1 SEPTEMBER 1923, Page 13

BIRD PARASITES.

[To the Editor of the SPECTATOR.] SIR,—In his interesting letter, Mr. C. W. Early asks whether swifts are usually troubled with large insect pests. Gilbert White says : "The hirundines " (he includes the swift in this family) "alone seem to be annoyed with dipterous insects, which infest every species, and arc so large, in propor- tion to themselves, that they mast be extremely irksome and injurious to them. These are the irippoboscae hirundittes (craterina hirundines of Olfers), with narrow subulated wings, abounding in every nest, and are hatched by the warmth of the bird's own body during incubation and erawl about under its feathers." Mr. Early mentions that the swifts left Witney this year at the beginning of the second week in August. The Brighton swifts went at the same time.—I am, Sir, &c., 83 Upper North Street, Brighton. A. CAMERON SHORE.