make normal growth, look sickly, and the main root grows spongy. The lice cluster on the smaller rootlets. There are sex'eral generations in the course of a single season, and occasionally winged individuals appear and fl>- to other fields. It is probalile that the species lives normally on some wild plant, but the identity of this has not been discovered. In Colorado another species, Tychca brcvicornis Hart., has wrought similar injury. No direct means of control is known for either of these Fig. 79. — ,\dult of Cramhus liitcolcllus Clem. Slightly enlarged. Original. The Sugar-cane Mealy-bug (Pscudococcus calceolaria' ^lask.) In Louisiana the roots, crown, and stalk of sugar cane are attacked by small, degenerate insects whicli work in clusters made conspicuous by a white, cottony secretion. The insect itself is soft bodied, pink, and wingless. Only the males are winged, and they are seldom noticed. For the most part thej' pass the winter on seed cane, but may sur- ^•i^•e also on Johnson grass. When the seed cane is planted in the sjiring, the young are transferred with it to the fields. They may hibernate also on cane stubble. Rotation of crops is the first move towards eradication, combined. 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 O'Kane, Walter Collins, b. 1877. New York : The Macmillan Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsectp, bookyear1912
