The following report is the fifth and last of a series dealing with entomological research in the British Possessions in West Africa. The other four have appeared in previous issues of this Bulletin, and in them the aims and methods adopted have been stated in considerable detail. This paper deals mainly with the results of personal observations on the geographical distribution of the various blood-sucking insects in the Gold Coast, made during a tour in that country from November 1912 to June 1913; with these are incorporated, wherever possible, records of previous workers in this line, and consequently the report may be taken as a general summary of entomological work accomplished in this Colony.

The most serious pests that at the present time are threatening the great wool and sheep industry of Australia, are the sheep-maggot flies (blow-flies belonging to the genus Calliphora). Until about ten years ago blown wool on living healthy sheep was unknown, sheep that were worried and torn by dogs were blown, and rams that damaged their heads fighting might have to be dressed and cleaned of maggots, but the bush blow-flies had not until about that date acquired or developed the habit of depositing eggs or living maggots in the soiled or damp fleece of the ordinary station paddock sheep.

In the Entomologists' Monthly Magazine, (2) xxiii, p. 85 (1912), I described as Cacodmus ignotus, sp. nov., a female without locality and compared it with Cacodmus villosus, Stål. The Imperial Bureau of Entomology has lately received from Uganda a pair of a Cacodmus, taken from a bat by Mr. C. C. Gowdey, which differs so little from the specimen described as ignotus, that I consider the two examples to belong to that species.

Monophlebus stebbingi, Green, var. octocaudata, Green, is a large Coccid belonging to the sub-family Monophlebinae. It is found on Mango, Jack Fruit, and species of Ficus, in India, but having, for a Coccid, a long life-history—being but single-brooded—it is rarely a pest. Climatic conditions govern the production of large numbers of individuals, so that outbreaks are irregular, occurring at intervals of a few years.

Since the cessation of the work of the Luangwa Sleeping Sickness Commission in Northern Rhodesia the investigation into the bionomics of Glossina morsitans has been carried on at Ngoa, in the Mpika Division, on the high ground of the Congo-Zambezi watershed. The work included a study of the influence of various bloods on the breeding capabilities of the fly and further investigation of the breeding habits and haunts of the insect in nature. The following notes embody the results of the work during the eight months from January to August, 1913. The climatic conditions during this period are given in Table 1, the temperatures being those of the laboratory.

Mahogany trees are attacked by two caterpillars which inflict a large amount of damage every year. One of these, Heteronygmiu leucogyna, Hmp. (Lymantriidae), eats the leaves, while the other, Mussidia albipartalis, Hmp. (Pyralidae), bores under the bark, causing much deformity of young trees and the formation of corky excrescences, accompanied by the exudation of resin.

In preparing his first synopsis of the African species of Culex (Bull. Ent. Res., ii, pt. 3, Oct. 1911) the writer relied almost entirely upon characters of coloration for the separation of species, and had made no study of the male genital organs; at the same time it was pointed out that the group of species allied to Culex invidiosus required much additional study before their classification could be regarded as satisfactory. It is now possible to give in full the results of further study of the African species of Culex of the pipiens and invidiosus groups. It has been found that, in these groups at least, the species can most readily be separated by means of the male genitalia, and also that one or two names which had previously been sunk as synonyms must in reality stand as good species. In the present contribution figures are given of the male genital organs of eleven species; these, together with the four already illustrated (Bull. Ent. Res., iv, pt. 1, May 1913) comprise all the African Culex with the exception of (1) those with a banded proboscis; (2) those with characteristic leg markings, C. tigripes and C. tipuliformis; (3) C. pruina, which is described below; (4) C. didieri, N.L., and C. pygmaeus, N.L., which the writer is unable to recognise; and (5) those with the pale markings of the abdomen situated towards the apices of the segments. As before, all the figures have been prepared by Mr. A. J. Engel Terzi with very great care and accuracy, and I am much indebted to him for his assistance in this difficult piece of work.

As it is now generally admitted that one or more of the species of fleas occurring on the common rats, Mus rattus and Mus norvegicus, are concerned in the transmission of plague, the study of these fleas has become a matter of the highest importance in connexion with the prevention of the disease. The first point that demands elucidation at the hands of medical entomologists is the identity of the species that is or are responsible. When this point has been satisfactorily determined, attention can be directed to the detailed study of the bionomics of the obnoxious species, as a preliminary to the adoption of appropriate remedial measures. It will be obvious that a sine qua non to a successful attack on the problem is the ability of the investigator to discriminate the various species that he is likely to meet in his researches, and it is the object of the author of these notes to supply a key to the identification of the species of Xenopsylla that occur on rats in India.

Several months' constant traveling in the “proclaimed area” has led the writer to conclude that it contains at least four “primary centres” which harbour tsetse-flies, situated as shown on the map as follows:

No. 1, opposite Rifu, near Patsanjoka Marsh ;

No. 2, W. & S.W. of Kuti Marsh ;

No. 3, at Nyansato near the Chitawa Marsh ; and

No. 4, along and on each side of the Lingadsi River, between Long. 38° 8′ and 34° 13′ E.

The Imperial Bureau of Entomology has recently received from Mr. Ll. Lloyd, Entomologist to the British South Africa Company in Northern Rhodesia, a small Bombyliid fly accompanied by the following letter, dated “Mwengwa, Mumbwa, viâ Broken Hill, N. Rhodesia, November 1, 1913.—I am sending you herewith a specimen of a Dipteron, which I believe to be a parasite of G. morsitans. During July and August of this year I collected about 700 pupae of this Tsetse in nature at Ngoa, in the Mpika Division of Northern Rhodesia. These were kept under observation until September 15th, when I was compelled to travel through fly-free country for a month; they were accordingly closed up in a fly-proof case to avoid escape (in case of possible fracture of one or more of the bottles containing the pupae), and were not examined again until October 18th. On this date one of the bottles, which had contained five Tsetse pupae collected on July 21st, was found to contain:—