. Eastern forest insects . COURTESY CONN. AGR. EXPT. STA. Figure 42.—Adults, larvae, and pupae of the imported willow leaf beetle, Plagiodera versicolora. Note skeletonization of leaves by larvae and holes eaten in leaves by adults. farther southward. Heavily infested trees may become entirely brown as early as mid-June. A considerable degree of natural control is exerted by the imported pupal parasite, Schizonotas sieboldi (Ratzeburg) (203). Extremely cold winters are also fatal to adults not well protected. Systena marginalis (111.) feeds on oak in the midwest and on cypress in northern Flor
. Eastern forest insects . COURTESY CONN. AGR. EXPT. STA. Figure 42.—Adults, larvae, and pupae of the imported willow leaf beetle, Plagiodera versicolora. Note skeletonization of leaves by larvae and holes eaten in leaves by adults. farther southward. Heavily infested trees may become entirely brown as early as mid-June. A considerable degree of natural control is exerted by the imported pupal parasite, Schizonotas sieboldi (Ratzeburg) (203). Extremely cold winters are also fatal to adults not well protected. Systena marginalis (111.) feeds on oak in the midwest and on cypress in northern Florida and southern Georgia. The adult is dull pale yellow in color except for two black lines along the front margin of the elytra and a single black line along the hind margin. The wing covers are densely and coarsely punctate. Adults are present from mid-June to late August and feed by gouging out linear-shaped punctures in the leaves. This usually causes part or all of a cypress leaflet to turn red and die. The beetles occur in large swarms which tend to move about, spending only one to three days in any one place. A single swarm may encompass more than a dozen trees. Zengophora scutellaris Suffr., an introduced species, feeds on cottonwood and other poplars from New York and New Jersey to Montana and New Mexico. The adult is about 4 mm. long. The head, prothorax, and legs are yellow; the tarsal claws are toothed; there is a prominent tubercle on each side of the prothorax; the elytra are coarsely punctate; and the abdomen is black. The re- mainder of the body is yellow. Adults feed by skeletonizing the lower surfaces of leaves. The larvae feed singly in the soft inner tissues, chiefly against the upper surface of the leaf, making large black blotch mines. When they become full-grown they vacate their mines and drop to and enter the ground. Here they construct cells several inches below the surface in which to pupate. Trees heavily fed on by both larvae and adults may be com
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectforestinsects
