Peles (p. 92) is proposed[49] by Mr. Bangs as a new genus for Caprimulgus binotatus Bp.—A review of the South American Short-eared Owls[50] leads him to recognize three neotropical races. These are Asio f. breviauris (Schlegel) from southern South America; A. f. bogotensis Chapman, from the Bogota Savanna, and A. f. sanfordi (p. 97) subsp. nov., from the Falkland Islands.
Another paper[51] deals with the races of Dendroica vitellina Cory, and a new form is described from Swan Island which Mr. Bangs names D. v. nelsoni (p. 494). It is somewhat intermediate between the other forms—the typical race of Grand Cayman and D. v. crawfordi Nicoll, from Little Cayman and Cayman Brac.—W. S.
Economic Ornithology in Recent Entomological Publications. —Items pertaining to this subject continue to accumulate slowly. Those on hand pertain to the following insects:
Larch bark-beetles and borers.—In a general account of insects affecting the larch in Erie County, N. Y., is the following interesting information, relating to the work of woodpeckers.[52]
“The work of woodpeckers is much in evidence and seems to be an efficient agency in reducing to some extent the numbers of the brood of several of the more numerous bark-boring insects. The birds seem to work in two ways—first by making small conical holes through the bark into the sapwood to obtain the larvæ of the larger species of beetles which have gone there to hibernate or to pupate, and secondly by removing practically all of the bark on large areas of the trunk to uncover the brood (larvæ, pupæ and young adults) of the bark beetles.
“In some cases this work reached an unusual degree of efficiency. For instance one particular tree forty or fifty feet high and about 14 inches in diameter, had had nearly all of the bark removed from the ground to the very tip. This tree had been heavily infested with Dendroctonus simplex, Polygraphus rufipennis and other borers, but only a small per cent of the original infestation had survived the woodpeckers’ thorough search for food. Of course all of the infested trees had not been so thoroughly gone over by the birds and a number of such trees had apparently not been found by them at all. However, it is safe to say that the woodpeckers were an efficient force, working toward the return of the normal balance of nature which had been upset by the breeding of certain species of insects above the danger level, due to the girdling, season after season, of a number of the larches by farmers. It is not believed that the woodpeckers will be able unaided to reduce the numbers below the danger level, as long as more trees are girdled each year, but should this practice cease it is possible that they would be able eventually to obtain the upper hand and that conditions would return to normal.”
Lepidopterous root-borers.—The grape root-borer (Memythrus polistiformis) for which no parasites are known was seen to be eaten in the adult stage by the Crested Flycatcher (Myiarchus crinitus).[53] Two other Flycatchers, the Kingbird and Phoebe, are recorded as enemies of both the greater and lesser peach-tree borers (Sannenoidea exitiosa and Synanthedon pictipes).[54] All of these insects are not only seriously destructive, but from their secluded habits in the larval stage, have few parasite enemies and are difficult to control by man. They belong to a family of moths all of which in the adult condition more or less closely mimic wasps and other hymenoptera and which have been supposed, probably mistakenly, to derive some advantage from this resemblance, in the way of immunity from predatory enemies.
Cankerworms.—An investigation of the relation of birds to cankerworms near Lawrence, Kansas, has had the same result as those made by several previous students, among whom were Riley, Forbes and Forbush. The following summary of the matter is quoted and abstracted from a report[55] by Mr. Walter H. Wellhouse.
“Next to unfavorable weather, the birds are the most important natural enemies of the cankerworms. Probably no insect is a favorite food of more species of birds than the cankerworm larva. It lives exposed on the outside of twigs and leaves where the birds can easily secure it, and is without distasteful hairs or spines on its integument. The English Sparrow, which is said to have been imported into America to check the ravages of this insect, is no doubt our most efficient cankerworm eater in the cities. We have watched these much-despised birds picking larvæ from the elms at all hours of the day from early morning to twilight, and even during rains. The Robin is also an efficient destroyer of cankerworms, especially of the moths which are found at the base of the tree. The writer has seen flocks of Bronzed Grackles alight in the tall elms in Lawrence, and, moving from branch to branch, noisily devour great numbers of larvæ. Having exhausted the supply on one tree they moved in concert to another tree to continue the feast.
“Many of the more timid birds which are not found in the cities so commonly as the English Sparrow and Robin are just as efficient enemies in the country.