The tsetse-fly investigation now in progress in the Northern Provinces of Nigeria is an outcome of the proposal of the Imperial Bureau of Entomology that tsetse-fly research in Africa should be put on a more organised basis. For various reasons it is not yet practicable to inaugurate this work with funds contributed by the various Colonies interested in the problem, but the suggestion so met with the whole-hearted approval of His Excellency Sir Hugh Clifford, G.C.M.G., Governor of Nigeria, and of Dr. T. E. Rice, Director of Medical Services, that it was decided to commence such an investigation at once. The helpful interest of these gentlemen has greatly aided the commencement of the work. At present the only investigators engaged are the authors of this report, the first of whom began work in July 1921 and was joined by the other in September of that year.

♀. Head clothed almost entirely with broad flat scales, though there are a very few narrow curved ones and a few upright forked ones on the nape. Scales at the back of the head mostly light ochreous; a rather broad creamy mid-dorsal stripe, and a conspicuous silvery margin to the eyes; remaining scales on upper part of head forming two large but irregular patches of black; another small black patch low down among the creamy scales on each side. Clypeus bare, dark brown. Eyes well separated. Orbital bristles dark brown. Proboscis blackish, slender, slightly longer than the front femora. Palpi fully one-fourth as long as the proboscis, blackish, with the usual conspicuous silvery apical patch. Tori blackish, with a large patch of silvery-white scales. Thorax with the integument uniformly black. Mesonotum clothed mainly with rather large and coarse, dull brown, narrow, curved scales, those surrounding the ante-scutellar space golden-brown, but scarcely any broader than the others, and not forming definite lines; no mid-dorsal golden line; a small patch of board flat silvery scales in the middle of the front margin, and a small patch of narrower scales in front of the root of each wing; a pair of large crescent-shaped patches of broadly crescent-patches of broadly crescent-shaped silvery-white scales in the anterior half. Scutellum with the median and lateral bodies lobes completely clothed with silvery scales. Prothoracic lobes, pro-epimera bristles, and a large part of the pleurae clothed with silvery-white scales. About five pro-epimeral bristles, and about five post-spiracular; no lower mesepimeral. Abdomen clothed mostly with purplish-black scales; the first tergite, and a basal band on each of tergite, 2–7, creamy white; all tergites with large silvery basal lateral spots, and sternites with silvery basal bands. Eighth segment rather prominent; cerci very short. Legs rather slender. Front femora almost entirely black; mid fermora black except for a small white spot on the anterior side just beyond the middle, and a rather conspicuous silvery-white tip; hind femora all white on the basal fourth, the outer side silvery-white to a little beyond the middle and also rather broadly at the tip. Front and middle tibiae with a small white spot at the base beneath, hind tibiae entirely black. Front and middle tarsi black, with narrow white rings at the bases of the first two segments; hind tarsi with rather narrow white rings at the bases of the first three segments, fourth segment white except for the extreme tip, fifth all black. Front and middle claws toothed; hind simple. Wings normal, the scales ligulate and rather dense. Wing-length 4 mm.

♂. Head: Eyes closely contiguous, leaving a small, well-raised, brownishgrey dusted ocellar tubercle at vertex with rather large, shining brown ocelli and a few short pale hairs. Large facets of eyes pale brownish-yellow, the small facets nearly black. Frontal triangle extremely small, yellowish-grey dusted. Antennae with first joint moderately long and thick, broadly cylindrical, tapering at base; second joint shorter and narrower than first; subcylindrical, both with short black, stiff hairs; third joint of normal shape, bare, a little longer than first and second together, with five annulations, the last four being black, basal annulation and first and second joints wholly orange. Whole underside of head shining honey-yellow, a medium-sized yellow-dusted space on each side of face contiguous to eye margin. Proboscis and palpi a little deeper coloured, former with labella black. Occiput ash-grey dusted, lower part yellowish with a little pale soft hair.

Last July (1922) a species of beetle, kindly identified by Dr. G. A. K. Marshall as the Tiger beetle, Cicindela octoguttata, F., a common Tropical African species, was observed to prey on mosquito larvae at Accra, in the Gold Coast. As this habit of the beetle does not appear to have been previously observed, and as it is perhaps remarkable that it should prey on such entirely aquatic insects as mosquito larvae, the following brief note may prove of interest.

In the course of my investigation of the serious pest of palms, Oryctes rhinoceros, it was observed that a great proportion of the larvae work their way several inches below the floor of the manure pit in which they thrive, for pupation; and it occurred to the writer that attempts should be made to prevent the return journey by the insects as adults. Now the larvae and adults are of about equal girth, but as the former are soft-bodied they can squeeze themselves through holes which are impassable for the rigid-bodied adult. A sheet of expanded metal with meshes 12 by 24 mm. will let the larvae through but not the adults, and therefore should prevent the escape of beetles from manure pits in which the floor has been carefully covered with this metal. How far the idea will be of practical application in the control of the pest under the varying conditions in which manure is stored remains to be seen, but this preliminary note is written to drew attention not to any remedy but to the principle itself, which is important and has a wider application than to the insect from the study of which it was first derived. It has been found, for example, that it operates in the case of flies also, the holes through which the maggots may be able to pass being impassable for the adults. In the case of the house-fly a perforated zinc sheet will let the maggots through, but not the adults, and a trap is under trial in which the flies are attracted to suitable material and the maggots resulting from oviposition have to pass for pupation through a perforated zinc sheet into a chamber from which the flies cannot escape. The success of this trap as well as of the lines of attack now opened up against Oryctes rhinoceros remains to be seen, but the principle is, I believe, of sufficient importance for early attention to be drawn to it in the pages of this journal.

In this paper short descriptions of several new species of the genus Finlaya, Theo., are given, together with a note on Finlaya assamensis (Theo.). These will be dealt with more fully in another paper which is now in preparation, and which will include synoptic tables, photographs, and drawings of the male hypopygia, as far as possible, of all the species of this genus found in India up to the present; this paper will be published in the Indian Journal of Medical Research as soon as possible. Through the kindness of Dr. N. Annandale I have been able to examine a number of type specimens in the Indian Museum collection, and to obtain the loan of a few, of which photographs have been prepared.

In this paper are described the early stages of a few more West African mosquitos. All the specimens were collected in the Gold Coast, and most of them at Accra or in the neighbourhood of that town. In drawing up descriptions of larvae we have followed the usual plan, but in the case of the setae on the head have given, when necessary, the terms employed by W. D. Lang in his admirable handbook of British Mosquitos. In drawing up descriptions of pupae we have used the terms (and lettering) suggested by one of us in his account of the chaetotaxy of the pupa of Stegomyia fasciata (Aëdes argenteus).* We have once more to express our indebtedness to Dr. G. A. K. Marshall, of the Imperial Bureau of Entomology, and to Mr. F. W. Edwards, of the British Museum, for help and advice and for the identification of species, and to Mr. A. J. Engel Terzi for his skilful execution of the figures.

In 1913 Major Austen asked me whether it would not be possible to reproduce artificially the conditions which tempt the female Glossina palpalis to deposit its larvae (Report of Departmental Committee of Colonial Office on Sleeping Sickness, June 1914. Questions 1420, 1421) I replied that I thought it would, and early in 1914, on my return to Uganda, commenced a preliminary experiment to test the possibility of reducing the numbers of palpalis by providing highly attractive artificial shelters under which larvae would be deposited in numbers, and where the pupae could be collected easily and regularly destroyed. These preliminary investigations were described in my Fifth Report on the bionomics of palpalis published in the Reports of the Royal Society's Sleeping Sickness Commission (No. xvii), and it was claimed that these results were sufficiently promising to make the method worth attention and further experimental trial. Before I went on long leave in 1919 I had arranged for such a trial to be carried out in my absence, but the experiment came to an end from causes beyond my control before a satisfactory result could be obtained either confirming or contradicting the claims made for the method.

Head 0·83 mm. long, shiny orange-yellow, with the clypeus and the adjoining portion of the frons shiny black. Eyes black, prominent, extending laterally beyond the anterior lateral margins of the pronotum. Rostrum brownish black, extending to, but not surpassing, the posterior coxae; lengths of the joints: first 0·53 mm., second 0·76 mm., third 0·4 mm., and fourth 0·6 mm. Antennae brownish black, the third and fourth joints somewhat paler; first joint slightly incrassated, length 0·83 mm., second 2·0 mm., third 1·83 mm., fourth 1 mm. Pronotum shiny orange-yellow, posteriorly somewhat suffered with dark brown; length in middle 1·4 mm., breadth at anterior margin 0·8 mm., at posterior margin 2·0 mm.; sides straight, posterior margin moderately convex. Scutellum shiny black, finely rugosely punctate and regularly covered with pale depressed hairs; length in the middle 1·3 mm. Corium and cuneus similar in colour and pilosity to the scutellum; membrane dark smoky brown, veins shiny black, passing the apex of the abdomen. Sternum: mesostethium and metastethium black, the metastethial orifices and the surrounding areas very pale yellow: undersides of abdomen shiny black, covered with very fine pale hairs. Legs: coaxae blackish brown; femora dirty orange-yellow, suffused at base and apex with brown; tibiae dark brown, armed with fine black spines; tarsi black, strongly pilose.

Orthopodomyia arboricollis was described under the name of Culex arboricollis by d'Emmerez de Charmoy, from adults reared by him from larvae that were found by Sir Ronald Ross, K.C.B., F.R.S., in a tree-hole at Vacoas. Mr. d'Emmerez tells us that these adults were the only ones he has seen in his long experience in Mauritius, and the species so far is recorded from this island only. Mr. F. W. Edwards, after examination of the types in the collections at the Liverpool School of Tropical Medicine, has recently correctly assigned the insect to the genus Orthopodomyia.

During the past summer Mr. F. W. Urich, Government Entomologist, Trinidad, B.W.I., succeeded in rearing a number of small Chalcids from larvae of a thrips in the prepupal stage. The following description is based on part of this material.

Sugar-cane is the principal crop of British Guiana, and during the year 1921 there were 65,870 acres under cultivation. This area yielded 110,985 tons of sugar and 2,228,164 gallons of rum, the value of the crop being about $10,355,000 (£2,157,200).

The collection was received through the Deputy Director of Agriculture (Research) and contained the following species, collected by the Assistant Entomologist, Rao Saheb Y. Ramachandra Rao:—

Pseudococcus citri (Risso), on grape vine.

Asterolecanium phoenicis, sp. n., on date palm.