Mr. H. Hargreaves, Government Entomologist, Uganda, has sent me identified, larvae of several species of beetles. I now describe those which are of economic importance.

A detailed study of the bionomics of Glossina longipalpis, Wied., was undertaken at Takoradi, the principal port of the Gold Coast in West Africa, and lasted from February to September 1931.

The topography of this country is undulating; the vegetation is of Transition Forest type, intermediate in character between Rain Forest and Savannah Forest, and of an exceedingly dense, homogeneous nature, with a few small glades in the forest, and interrupted by large open marshes on the lower and flatter ground.

The climate is remarkably equable, with a low mean annual rainfall between 40 and 45 inches, but constantly high humidities, owing to the moisture-laden sea-winds. There is a double rainy season, the main rains from April to July, and a second shorter period of rainfall in October and November.

There is a rich mammalian fauna, with the exception of the larger game animals.

Three species of Glossina occur: G. longipalpis, Wied., the commonest, evenly distributed throughout the bush, and the only species dealt with in this paper; G. palpalis, R.-D., confined to water-courses and the edges of lagoons; and G. medicorum, Aust., rarely met with.

Two isolated fly-belts, identical in every way, were studied. In one, section A, flies were caught and killed daily; in the other, section B, the control area, the flies were liberated after noting the catches. By September, the tsetse population of A had been reduced to less than one-third of that of B, presumably the effects of catching and killing.

The main food hosts of this species were the bushbuck and duiker, ubiquitous in this forest. When these small game animals were driven out of a third fly-belt, section C, by farming and wood-cutting, the fly quickly and completely disappeared. This species was never found to feed on reptiles, although they were common in the fly-belts.

Meteorological observations in the open country and in the fly-belts showed a consistently lower temperature and higher humidity in the latter, as well as its greater equity in these factors. The movement of the fly into the open was apparently governed by humidity, the greatest movement taking place when the humidity of the open was within the normal range of fly-belt humidity.

By statistical methods, coefficients of correlation were determined for the fly's density-activity and various climatic factors of the fly-belt. The fly showed a high positive correlation with temperature, and a lower correlation with humidity, of which saturation deficit was a better index than atmometer evaporation. There was a significant correlation with sunshine, but none with rainfall. This correlation with humidity was mainly a temperature effect, as was also the correlation with sunshine. Temperature was evidently of major importance. There was a significant negative correlation between fly and relative humidity, measured with a wet and dry bulb hygrometer in a screen in the open.

All correlations were greatest when considered direct, the fly catches with simultaneous climatic readings, indicating that these factors influence the activity of the fly in this way, rather than its density. The fly was found to be inactive at temperatures below 74°F., with high humidities of 80 or 90 per cent. or over. This explains the major influence of temperature, shown by the methods of correlations. The temperature range in the fly-belt, during the period of observations, was close to the temperature significant for the fly's activity, and therefore variations produced marked reactions; the humidity range was much closer to the fly's optimum and therefore better tolerated.

There is marked daily rhythm in the fly's activity, which is only influenced by climate under extremely unfavourable conditions of temperature or humidity.

The distribution of G. longipalpis in the Gold Coast is dependent upon the humidity of the ecoclimate, rather than upon temperature. It occurs in three main vegetational types—Transition Forest, Inland Savannah Forest, and Coastal Savannah— where the range of humidities is between 50 and 80 per cent. R.H., and temperature between 75° and 85°F. It does not occur in the Rain Forest, where the relative humidity is constantly above 80 per cent., or in northern Savannah, where the humidity is as low as 30 per cent, in the dry season.

The main breeding season was from March to July with its maximum in May, at the height of the rains.

This species was found infected with Trypanosoma gambiense, T. congolense, and T. vivax at Takoradi, and is probably second in importance to G. palpalis as a vector of sleeping sickness in the Gold Coast, but at present of less importance than G. palpalis or G. tachinoides in the transmission of trypanosomiasis of stock.

The receding of the Ashanti forest and the present development of the Colony may cause even greater contact between this species of tsetse and man. The main policy for control should lie in improving and controlling the natives' methods of cultivating the bush. Farms should be as close to the village as possible, contiguous, and kept under cultivation, if possible, permanently. Clearings should be made of at least 100 yards width round bush villages, and of at least 200 yards width round important towns. Small clearings and isolated farms are considered a danger.

Our knowledge of the distribution of tsetse-flies affecting domestic stock in Kenya Colony is of a very general character. A good deal of the information requires confirmation; and much needs to be done to ascertain the extent and the nature of the permanent fly-infested areas, and the seasonal dispersion of the tsetses from their permanent haunts.

1. In 1927 a suggestion was made by P. A. Buxton to introduce Megarhinus to Samoa and Fiji for the control of Aëdes scutellaris (variegatus), which transmits human filariasis.

2. In 1929, C. E. Pemberton introduced M. inornatus from New Britain into Hawaii, where it has apparently failed to become established.

3. In the same year the writer was sent to Java to obtain parasites for a coconut pest in Fiji; and in 1930 received instructions from the Fiji Government to collect and transport Megarhinus from Java to Fiji.

4. During the latter half of 1930 early stages of Megarhinus splendens—the commonest and most widespread species in Java—were collected from tree-holes, bamboo stumps and tubs at Buitenzorg.

5. Experiments were conducted at Buitenzorg to ascertain how long the larvae could be kept in a healthy condition by restricting their food supply. It was found that they matured normally on a reduced diet after a development lasting as long as two months. The most rapid development from egg to adult was found to take 24 days. Attempts to breed the adults in captivity were unsuccessful.

6. In January 1931, a colony of M. splendens consisting of 283 larvae was taken to Fiji; 45 died or emerged as adults during the voyage of 28 days.

7. On 27th February 1931, 238 M. splendens were landed at Suva.

8. Colonies for distribution to various parts of Fiji were bred in Suva during 1931 and 1932, and by April of the latter year 51 colonies, composed of nearly 3,000 individuals, had been liberated.

9. Megarhinus was bred at Suva by liberating the pupae in barrels kept out of doors. The adults which emerged laid most of their eggs in the barrels in the absence of other breeding-places in the vicinity. The larvae were collected from the barrels when they reached their third instar. They were fed in captivity until they pupated, and then liberated as pupae in colonies sent to various parts of the group.

10. By the end of 1931 Megarhinus had been recovered at six of the colony sites in natural breeding-places, and is now well established. The most favourable type of country in Fiji for Megarhinus to colonise is the swamp land with trees of Inocarpus edulis (“ivi”), which occurs near the coast on many islands.

11. An account is given of the spread of Megarhinus through an Inocarpus swamp on the island of Taveuni, where a survey was made of the Megarhinus and Aëdes content of all the tree-holes within six feet of the ground. M. splendens was present in rather more than 50 per cent, of the holes and Aëdes variegatus in about 40 per cent. The probability is that in this locality Megarhinus has caused a 20 per cent, reduction in the number of tree-holes containing Aëdes during the three months succeeding its liberation.

12. It was found that in most places, in the forest especially, Megarhinus spreads very slowly–undergrowth making an effective barrier to its flight.

13. A. variegatus breeds mostly in tree-holes, tins, holes in rocks, coconut husks, wooden gongs in native villages and crab-holes (the last not yet proved in Fiji). Of these places Megarhinus has so far bred only in tree-holes and tins (very occasionally). It will probably breed in native gongs but unlikely that it will breed in either crab-holes, rock-pools or coconut husks. Therefore at the best it can hardly be expected to reduce the numbers of A. variegatus in Fiji by more than 5 per cent. But even that would justify the trifling expenditure which has been devoted to the project.

14. Studies of the habits and life-cycle of M. splendens made in Java and Fiji revealed the following points of interest:—Incubation period always about 2 days; larval stages, minimum 16 days (food abundant), maximum 134 days (food scarce); pupal stage always about 6 days. The minimum period for a generation is about 30 days.

In spite of the lower average temperature in Fiji very little difference was noted between the rate of development in that country and in Java.

The adults are diurnal in habit. They mate when settled; not on the wing, as do most mosquitos. The eggs are dropped singly on water where they float on the surface film. They are almost round and glossy white. Oviposition continues over several weeks, and is most prolific in sunny weather. The egg capacity was not determined.

Larvae of Megarhinus fed on tadpoles, Tipulid larvae, Chironomus larvae, and all sorts of mosquito larvae. They do not object to feeding on those mosquito larvae whose bodies are very hairy. They are cannibalistic.

15. In May 1933 a small colony of M. inornatus was brought by the writer from Rabaul to Fiji, since it was reported that this species had been found in New Britain breeding in coconut husks. This species is now being bred in Suva, whence, if it survives, it will be distributed to other parts of the group. Its immature stages are of similar duration to those of M. splendens, so that it would seem very unlikely that this species will succeed in reaching maturity in coconut husks in Fiji, complete evaporation of the water taking place too quickly.

M. inornatus is structurally very close to M. splendens, and it is quite possible that the two species will eventually hybridise in Fiji.

1. The first record of important damage due to borers in Mauritius dates from 1856, the species being the spotted borer, Diatraea venosata, Wlk. From 1856 to 1897, two other species of borers were introduced, the pink borer, Sesamia vuteria, Stoll, and the white borer, Grapholita schistaceana, Snell. From 1897 to 1916, the damage caused by these three borers decreased gradually, so that from 1916 to 1928 these pests were considered by planters as being of minor importance. From 1928 to 1932 an increase in the damage due to the spotted borer was observed nearly all over the island.

2. The spotted borer causes important damage on the coast belt during the dry and cold months, i.e., April to July. The pink borer, distributed all over the island, causes damage of medium importance to young canes; it occurs with intensity during the wet and hot months of the year, i.e., December to April. The white borer is also distributed nearly all over the island but causes damage of relatively slight importance in plantations, with the exception of very rare occasions when it occurs sporadically as a serious pest.

3. The losses due to the pink and white borers vary with the localities and are difficult to estimate. As an average, Rs.6·00 per arpent is incurred for control leasures against these pests.

The spotted borer which attacks mature canes causes losses both in the field and in the factory. The reduction in the field, per arpent, averages 15 per cent. The loss in sugar averages 2.3 per cent., i.e., 16 per cent, of sugar in cane. The gross loss per annum for the whole island is about 1½ million rupees, and the net loss approximately Rs.125,000.

4. The proportion of canes attacked by the spotted borer averages 30 per cent. From estimates made according to the method of Wolcott, in Porto Rico, it was found that the percentage of borers per 100 lb. of cane is 39, as a mean, and the number of borers per acre averages 15,698. The mean percentage of stems attacked by 1 to 5, 6 to 10, and 11 to 15 borers is of 87·6, 10·1 and 2·2 respectively. The proportion of nodes attacked varies between 10 and 25 per cent. approximately.

5. The cane varieties that are heavily attacked by the spotted borer are M.55, M.131, D.109, M.1474, White Tanna, B.H.10/12, R.P.6, D.K.74, D.130 and R.P.8.

6. The various methods of control used in the island for the last 15 to 20 years are discussed. Against the pink and white borers the use of trap plants is recommended as well as the collection of larvae. The burning of trash in the fields is to be avoided.

In the case of the spotted borer the destruction of larvae in the tops to be planted is recommended. A practical method consists in the immersion of the tops in cold water during 72 hours, or in hot water at 50–51°C. for 2 to 2½ hours, or 52°C. for 30 minutes, or in saturated lime-water for eight hours.

7. The breeding of the larval parasites is recommended on estates where larva collecting is practised.

8. The advantages or disadvantages of larva collecting and burning of trash are still under consideration.

This subject has been discussed very fully by Dr. T. A. M. Nash and the writer in two recent papers (Bull. Ent. Res. 24, 1933, pp. 135, 475–477). There is, however, one point which it is felt should be made clear. Dr. Nash states that the writer, “working in the Western Kondoa fly-belt, finds the more normal type of obvious concentration. In the dry season tsetse become more numerous in Berlinia-Brachystegia woodland immediately surrounding ‘vleis.’ Owing to the small size of these ‘vleis,’ which are only about 75 yards across, the fly appears to an observer to be concentrated in them; in reality they are probably living in the shade of the surrounding weeds and fly out to attack the investigator. Passing through Berlinia woods in this country one finds fly more numerous on the edge of “vleis,” probably because the trees are almost non-deciduous owing to sub-soil water.”

Among the diverse forms of insect life infesting stored agricultural products in South India those belonging to the Lepidoptera are by no means unimportant. Though no accurate estimates of the annual losses in value of grain, pulses, etc., due to their depredations are available in this country, it has to be admitted that the extent of the damage may occasionally be considerable. It is, therefore, unfortunate that these insects have not attracted sufficient attention at the hands of Economic Entomologists in this country; consequently very little information is available as to the exact identity of the species, their relative importance, or their life-histories. The present investigation was undertaken to make a detailed study of this problem in South India with a view to elucidating the points just raised.

In a previous paper (Pospelov, 1926a) I pointed out that adult locusts (Locusta migratoria migratoria, L.) kept in a cage at a constant temperature of 35–38°C. (95–100°F.) and at sufficient humidity attained sexual maturity in a month, while those kept at 20–30°C. (68–86°F.) failed to mature even after three months.

A study has been made of the biology of Depressaria conterminella, Zell., the most important willow-shoot moth occurring in commercial willow beds of Lancashire and Cheshire.

The eggs are laid in June-July in bark crevices on the stocks near the level of the soil. Hatching takes place in the following spring, beginning about the time the buds open. The eggs are described.

On hatching the larvae travel to the opening buds. First instar larvae tunnel through the outer leaves into the buds, but larvae in the later stages crawl between the leaves, spinning them together to form a feeding shelter. Larvae have four instars and at the third ecdysis there is a marked colour change. Both larval forms are described. In the course of feeding each larva destroys 3–4 shoots. Infested shoots are illustrated. Pupation takes place in the soil and adults emerge after about three weeks.

The habits of the moths are described. The species is univoltine and no instance of parasitism has so far been observed. A list of other Lepidoptera bred from the shoots of willows is given.

The nature of the crop does not permit of costly control measures. The study of the biology suggested that infestation might be checked by delaying harvesting until after the larvae hatched. In an experiment in the field it was found possible to reduce infestation from over 40 per cent. to under 5 per cent. by this method. Infestation was also reduced by burning waste hay over the rows of willow stocks during the dormant season.

Hibernation of P. papatasii in Palestine is primarily caused by low temperature, but cyclical (? hereditary) factors exist which modify the phenomena of hibernation to a certain extent, as indicated by the following facts.

1. Occurrence of a gradually increasing number of resting larvae during autumn, with a maximum of hibernating larvae in the first winter generations.

2. A gradually increasing prolongation of development during the late summer generation, with a maximum duration of development in the first winter generations in larvae kept at 30°C.

3. The pupation of hibernating larvae kept at 30°C. in spring at the same time as of larvae kept in out-of-door conditions during the winter.

There is always a certain number of resting larvae (2 to 12 per cent.) throughout the summer in otherwise active broods. This inhibition of development shows that a latent inclination to diapause exists in all generations, and that diapause may also be brought about by unfavourable conditions.

No relation could be found between the interval between hatching and oviposition and asthenobiosis.

A few years ago a paper appeared in this Bulletin (Buxton, 1931) describing methods of controlling and measuring humidity. Since that paper was written, we have evolved a number of improvements which tend to make the methods easier in practice, though none of them are novel in principle. It is now known that humidity has diverse and unpredictable effects on many insects. In experimental work it is advisable that humidity should always be measured and controlled even if it is not a factor in the experiment. Moreover, workers should state what method of measurement or control they have adopted.

1. The number of egg-tubes and the number of eggs in each tube varies in accordance with the food and the climatic and microclimatic conditions of each habitat. The majority of Siberian grasshoppers have adaptations in the ovaries which enable them to take full advantage of the available heat.

2. In the species possessing 10 or more egg-tubes, their number varies in different parts of the distribution area. It decreases towards the centre of the area with increasing warmth and dryness, and increases towards the colder and more humid margins of that area (e.g., in the Far East and in Western Europe).

3. The potential fertility is more or less stable in different species of grasshoppers, and in the species studied it fluctuates between 84 and 388 eggs per female.

4. There is no correlation between the potential fertility and the abundance of the species in nature, for the greatest fertility is met with in those species which occur but rarely. The injurious (i.e., very numerous) grasshoppers have a medium, or somewhat less than a medium, potential fertility.

5. The actual fertility is greatly dependent on the environment and has a wide range of fluctuation.

6. Lack of food in reservations was observed to lower the fertility of grasshoppers by 30–40 per cent. The parasites (Blaesoxipha spp., Mermis spp.) greatly reduce the degree of fertility of the Siberian grasshoppers. However, the percentage of infestation by these parasites is low, but in the reservations it is somewhat higher than outside. Thus, the actual fertility in reservations is rather lower than outside.

7. The outbreaks of the Siberian grasshoppers are determined by the climatic and microclimatic conditions. The fluctuations in fertility never have any real importance in causing the outbreaks. Lack of food, parasites, predators and diseases are of minor importance; among the latter the main factors are the diseases of the egg-pods, which again depend on the microclimate.

Methods have been devised and applied to an intensive study of the course of illworm activity on numerous rain-grown and irrigated crops. These were developed the first instance to enable accumulation of data considered essential for evaluating eusefulness of certain egg and larval parasites when released experimentally. and they have now been extended to the point of providing continuous, quantitative data on bollworm-food-plant relations. This work has been placed on a routine basis. The information that is supplied comprises:—

1. The course of oviposition in point of duration, magnitude and time of occurrence in the life of a host crop. This serves well to indicate the true course of moth activity on different food-plants, the relative attractiveness of these and to reveal if such matters are maintained under different conditions and bear definable relations to growth stages of a food-plant.

2. The identity and activity of egg and larval parasites under natural conditions.

3. The identity and activity of insects predatory on the eggs and larvae, as occurring in the varied insect communities associated with different crops.

4. Comparative mortality of larvae in the different crops where oviposition has been recorded.

Continuous records of egg-laying by the American bollworm, H. obsoleta, F., have been taken at the Cotton Station, Barberton and on several farms in the neighbourhood. Cotton and maize were the principal crops, but the surveys included a number of other food-plants. Egg-laying was found to be very closely associated with the period of bud and flower production, and its duration on different hosts thus varies according to the flowering habit.

In the case of maize, egg-laying hi quantity commences when the tassels (stam-inate flowers) are extruding, and the peak of the oviposition is passed before silks (pistillate flowers) are abundant. This is at variance with the generally accepted view that the plant is most heavily oviposited upon during the silking period. The typical course of oviposition on maize here lasts for two to three weeks only.

Numerous instances were observed where oviposition by Heliothis occurred on maize in tassel to the practical exclusion of neighbouring cotton in freely fruiting and healthy condition, and the possibilities of exploiting this relationship are discussed.

As regards winter-irrigated vegetable crops and citrus orchards, data are given showing that the American Bollworm breeds extensively in these crops, particularly so a month or two prior to the appearance of rain-grown cotton, maize and tobacco.

The irrigated crops in the Barberton and contiguous districts are regarded as a main source from whence bollworm on cotton is derived. Citrus orchards of which there are relatively large acreages may be of particular importance in this regard.

The methods of obtaining information on the course of moth emergence are described. Data are given that explain the course of moth activity in winter crops and indicate when moths enter rain crops from winter breeding areas.

The only larval parasite of importance under natural conditions is Sturmia inconspicua, but this fly does not parasitise young larvae. There is a scarcity of insects parasitic on American bollworm larvae, and the question of importing them should be considered. Breeding and experimental releases of a larval parasite, Microbracon brevicornis, are discussed.

Two important egg parasites are a species of Phanurus and Trichogramma lutea.

An Anthocorid bug, Orius sp., destroys large numbers of bollworm eggs and probably also young larvae, and this insect and certain species of ants are the most important agents in natural control.

As regards the red bollworm, Diparopsis castanea, Hmps., it is concluded that the use of trap crops should be discouraged for general adoption as a means of controlling it owing to the danger, through inattention to the trap crops, of breeding this boll-worm in them. Its incidence in former years is briefly reviewed. Of late years the annual infestation has diminished greatly in some districts but not in others. The variations in this regard are attributed mainly to the presence or otherwise of ratooned cotton, particularly in mild winters and to seasons of very late planting.

Many years ago Bezzi realised that the species placed in the genus Ceraiitis, MacL., needed division into smaller groups. Among those he first delimited, Carpoph-thoromyia, Aust., may well be retained as a genus, but most of the others, Parda-laspis, Bez., Perilampsis, Bez., Trirhithrum, Bez., etc., have hardly more than sub-generic value. It is therefore proposed to study all the species concerned in order to discover the true limitations of the groups; and also with a view to stabilising the species themselves for a further study involving dissection of specimens. The last point is of some importance because more detailed work on the morphology cannot be carried out at all satisfactorily until one is quite sure of the specific identity of the specimens used. Further, as the dissection of insect types may be undesirable and few institutions, if any, would allow it to be done, it becomes essential to have specimens critically compared with types, and until this is done, there must always remain some element of doubt in identifications. This paper is thus a beginning of a series on a nreliminarv studv of the subsrenera of Ceratitis.

The black-headed palm caterpillar (Nephantis serinopa, Meyr.) has been known to be a serious pest of coconut palms both in Ceylon and South India for many years past, and during the past ten years its appearance on a serious scale along the Malabar coast in South India has been attracting the attention of the Entomological Section of the Madras Agricultural Department. Among the different methods of control, the utilisation of the natural enemies of the pest has been tried to some extent. One of the more important natural enemies found to exert some appreciable influence on this pest was a Eulophid wasp, Trichospilus pupivora, Ferr. As one of the officers of the Entomological Section engaged in the work connected with this coconut pest, the author had opportunities of closely studying this parasite, and in this paper a brief account is attempted of the bionomics of this insect and of some methods employed in breeding it on a large scale.

In January 1932 the writer received for examination a sample of narcissus bulbs, variety Diadem. The bulbs, which had been grown in Abingdon, England, for a number of years, were submitted on account of their persistently unsatisfactory growth. It was found that they were heavily infested by a species of Tarsonemid mite, which was present in sufficient numbers to account adequately for the unhealthy condition of the bulbs. No record could be found relating to the occurrence of such an infestation actually in Europe; the condition was, however, already known in the U.S.A. Ewing4 in 1929 described a new Tarsonemid occurring in narcissus, which he named Tarsonemus approximatus, Banks, var. narcissi, Ewing. The mite was named from material obtained in narcissus bulbs from the Pacific coast, which bulbs it appears had been imported from Holland. Doucette2 in the same year, 1929, published a short account of the activities of the mite with which he had become familiar in both Philadelphia and California as early as 1925, in these cases also in bulbs of Dutch origin. No other reference to the mite could be found in literature, although it is perhaps hardly necessary to state that allied species are known to be highly injurious to plants, e.g., Tarsonemus tepidariorum on ferns (Cameron1), T. fragariae and T. pallidus on strawberry (Massee7), and T. essigi on blackberry, etc. (Essig3).

Records of stainer infestation in cotton have been taken at the Cotton Experiment Station, Barberton, South Africa, since 1931, and in 1933 a uniform system of recording stainer populations in cotton by sampling 10-acre blocks was extended to four farms in the Barberton district, three farms in Swaziland and the Cotton Experiment Station at Magut, Natal.

The records so obtained show that stainers normally appear in plant cotton in late February or early March. D. intermedium, Dist., is present in comparatively small numbers throughout the season; D. nigrofasciatus, Stål, and D.fasciatus, Sign., are very variable in relative abundance. In 1933 the latter species was practically absent from cotton at all points save those in the vicinity of ratoon or standover cotton, but in 1931 and 1932 it appeared in numbers equal to those of D. nigrofasciatus and bred up a very much larger population in the crop.

Where normal migration occurs, all three species of stainers pass through two and a partial third generation in the crop; at the end of the season part of the adults migrate from the crop and the remainder, together with the bulk of the nymphs, may be destroyed by appropriate clean-up measures.

Extensive surveys of the Transvaal Low Veld and rapid tours of portions of Swaziland, Zululand and Portuguese East Africa, indicate that the principal wild food-plants of stainers in these regions comprise the genera Abutilon, Gossypium, Hibiscus and Sida in the Malvaceae, Melhania and Sterculia in the Sterculiaceae and Adansonia in the Bombaceae.

The Malvaceous host plants and Melhania are all herbaceous or shrubby species and upon these D. nigrofasciatus is frequently found. It is possible that colonies of these plants existing in sheltered situations may provide overwintering grounds for this species.

Two species of Sterculia are known, S. rogersii and S. murex. The former is wide-spread and abundant throughout the Low Veld and probably constitutes the main breeding-ground of all species in the early summer. The latter species is rarer, and its status as a food-plant is not yet fully investigated.

The Baobab occurs in large numbers in the Northern Transvaal, but it has not yet been proved to be a winter food-plant. The latest information shows that during the summer it may commonly be infested with D. fasciatus.

In conjunction with stainer population records in the crop, weekly systematic records of damage to the crop have been obtained from samples of bolls which have been examined for puncturing and graded for degree of staining. The number of punctures per boll and the percentage staining are strongly correlated, but it has proved difficult to correlate these with stainer population, except where young bolls are examined.

Internal boll disease, particularly early in the season, may be due to bacterial organisms transmitted by species of Hemiptera other than stainers. Later in the season the infection of the crop is more definitely due to Nematospora spp., of which N. gossypii is commoner than N. coryli.

All species of stainers collected on cotton have been found to transmit Nematospora, though they are not efficient vectors until the fourth instar is reached. Adult stainers collected on wild food-plants (Gossypium herbaceum var. africanum, Hibiscus spp., and Sterculia rogersii) have been shown to be infected with N. gossypii.

The etiology of the disease produced by both species of Nematospora has been followed in inoculation experiments, using pure cultures. The rate of spread of the disease varies with the age of the boll at the time of inoculation, being slower when the boll has passed middle age. In neither species does staining extend beyond the foculus in which infection starts, nor does the fungus occur within the seed except lollowing direct puncturing of the seed.

The fact that the staining is not co-extensive with the region occupied by the fungus, but goes far beyond it, and that a pathological condition indistinguishable from that due to the living organism may be produced by injecting a sterilised suspension of the fungus, suggests that the death of the lint hairs, producing staining, is due to a toxic substance liberated by the developing fungus.

This is an account of work carried out in Kordofan on behalf of the Imperial Institute of Entomology. The period August-September 1931 was occupied with preliminary surveys and observations on hopper bands. From July to September 1932 and from March to July 1933 the ecology of the solitary phase of Schistocerca gregaria was studied at Um Darag ; and in January 1933 a locust survey of the more northern parts was carried out.

In the British Solomon Islands Protectorate Agricultural Gazette (1 no. 3, pp. 2–3, pl. i, July 1933) Mr. R. J. A. W. Lever has described and illustrated the life-history of a Coreid which is injurious to the inflorescence of the coconut palm. This species which had previously been provisionally referred to the genus Dasynus now proves on further investigation to be referable to the closely allied genus Amblypelta, and is herewith described.

During the last decade, entomologists have made progress in understanding the environment in which certain insects live; in particular, we begin to understand the effect of certain physical and chemical factors, which make up a part of the environment. With this gain in knowledge, it is sometimes possible to forecast outbreaks of insects and of diseases conveyed by them, and one can sometimes say that a particular alteration of the environment will result in loss or gain. But so far as mosquitos are concerned, one must admit that though much work has been devoted to the analytical study of the water in which the early stages are passed, the results are disappointing. A consideration of the published work suggests several reasons for this. Investigation into the ecology of the mosquito has had a vogue, and much of it has been done by workers who were isolated and whose knowledge of chemical technique and freshwater biology was limited. Apart from that, the inherent difficulties are great, for the worker must hunt for the limiting chemical and physical factors among a host of others which are doubtless unimportant, and there are few clues to indicate which of the chemical constituents of the water affects the mosquito. The data are therefore voluminous and it is difficult to reduce them to order and present them so that they can be readily understood.