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THE DIPTERA OF SUFFOLK.
THE DIPTERA OF FIRST BY
SUFFOLK.
SUPPLEMENT.
BERNARD S .
HARWOOD.
IT has probably never Struck you that Science fully describes and tabulates in classified sequence those infinite swarms of different midges that you see sitting on walls and palings, on fungi, and dancing in clouds high in the air over water, the fleas that attack so many different mammals and a few birds, the gnats that draw blood from your hand, daddy-long-legs twirling in small companies in the sheltered garden on summer evenings, about hedges in mid-winter and Aying indoors to light in autumn, gad-flies that torment cattle, the metallic-green flies gyrating close over stagnant water, the black-and-yellow hoverers poised still-ly in the air beside your head, bot-flies, dung-flies, bluebottles, carrot-flies, onion-flies, house-flies, lettuce-flies, celeryflies, cheese-mites and gout-flies, with the " ticks " upon horses, cuckoos, martins, swifts, sheep, honey-bees and even bats. Throughout these varied families, Diptera agree among themselves and differ from all other Insects in the possession of only a single wing upon each side of the body. The number of different British species was found in 1901 to be at the least 2577 by Verrall, whose published List (followed, for lack of a later, in this Supplement) is now partially superceded. Actually a conservative computation would put them at well over three thousand. The original " Diptera of Suffolk" (Trans. Norf. Nat. Soc. x, part i, Suppl. pp. 1-180) enumerated 1623 species as known to occur in our county up to 1915 ; the present Supplement raises the total now known here to 1887. Several hundreds more certainly exist, but have not yet been accorded adequate identification, which is necessarily a slow process when treating of such a mass of material. It is just this difficulty, and not the ubiquity of Diptera, that deters Naturalists from collecting " mere flies," beautiful as many are and interesting as is their economy, besides the mosquitoes' and rat-tailed maggots' possession of no small importance to man : that of the house-fly, a species confined to towns, is much over-rated. As far as one can judge at present, there are 2,993 species of Diptera in Britain ; and 1,887 species of Diptera in SufTolk.
In the following additions, only enough details to establish occurrence are given ; many are so abundant that the insertion of every locality would be superfluous.