The blood-sucking flies here dealt with were collected in Hong Kong by Dr. H. Macfarlane, the Government Bacteriologist, and Mr. Adam Gibson, M.R.C.V.S., the Colonial Veterinary Surgeon, and were forwarded by them to the Imperial Bureau of Entomology. The collection comprises not many species, but long series of several species, such as Tabanus rubidus, Wied., T. albimedius, Wlk., T. sanguinarius, Wlk., and T. mandarinus, Schiner.

There are certain smells remarkably attractive to male flies of the genus Dacus and by the employment of these smells the movements of the flies can to a great extent be controlled, in any given direction. The reaction is strictly confined to the male sex, and different species exhibit a variation as regards the smell which is most attractive to them. It is uncertain whether the females emit similar smells; on the whole improbable.

Three of the commoner species of the flies (D. diversus, ferrugineus and zonatus) normally breed respectively in (1) anthers of Cucurbitaceae, (2) fruits of Solanaceae and mango, and (3) peach, guava, mango and other fruits. D. diversus (1) is most strongly attracted by iso-eugenol, zonatus (3) by methyl-eugenol, and ferrugineus (2) by both methyl and iso-eugenol. The smells of these substances have not yet been identified with those of the plants which constitute the normal breeding-places, but male flies have been found attracted to mango, Papaya, a Cycad, and Colocasia. plants with a very characteristic smell similar to that of eugenol-derivatives. Females have never been seen to frequent these plants or to breed in them, but more extended observation is required on this point before it can be definitely said that they never do so. The males give the impression that they might visit these plants for food, for they suck the surface of the flowers, though they do not seem to exhibit any very particular avidity. One species (ferrugineus?) has been bred from a Eugenia at Bangalore.

Three explanations suggest themselves:.—

(a) The smell is a direct sexual guiding smell emitted by the female.

But young crushed females did not attract males.

(b) The smell is not emitted by the female, but may be termed an “indirect” sexual guide to the plants where the females are accustomed to congregate for breeding purposes.

Under these circumstances it is difficult to see why females should not also be attracted by the odoriferous chemicals.

(c) The smell is a food-smell.

It must then be a food attractive only to males.

Two other species of fruit-flies, D. caudatus (breeding in fruits of Cucurbitaceae) and an unidentified species, were captured by means of an amyl-vanillin solution and of eugenol respectively. The rarity of the flies and the small numbers caught (four and one) make it advisable, however, to postpone detailed comment on these two cases, and future work may give more definite information as to their chemical relations. No substance attractive to male cucurbitae has been found.

All the observations described were made at the Pusa Research Institute, India.

Inasmuch as Phlebotomus verrucarum, Towns., has been seriously questioned as the vective agent of verruga in an important memoir recently issued,* the writer feels it incumbent upon him to answer the objections raised, as well as to reply to the various speculations put forward in the same work relating to the subject of the insect transmission of the disease.

♀.—Head and body shining black, with slight metallic reflections as follows:—Genae dark green, purplish and carmine towards the eye; upper surface of abdomen, in some lights, very faint dark green; tegulae like the rest of the thorax. Antennae dark brown, almost black on scape, pedicel and base of funicle; last two funicular joints lighter; club entirely pale. Wings almost hyaline, but with a faint tinge of yellow, and slightly browned on the submarginal towards the costa, as well as on the punctiform marginal vein. Legs entirely pale yellowish; the posterior femora a little browner on the dorsal edge towards the apex.

♀ The entire integument of the head and body metallic and shagreened, or highly raised reticulate; the abdominal tergites being a little smoother. Head in profile triangular, from above somewhat thin, shallowly concave across the frons, rounded behind the eyes from vertex to genae; but medianly, behind the raised ocellar traingle, there is an inconspicuous ridge before the occiput; from in front, exceedingly wide, the scrobes set close together in the middle of the face, well above the base line of the bare eyes. Labrum long, spade-shaped, conspicuous; mandibles similar, bidentate, a little asymmetrical. Antenna thirteen-jointed, with simple cylindrical joints; the divisions of the club indistinct. Thorax much swollen; pronotum almost concealed behind the head; nearly separated into two tergites; prosternum posteriorly truncated, triangular; mesonotum with the parapsidal furrows fine and hardly traceable. Axillae quadrate, touching, or only separated narrowly (?). Scutellum with a transverse suture before the unarmed, rounded apex; mesopleural femoral furrow well-marked, and the prepectus rather large. Wings: forewings with the post-marginal almost obsolete; radius very short, with a terminal group of clear cells instead of the usual linear arrangement. Hind wings with the submarginal cell long and wide. Legs: fore coxae long; hind tibiae bicalcarate without apical comb. Abdomen sessile or practically so; broad, depressed and broadly concave above; very shortly carinate (basal one-third) below. The first tergite (which with ii. and iii. is posteriorly, medianly notched), covers threefourths of the surface; tergite ii. reaches the edge; the third is on the edge; while tergites iv., v., vi., vii. are all ventral in position. The ovipositor is broad, stout, with strong teeth on the needles and central piece.