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.

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.

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.

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.

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.

In our investigations on Smynthurus viridis, L., a study has been made of the population of this species, in an area of lucerne, at intervals of three and four days throughout the season.

The density of the population of the species in a favourable pasture is markedly affected by the relative abundance of certain food-plants, especially leguminous species and particularly clovers such as subterranean clover (Trifolium subterraneum) and lucerne (Medicago sativa).

The activity of the insect is intimately associated with the moisture of its environment, and the moisture content of the surface soil is one of the most important factors affecting the environmental conditions.

Considering the habits of the insect, it was felt that the sweeping method would not give a reliable record of the total population in a given area of pasture. A sample obtained by sweeping with a net does not include individuals on or near to the surface of the soil. The relative proportion of individuals situated on or near the soil surface and those situated further up the plants varies considerably from time to time, according to the meteorological conditions, the growth of the herbage and the moisture content of the surface soil. It was necessary therefore to devise a simple method by means of which a more accurate record of the total population in a given area could be obtained.

L. sericata, L. cuprina, Ch. rufifacies, C. stygia and C. augur have been bred through many generations in captivity. These flies were bred in artificial light as well as in sunlight. Inbreeding had no effect upon activity, fecundity or length of life.

A diet of protein is necessary for the maturation of ova but not of spermatozoa.

Oviposition is not strictly associated with a suitable larval environment, but is more in the nature of a response to a tactile stimulus. Copulation appears to provide an essential stimulus for oviposition.

No evidence of parthenogenesis has been obtained and unfertilised females did not lay eggs.

The maximum oviposition observed was 3,171 ova by a hybrid Lucilia. This fly lived 94 days.

A total oviposition of 2,373 ova was observed in a L. sericata. Both parent flies lived 77 days.

The number of ova a fly can produce at one time is dependent on its size and thus on the amount of food obtained in the larval stage.

The sex-ratio for Lucilia is very close to 1 : 1. Starvation in the larval period did not have a marked effect on the sex-ratio.

It is possible to cross the two closely related species of Lucilia, and the cuprina characters appear to be dominant. It is unlikely that this cross occurs in the field.

Methods of breeding and manipulating Aëdes aegypti are described. Experiments on length of life were carried out with 534 mosquitos under eleven sets of conditions of atmospheric temperature and humidity. Also, 379 females were given an opportunity to suck blood under 11 sets of conditions. The following conclusions were reached :—

1. The length of life of starved mosquitos at 23°C. is very much dependent on humidity, but it cannot be directly related to saturation deficiency.

2. In these experiments there is no significant difference between the mean survivals of males and females, the former being generally longer.

3. The survival periods of fed and unfed females have a similar relation to humidity, the fed ones surviving the conditions for a longer period, irrespective of the date of feeding.

4. The effect of a change of temperature of 7°C. on the survival at 23°C. and 30°C. is much less than would be expected when the long survival period at 10°C. is considered.

5. In the absence of any efficient physiological adaptation for retarding loss of water, the females, possibly for this reason, seek a blood meal mainly in saturated air at the temperature of maximum activity.

(1) The history of Otiorrhynchus cribricollis in Australia is traced and records of its distribution in other countries are cited.

(2) Methods used in the experiments are described.

(3) The incubation period of the egg was found to vary between 14 and 37 days. The average was 22·3 days.

(4) The habits of the larva are described. Dyar's Law was applied to determine the number of instars, which was found to be 10.

(5) The normal duration of larval life is from May to October or a period of about 5 months.

(6) About 10 per cent. of the larvae aestivate through one summer. These have a larval life of about 17 months.

(7) Normal life of the adult is from November to April, about 5 months, but some (about 11 per cent.) hibernate through one winter and thus live 17 months.

(8) The adults feed in two seasonal periods separated by an interval of about 6 weeks, during which time they are inactive.

(9) The adults have been observed to feed upon 21 different plants, representing 12 different families.

(10) Most of the eggs are laid in the autumn, but a few are laid in the spring.

1. The biology and larval morphology of three Alysiine Braconids and one Chalcid, parasites of the pre-imaginal stages of some carrion-infesting Dipterous larvae, are described.

2. The mode of hibernation of the parasites is recorded.

3. The oviposition of Alysia manducator and Aphaereta minuta is discussed in detail, attention being drawn to the hitherto neglected sense-organs located in the tarsi of these two species and to their importance in the process of oviposition.

4. The differing responses of full-grown Lucilia sericata larvae to parasitism by Alysia manducator at high and low temperatures are suggested to be due to differences in the physiological states of the host larvae at these temperatures.

5. A comparative study of the three endoparasitic Alysiines suggests that Alysia manducator may have reached a state of endoparasitic life relatively later than the other species studied, or at least has not yet reached such an advanced stage of endoparasitic specialisation as have Aphaereta minuta and Aspilota nervosa.

6. The growth of the egg in Aphaereta minuta and Alysia manducator and of the larvae of Mormoniella vitripennis is discussed.

In the spring of 1932 the President of the International Locust Office at Damascus invited me to visit the main breeding areas of the Moroccan Locust (Dociostaurus maroccanus, Thunbg.) within the territories of the states adhering to that Office, i.e. Turkey, Syria and Iraq, in order to survey the local locust problem and to advise on the best general policy of locust control. The visit represented partly a continuation of the previous season's work in Western Anatolia (Uvarov, 1932) and concerned the great locust area which comprises the south-eastern vilayets of the Turkish Republic, the northern provinces of Syria and northern Iraq.

The voyage was planned to take place at the period when oviposition by locusts usually occurs, and about three weeks in the second half of May and early June were spent in actually touring the areas subject to regular locust invasions in Iraq and Syria. Unfortunately, no arrangements were made for including Southern Turkey in the tour and, therefore, an important section of the area remained unstudied.

While the choice of the period for the ecological investigations proved to be correct, the year was scarcely favourable for reaching very definite conclusions. Locust swarms were numerous and rather widely spread during at least two or three previous years, but the meteorological conditions of the early spring of 1932 were quite exceptional, owing to the practical absence of rains, which caused great mortality amongst young hoppers.

Egg-pods of the Red Locust (Nomadacris septemfasciata, Serv.) deposited on the 17th January 1933 at Mazabuka, Northern Rhodesia, were kindly sent by air-mail to the Imperial Institute of Entomology by Mr. W. Allan. On their arrival 14 days later, the eggs were found to be perfectly healthy, apart from some having been damaged by pressure. Entire egg-pods, with the surrounding soil, were placed in wet sand in flower-pots and put in a glass cage. The temperature in the cage was kept at 100°F. during the day and 80°F. during the night, but that of the sand was probably somewhat lower. Hoppers began to hatch on the 2nd of March and were kept at the same temperatures, with a humidity as near the saturation point as could be maintained. The first adult appeared on 8th April, and the majority of hoppers became adult by the 18th of April, six and a half weeks after hatching. Owing mainly to cannibalistic habits of the hoppers, only about 40 adults were obtained.

It was obviously impossible to plan any serious experiments with such a small number of locusts available, without risking the loss of the entire stock, and it was decided to use them for a preliminary experimental test of the conditions necessary for the sexual maturation. This particular problem is of great practical importance and no data bearing on it were available.

(1) Asterolecanium coffeae occurs in all the British East African Dependencies and has been the cause of much loss in certain low-lying coffee areas of Kenya. On the crop-bearing parts of the coffee tree (Coffea arabica) it inflicts injuries of an irreparable nature, and a heavy infestation is extremely difficult to eradicate.

(2) A. coffeae is oviparous, and after deposition the eggs pass through a period of incubation within the “ test ” of the mother. The fecundity of the female is low compared with that of the common Lecaniine scales and mealybugs which infest coffee in Kenya. The average number of eggs produced by a single female is about 50. The male is extremely rare and fertilisation of the female must be a very infrequent occurrence.

(3) The duration of development of the female from egg to egg varies between 60 and 70 days. The duration of the first stadium varies from 7 to 12 days, and that of the second stadium from 18 to 25 days. The pre-oviposition period is 28 days.

(4) The various stages of the female scale are described.

(5) Only one primary parasite of A. coffeae was obtained, namely, Metaphycus lounsburyi, How., and it is frequently abundant towards the close of the dry season, but its effectiveness is nearly always considerably reduced, by the high prevalence of a secondary parasite, Perissopterus busckii, How. A Coccinellid, Chilocorus angolensis, Crotch, preys upon the mobile first instar forms.

(6) A. coffeae is not a honeydew secreting Coccid and is entirely ignored by ants.

The following species of mealybugs have been collected from Coffea arabica in Kenya Colony :—

Pseudococcus lilacinus, Ckll.

Pseudococcus citri, Risso.

Pseudococcus simulator, sp. n.

Pseudococcus virgatus, Ckll.

Pseudococcus perniciosus, Newst. & Willc.

Pseudococcus longispinus, Targ.

It is possible that additional species may be collected, especially from the coffee districts of Western Kenya, which are very distant from Nairobi, but undiscovered species, if they exist, can be little more than entomological rarities.