CIVILIZATION AND INSECTS SMITH 261 



apple worm, and quince curculio; from wild crab came the round- 

 headed apple tree borer and the light apple redbug. These forms 

 thrive among the acres of plum, cherry, prune, and apple orchards 

 developed as a consequence of modern agriculture. 



Apparently the famous blueberry of the maritime provinces of 

 Canada and New England has an increasing list of insect enemies. 

 This plant, largely uncultivated, forms the basis of a million-dollar 

 industry in Maine. A recent study of this plant added, over the lists 

 of previous w^riters, 80 insect pests depending on the blueberry for 

 food.^ 



The apple curculio {Tachypferellus quadrigibhus Say), a native 

 insect which fed on hawthorne and wild crabs, has lately become a 

 severe pest of apples in northeast Kansas, and the greater the neglect 

 or poorer the orchard sanitation, the worse the damage. Another 

 species of this genus has lately been noted to be a cherry pest in 

 Colorado.® 



The walnut husk maggots {Rhagoletis juglandis Cress.) were until 

 recently innocuous dwellers under the hulls of the common black wal- 

 nut and a few other similar hosts. While they still occur on their 

 wild hosts, these insects in recent years have appeared in Arizona and 

 California, where they have produced a problem for the English 

 walnut growers. As a result of their feeding in the hulls of English 

 walnuts, the nuts are stained and rendered less marketable. 



The plum gouger was an unimportant feeder on wild plums, but 

 has increased under modern orchard conditions. The grape berry 

 moth, grape flea beetle, and the grape root worm, all of which fed 

 on wild grapes, have found expansive opportunities very favorable 

 in modern vineyards. 



The beet leafhopper, during the summer, forsakes its wild food 

 plants in the foothills or desert for the beet fields. After spreading 

 havoc in the beet fields, some of these insects return to their wild food 

 plants in the foothills. A recent increase in curlytop damage to beets 

 in Utah is said to be due to new breeding grounds of favorable host 

 plants on thousands of acres of abandoned dry farms." This situa- 

 tion raises the question of what will happen when man begins to 

 abandon agricultural lands if the soils are depleted or the price of the 

 products makes their continued cultivation unprofitable. Such pests 

 as the beet leafhopper and grasshoppers are likely to be favored by 

 that step. 



' Phipps, C. R. Blueberry and huckleberrj' insects. Maine Agr. Exp. Sta. Bull. 356, 

 pp. 107-232, figs. 17-24, 1930. 



» List, Geo. M. A cherry pest in Colorado. Colorado Agr. Exp. Sta. Bull. 385, 106 pp., 

 1932. 



» Knowlton, Geo. F. The beet leafhopper in northern Utah. Utah Agr. Exp. Sta. 

 Tech. Bull. 234, 64 pp., 1932. 



