A small belt of Glossina morsitans has been studied for four and a half consecutive years.

The community has been observed during the period of its prosperity when the population increased and attempted to colonise unsuitable country ; the outward spread of the fly was checked by insuperable natural barriers, and a period intervened when the fly advance had come to a standstill ; the tsetse were observed in their attempt to breed and establish themselves in an area that could only temporarily suffice their needs.

This optimum period was brought to a sudden close by the advent of unfavourable climatic conditions. The effort made by the community to establish a habitat in an unsuitable type of bush was frustrated by the almost complete extermination of its population. The country which had been colonised by the tsetse was depopulated, and once more was limited to a small population that had survived in the true and permanent habitats. A long period followed in which the tsetse were seen to make a slow but steady recovery. The investigation closes with recovery assured, but the community still too depleted in numbers to attempt further expansion for a considerable time.

Throughout this rise and fall in the fortunes of the fly community, the size of the tsetse population has been seen to fluctuate seasonally with the annual variations in the climate.

The Red-billed Oxpecker, or Tick-bird, is the East African representative of a genus that has always excited interest by reason of the peculiar feeding habits of its members. They obtain the whole of their food on the bodies of the larger Herbivora, and their abnormally sharp claws permit them to travel in any direction and to visit every spot on the bodies of their hosts. It is obvious that to stock-owners birds of these habits must be of economic importance, but veterinary, ornithological and entomological literature alike have failed to provide any record of an investigation of their food.

In the absence of published data application was made to various authorities for their opinions and for any detailed information they might have. Astonishingly diverse replies were given. The head of a veterinary laboratory in one of the East African dependencies wrote as follows : “ I believe they do pick off ticks, although I doubt if they eat these ; their object being to find a wound. When they have succeeded they feed on the exposed raw tissue.” Another local veterinary authority remarked : “ They cause a great deal of damage through the sores they produce in stock.” A gamewarden said : “ I always regarded the oxpecker as an unmitigated nuisance and pest. The prevalent idea that this bird frees domestic stock of ticks appears to be entirely erroneous.… These birds feed mainly on the raw tissue of open wounds and it is by their action that the open wounds usually occur.” Other observers of wide experience are less downright.

1. Tsetse-flies have been divided into four stages of hunger by their external appearance. These stages have been correlated with the internal appearance determined by dissection. It was found that the fat-bodies became maximally developed shortly after a meal, and thereafter diminished rapidly in bulk. Hunger of flies in samples is expressed as the Mean Hunger Stage (M.H.S.).

2. Flies in different stages of hunger showed different behaviour in the field. Thus hungry flies usually attacked head-upwards, replete flies, if attacking, tending to adopt a head-down attitude. Most replete flies preferred to settle on the ground, or on objects other than the members of the catching party. Hungry flies were the most persistent followers.

3. The true habitats and feeding-grounds of Glossina morsitans, G. swynnertoni, and G. palpalis are described, so far as they are known to the writer.

4. Confirmation of the feeding-ground theory was obtained for G. swynnertoni by an analysis of the to-and-fro movements of marked flies.

5. Considerable independent movement of flies was shown to occur in the absence of carriage on man or game. Some flies under such conditions travelled over 2 miles in 3 hours.

The application of an undiluted paraffin extract of pyrethrum for controlling Antestia and Lygus simonyi on coffee trees is described.

(1) The spray is applied with a small hand “ atomiser,” using 20 cc. of extract to a tree, and spraying under a cloth cover.

(2) Tables are given with detailed figures in which the different methods of application may be compared. The kill of Antestia brought down by the most favourable method is 99%.

(3) The proportion of insects brought down by the spray is in the neighbourhood of 96%. It appears that in practice a kill not much below 95% should be possible.

(4) Of the Lygus on trees sprayed, 99% were brought down and the kill of these was complete.

(5) The method is a dual control for Antestia and Lygus, and examples are given of trees sprayed when both these insects were present in serious numbers.

(6) An experimental field spraying against Lygus is described in detail. It was shown that the numbers of Lygus could be kept below two to a tree by this spraying, and the proportion of fruit set on the sprayed block to that on the control was 3 : 2, indicating an increase of about 8 cwt. an acre.

(7) The technique of the experimental sprayings, by which the detailed figures in the tables were obtained, is described. It is believed that these methods will be of more extended value in the experimental testing of sprays in the field.

In this paper, an attempt has been made to describe the external morphology of eight species of larvae belonging to the family Anobiidae with a view to constructing keys for the identification of these larvae and providing descriptions by which identification can be definitely confirmed. Two keys have been drawn up for use according to whether whole larvae or mounted preparations of parts of larvae are being examined. Notes have been added at the end of the description of each larva giving particulars as to its habitat and points for comparison from the descriptions of other workers.

One point of interest that arises from the foregoing descriptions is that Hedobia, which has usually in the past been classified as a member of the family Ptinidae is definitely an Anobiid when the structure of the larva is considered.

In conclusion, I should like to thank Mr. R. S. Pearson, C.I.E., F.L.S., Director, Forest Products Research, for permission to publish this report.

Observations additional to those made by Dunn (1927) of Culicine mosquitos breeding in “ test ” water containers about a Compound in Southern Nigeria, near Lagos, are here reported for a period of the year (June to December) not covered in Dunn's study. Only the optimum type of container mentioned in Dunn's report (bamboo joints containing water and mango leaves) was employed, and these were placed in the same ten representative environmental situations. The numerical rank of infesting species differed significantly in the two studies only in the case of Culex decens, which dropped from third to last place, and of Aëdes africanus, which rose from tenth to sixth place. The total numbers of infestations in the former study were greater, but this is explainable on the basis of one or several variables, i.e., seasonal differences, elapse of time between studies, or less probably the fact that there were four containers instead of one at each station. The number of infestations at any one station has little relation to the number of resultant adults; there is a wide variation in these numbers.

An analysis of the occurrence of A. aegypti in containers and a discussion of certain bionomical information together with relative weather conditions are included. Brief data are also presented of the incidence of species at three additional stations, one in a centre of dense population (Lagos), one in a suburb (Ebute Metta), and the third isolated in dense “ bush.”

The earliest known cases of the coincident disappearance of tsetse-fly from an area affected with rinderpest occurred in the Transvaal and Rhodesia in the early nineties of last century (Stevenson Hamilton, 1911 and 1912). There is no doubt that the fly either decreased or entirely disappeared from various districts in these two territories following the great rinderpest epizootic in the wild fauna. A satisfactory explanation has not yet been given to account for this remarkable phenomenon.

Fuller (1923) in a most interesting historical review of the tsetse position in the Transvaal and neighbouring territories points out that although there had been a gradual shrinkage of the fly over a period of some years, the disappearance of Glossina from the Eastern low country of the Transvaal can be definitely attributed to the rinderpest epizootic. He further states (p. 347) that “ it has been shown experimentally that disease-laden blood does not militate immediately against the fly.” No reference is given in support of this statement, and I am unable to trace any published experimental evidence in this connection, with the exception of Duke's (1919) work, which is referred to later.

Howard (1910), discussing the tsetse position in the Inhambane and Lourenço Marques districts of Portuguese Territory, states that after rinderpest passed over South Africa the fly began to disappear and that they had been unable to locate a single tsetse-belt in that portion of the country.

1. The conditions of temperature and humidity under which Xenopsylla cheopis is able to complete its metamorphosis are described.

2. The larvae and pre-pupae are easily killed by drying, but the pupae are not. The cocoon does not protect the larva from drying.

3. Development is much quicker at high than at low temperatures.

4. The rate of loss of water from the larva appears to be proportional to the saturation deficiency of the air, at any rate at 18°C., 22°C. and 29°C.—when the time which elapses between spinning the cocoon and the formation of the pupa is taken into account.

The writer is indebted to Dr. P. A. Buxton for reading and criticising the manuscript.

1. More than twenty new forms and variations of tsetse traps are described in this paper for trial, and rejection or improvement, by other investigators. The species of tsetse-flies that they have been tested against have been palpalis, pallidipes, morsitans and swynnertoni.

2. The reactions of the various tsetse-flies to different forms of trap vary in a marked manner. Thus a trap (the Harris) that is excellent for pallidipes has appeared less good, though fair, for palpalis, poor (except at one season) for morsitans, and useless for swynnertoni. Another (the SS and the SSB) is particularly excellent for palpalis, excellent for pallidipes, mediocre for swynnertoni, and perfectly useless for morsilans.

3. Tsetses, pallidipes in particular of the two species tested, have been found to react also most strongly to the scent of an invisible animal placed in a trap. It is not known yet whether this attracts at a distance or is merely a close-range attraction, inciting the flies that have arrived in any case to such effort as takes them in larger numbers into the traps, but the latter does undoubtedly happen.

4. If the attraction be long-range, the flies do not readily distinguish between the source of the odour and conspicuous objects within its range. They go to and into a trap, even a trap that usually does not catch them, in greatly enhanced numbers when cattle are in its neighbourhood.

When studying the fauna of the soil it is obviously of the utmost importance to use such methods of collecting the animals as are thoroughly reliable and efficient, so that one can be reasonably sure of getting practically all the animals existing in a given material. It is not to be expected that one method will ensure successful collection of all the animals, because some react in one way towards the agents chiefly used, viz., strong light and heat, others react in another way. For instance, some animals, such as Tardigrades and Rhizopoda, encyst themselves when subjected to dryness and cannot be forced to move downwards away from the light and dryness as most arthropods do. As pointed out by the author (1928) all methods of mechanically separating the animals from the substratum by sieves, etc., are worthless unless applied to larger animals such as Oligochaeta, larger beetles and snails. For all smaller animals the only safe method is the automatic one based on their reactions towards light and dryness, which was devised by the late Professor A. Berlese in Florence in 1905.

This apparatus is so well known that it is not necessary to give a detailed description of it, nor need I dwell on the more or less similar apparatus constructed later, except Tullgren's, because the latter, constructed in 1917, has been used by several investigators. Tullgren substituted the funnel filled with water and heated by gas, which Berlese used for the purpose of drying the material containing the micro-arthropods to be collected, by an electric bulb suspended above the material in a cylindrical funnel at a distance of about 5 cm. above the material.

A description is given of the detection of an active breeding place of A. mauritianus in the Kurdani River, near Acre. This species was first reported by Barraud in 1920 as breeding in the swamps of the Kishon and Auja. Since that time neither Buxton nor the other workers in Palestine have been able to find this species. It is conceivable that the reason for the failure is due to the fact that the larvae closely resemble those of A. hyrcanus and that like it, the adult is a swamp feeder and not a house visitor.

Almost all of the studies here reported were made in one small region, so that very little new information was secured on the ranges of the species of mosquitos under consideration.

Our investigations regarding breeding-places were limited to a few species. Aëdes vittatus was found occasionally breeding in tree-holes in Ibadan. Aëdes irritans adults were taken at Ibadan, which is so far inland that this species must sometimes breed in places other than crab-holes at the edges of salt or brackish water. We did not, however, find the larvae of this species at Ibadan. The favourite breeding-place of Eretmopodites chrysogaster was found to be small collections of water in fallen leaves (especially those of cocoa trees) lying in moist and densely shaded places. Because of the abundance of Mansonia africana in places practically free from Pistia, we conclude that in the vicinity of Lagos it must breed abundantly on other plants. The long flight range of this species was taken into consideration in arriving at this conclusion. An extensive search failed, however, to reveal these plants. M. uniformis, also abundant in the vicinity of Lagos, does not breed there upon Pistia, but an extensive search failed to reveal its breeding-place.

The plant Clidemia hirta belongs to the natural order Melostomaceae. It is of shrubby growth, with a hard tough stem and produces quantities of dark purple berries, filled with minute seeds. These berries are much relished by certain birds, which feed upon them and distribute the seeds. The leaves are covered with fine hairs and the plant is not eaten by stock.

The plant is a native of the West Indies, Central America and the Northern portion of South America. It is supposed to have been introduced into Fiji from British Guiana at some time prior to 1890. That this was the origin of the plant is supported by slight differences observed by the writer in the foliage of the Trinidad, Panama and British Guiana forms of the plant, the Fijian one closely resembling those of the last named country.

In Fiji the plant was first observed along the fences of paddocks in the Waimanu Valley, whence it spread with great rapidity, quickly becoming a weed of major importance. By 1919, when the writer arrived in the country, thousands of acres were covered with it to the exclusion of almost all other growth. On good soil it formed a stand five or six feet high, through which the cattle were only able to keep open narrow paths. Not only did it rapidly occupy the open grass lands, particularly the rich dairying and fattening country, but it thrived almost equally well under the shade of coconut and rubber plantations, leading to loss of many fallen nuts and entailing greatly increased weeding costs.

This is a third of a series of papers dealing with zoophagous gall midges of the world. The first, “ Gall Midges as Enemies of Aphids,” was published in 1929 (Bull. Ent. Res., xx, 1929, pp. 433–442) and the second, “ Gall Midges as Enemies of the Tingidae, Psyllidae, Aleyrodidae, and Coccidae,” appeared more recently (op. cit., xxi, 1930, pp. 319–329).

In this paper the species of gall midges whose larvae have been reported as preying on mites are dealt with, the first reference mentioned being in each case that of the original description or record. Practically all the literature available consists of specific descriptions and little is stated about the bionomics of the species with a few exceptions. It is a matter for regret that such scant attention has been paid to this aspect of biological control, especially in view of certain statements claiming that the larvae of various gall midges are of considerable importance in the natural control of red spider. It is with a view to stimulating further research in this direction that the present paper has been compiled.

It has been thought advisable to divide the paper somewhat arbitrarily into separate sections, dealing firstly with those species of gall midges preying on free-living mites and secondly with those species preying on gall-inhabiting mites. A further section deals with those Cecidomyids which may feed on mites. As an additional convenience, a list of plants on which the mites live is appended. The Cecidomyids which may be predacious on mites (see section 5) are not, however, included in this list.

It appears from the literature that the species of Longitarsus recorded from ragwort (Senecio jacobaea) or its ally the groundsel (S. vulgaris), are L. dorsalis, F., L. suturellus, Duft., L. senecionis, Bris., L. jacobaeae, Wat., L. ochroleucus, Marsh., and L. gracilis, Kutsch.; the last named species is also recorded by Bedel from Tussilago. In addition L. succineus, Foudr., has been associated with various composites, such as Eupatorium cannabinum and Chrysanthemum spp. but, apparently, never before with Senecio.

Much of the first part of this paper is in the nature of a continuation of the work previously published by the author. (Bull. Ent. Res., xxi, 1930, pp. 201–256). For this reason only a brief description can be given of the locality, vegetation, game, and fly-round methods ; those desiring a fuller knowledge on these subjects are referred to the above-mentioned paper. Again, a certain amount of repetition has been unavoidable. Some results obtained from only one year's observation have now been confirmed during a period of four and a-half years, and so have been given again. It is felt that this repetition is justifiable as the results in question are of special value, in that they are derived from four and a-half years continuous observation upon the same fly-belt, the method employed being constant throughout the whole period.

The writer is in charge of Kikori Entomological Station, which he opened in March 1928 ; nine months later he was joined by his assistant Captain V. A. C. Findlay.

The native village of Kikori is situated at the foot of the Masai escarpment, which bounds the Masai Steppe on the west. Kikori lies about 45 miles north of Kondoa-Irangi (the principal centre of the district), its approximate bearings being Latitude 4° 21′ S. and Longitude 33° 19′E. ; its elevation is 4,158 feet above sea-level.

(1) Aèdes vigilax migrates for long distances and together with Mucidus alternans disperses over considerable areas under favourable physiological conditions.

(2) Migrations are only undertaken when suitable winds make dispersal possible ; north-westerly winds distribute, under suitable atmospheric conditions, untold numbers of A. vigilax all along our foreshores.

(3) In summer the appearance in large numbers of both A. vigilax and Mucidus alternans heralds the approach of a storm.

(4) The presence of mosquitos found in wide areas in Queensland apparently devoid of water may be explained : (a) By the existence of breeding facilities in tree-cavities and similar breeding-places not visible to a casual observer ; (b) by the prevalence of suitable carrying winds by which mosquitos are blown for short or long distances from their native breeding-places ; (c) by extreme localisation of mosquitos breeding in small quantities of water mostly inaccessible to the casual observer.

During the course of an investigation having as its object the control of Thrips imaginis, Bagnall, a pest of deciduous fruit blossom in Australia, it has been found necessary to make numerous counts of the number of these insects found infesting various flowers. These counts are made for two purposes, the principal one being the determination of the effect of attempted control measures. In addition, counts are taken every day throughout the year for the purpose of following the seasonal fluctuations of the numbers present in the field.

At the beginning of the investigation, flowers were picked, placed in closed cardboard cylinders and taken into the laboratory. Each blossom was then examined separately for thrips, the insects being captured by means of a moistened camel-hair brush, with which they were transferred to a small dish of 70 per cent. alcohol. This method was slow and not particularly dependable, as on hot days when the thrips were active, as soon as a flower was placed on the laboratory bench, numbers of insects would leave it and make off in all directions, even taking to flight.

As a result of the unsatisfactory nature of the procedure described above, an apparatus has now been devised which is saving both in time and patience, and gives reliable results (fig. 1). It consists of a glass cylinder 5 inches in diameter and 10 inches high. The top is closed with a close-fitting lid.

(1) The life-history of S. destructor was investigated, and it is shown that it is primarily a saprophagous feeder but with distinct potentialities for occasional parasitism.

(2) Two species of parasites were bred out of Locusta and Schistocerca from the Red Sea Coast: Blaesoxipha lineata, Fall., and B. filipjevi, Rohd.

(3) The percentage of parasitism was high; 39 per cent. of the adults examined in the area in December 1932 either contained parasites, or had been parasitised and recovered.

(4) The recovery from parasitism was high; 19 per cent. of the locusts examined had been parasitised and recovered.

(5) The life-history of B. lineata and B. filipjevi was investigated in the laboratory; Olsuf'ev's observation that B. lineata is not a very effective parasite was confirmed. A 78 per cent. recovery from parasitism by B. lineata was obtained. Only 38 per cent. of the locusts parasitised reproduced.