. Elementary textbook of economic zoology and entomology. Zoology; Insect pests. INSECTS INJURIOUS TO ORCHARD TREES 433 an irregular nest in which the larvae of the bud-moth feed and in which they pupate. Because they attack the buds before they are open they are able to do considerable damage before anything can be done to control them. A careful spraying with arsenate of lead just as the leaves begin to unfold is about the only remedy that can be recom- mended. The Pear Thrips (Euthrips pyri).—For several years this little insect has been the most serious pest with which the orchardists of c
. Elementary textbook of economic zoology and entomology. Zoology; Insect pests. INSECTS INJURIOUS TO ORCHARD TREES 433 an irregular nest in which the larvae of the bud-moth feed and in which they pupate. Because they attack the buds before they are open they are able to do considerable damage before anything can be done to control them. A careful spraying with arsenate of lead just as the leaves begin to unfold is about the only remedy that can be recom- mended. The Pear Thrips (Euthrips pyri).—For several years this little insect has been the most serious pest with which the orchardists of central California have had to contend, and recently it has been discovered that it also occurs in some of the eastern states where it does considerable damage. It at- tacks many kinds of orchard trees, but does particular injury to pears, cherries and prunes. The adult thrips are minute, black-bodied insects with their four long narrow wings fringed with long hairs. They appear early in the spring and soon make their way into the ten- derest part of the bud, often completely destroying it. A little later they begin laying the eggs from which the wingless young thrips hatch. These continue the destructive work begun by the adults. The insect passes the winter in the larval and pupal stages in the ground, the adult issuing very early the following spring. In fighting this pest some insecticide must be used that will penetrate the buds and kill the thrips without injuring the buds. The distillate oil emulsion and tobacco extract (see page 417) have proved most efficient in California. The first spraying must be done as soon as the adult thrips are numerous on the trees, the second application should follow ten days later, and still a third, which is for the larvae, should be given about two weeks after the second. Deep plowing in the fall 28. FIG. 206.—The pear thrips, adult- (Much enlarged; after Moulton.). Please note that these images are extracted from scanned page images
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