CONTROL OF INSECT PESTS McATEE 433 



were examined in May, 1907, with 19 per cent alive, 66 per cent having been 

 killed by birds, 6 per cent by disease, and 9 per cent by cold. It is quite 

 evident that the birds, particularly the downy woodpeckers and the nuthatches, 

 are the most important enemies of the codling moth in New England, and that 

 they should be given every protection and attracted to the orchard in every 

 way possible. 



One instance is at hand also in which a California orchard ap- 

 parently was freed of codlinn; moths by red-shafted flickers. 



In relation to other Tortricidse, Prof. W. S. Regan has .stated that 

 blackbirds do much good by feeding on the fruit-tree leaf-roller in 

 Montana,^" and jNIr. E. H. Forbiish records the local suppression of 

 a spruce moth in Maine by warblers.^' The spruce budworm {Tor- 

 trix fumiferana)^ a prime pest of firs and spruce, also has very effec- 

 tive bird enemies. In times of great abundance of the insect in New 

 Brunswick birds were observed to take over 13 per cent of the broods, 

 and under more normal conditions in British Columbia more than 

 38 per cent.^^ " In this case," says Doctor Tothill, " the natural 

 checks brought about a reduction of the insect before any trees were 

 killed, and in the following year the outbreak subsided entirely, due 

 to continued activity of the birds against the smaller number of 

 larvae." 



The remaining families of Lepidoptera for which we have records 

 of effective control by birds are the Yponomeutidse and the Elachis- 

 tidse. One of the former group, the diamond-back moth {PluteUa 

 Tnaculipennis) is a cabbage pest, and Mr. J. L. Harris, of Minnesota, 

 testifies that this insect was entirely extirpated from his patch by 

 blackbirds. In the Elachistida^, a forest pest again, the larch case- 

 bearer {Coleophora laricella) has effective enemies among the birds. 

 In fact, Mr. A. B. Baird says, of his New Brunswick observations, 

 " Birds were among the chief factors in controlling this insect." 

 The percentage of larvae about clearings taken by birds was esti- 

 mated at 75 per cent and for the area in general 25 per cent.^^ 



HYMENOPTERA (ANTS, BEES, AND WASPS) 



In this order ants attract attention b}' their combined destructive- 

 ness and abundance and thus afford opportunity for observations on 

 control by birds similar to those here recorded for the other orders. 

 Flickers often are observed to suppress small colonies of ants, and 

 Mr. J. D. Mitchell and Dr. W. Dwight Pierce have recorded the 

 destruction of an entire swarm of agricultural ants in Texas by 

 jackdaws.*" Another instance of bird control of Hymenoptera is 



»» Circ. 109, Mont. Agr. Exp. Sta., 1922, p. 12. 



"Bull. 9, Mass. Dept. Asjr., 1921, p. 44. 



3s Tothill, .Tolin D., rroc. Ac.idian Ent. Soc. 8 (1922) 192.1, pp. 174-17G. 



™rrof. Acadian Ent. .Soc. S (1922) 1923. pp. 169-170. 



*" Proc. Ent. Soc. Wash. 14, No. 2, June 1012, p. 72. 



