ROUNDHEADED APPLE-TREE BORER. 41 



The borers have few insect enemies, but woodpeckers play an im- 

 portant part in holding them in check. The downy woodpecker was 

 observed removing borers from trees. 



No easier and cheaper way of controlling borers was found than 

 the old method of worming trees. The worming should be done as 

 soon as possible after the last eggs of the season have hatched, and 

 should be repeated in the spring following the blossoming time of 

 apple trees. Worming can be done most effectively by two men work- 

 ing together on opposite sides of the tree. In this practice emphasis 

 is placed on the importance of removing all breeding centers within 

 or adjacent to the orchard. 



Paints and various other kinds of tree protectors were used to 

 prevent the adult females from ovipositing in the bark. Nothing of 

 this nature was found that surpassed common white-lead paint in 

 cheapness, ease of application, and effectiveness in controlling the 

 borers. Young apple trees painted once annually for from four to 

 six years showed no injury and the treatment gave a control efficiency 

 of 74.3 per cent. 



Various attempts to kill borers were made by applying to the bark 

 of infested trees penetrating liquids of a poisonous or irritating 

 nature. Nicotine sulphate, kerosene, kerosene emulsion, sodium arse- 

 nate in a miscible-oil carrier, and linseed oil were among the ma- 

 terials tested. None of these was effective on large borers that had 

 penetrated deep into the tree, but most of them killed a considerable 

 percentage of young borers that were still feeding in shallow burrows. 



The beetles feed rather freely upon leaves and the bark of twigs. 

 Tests made indicate that it is possible to kill the beetles by spraying 

 with arsenicals. Sprays for this purpose should be applied to young 

 orchards within 10 days after apple blossoms have disappeared. In 

 bearing orchards what is known as the first codling-moth spray will 

 be effective also against the adults of the roundheaded apple-tree 

 borer. 



LITERATURE CITED. 



(1) Fabricius, J. C. 



1787. Mantissa Insectorum, v. 1, p. 147. 



(2) Say, Thomas. 



1824. Saperda bivittata. In Jour. Acad. Nat. Sci. Phila., v. 3, p. 409. 



(3) Riley, C. V., and Howard, L. O. 



1890. Some of the bred parasitic hymenoptera in the National 

 Museum. In U. S. Dept. Agr., Insect Life, v. 3, p. 57-61. 



(4) Comstock, J. H., and Comstock, A. B. 



1895. A MANUAL, FOR THE STUDY OF INSECTS. 701 p., illUS. 



(5) Smith, J. B. 



1896. Economic Entomology. 473 p., illus. 



(6) Felt, E. P., and Joutel, L. H. 



1904. Monograph of the genus Saperda. N. Y. State Museum Bui. 74. 

 86 p., pi. 



