The rapid spread of the single host arsenic-resistant blue tick, B. decoloratus, a transmitter of piroplasmosis and anaplasmosis, seriously affected a large and important cattle ranching area in South Africa.

Biological tests, using the laboratory technique described in an earlier paper, enabled the most effective “Gammexane” preparations to be rapidly selected from numbers of experimental dips. The technique was also employed as a supplement to chemical analyses of dip wash samples where only the total hexachlorocyclohexane and not gamma isomer was estimated. Twenty-thousand adult female ticks were used in these in vitro tests. Oil emulsions seemed more active than dispersible powders or pastes, but all tests indicated that 50 parts per million “Gammexane” should satisfactorily control the tick in the field.

Laboratory tests with larvae of the blue tick showed that “Gammexane” had a persistent action and was very toxic to this stage of the tick. Excellent control oflarval ticks could be anticipated in the field.

In vitro tests indicated that “Gammexane” was effective against the two- and three-host ticks, R. evertsi, R. appendiculatus, A. hebraeum, H. silacea and Hyalomma spp., but hand dressing and shorter dipping intervals might be necessary to control these ticks in the field. The sheep paralysis tick, I. pilosus, seemed to be resistant to “Gammexane” but was readily killed by arsenic.

Railway trains running through tsetse-infested country between Mombasa and Nairobi in Kenya Colony carry G. longipennis, G. pcdlidipes and G. brevipalpis on to stock-farming areas beyond the natural limit of the fly belt, thus being largely responsible for outbreaks of animal trypanosomiasis and a reluctance on the part of European, Asian and African settlers to develop the land, affected by this form of fly dispersal, to its full capacity.

The country through which the trains travel is described together with an account of a survey of the fly distribution.

Tabulated figures are given of the monthly totals of tsetses collected from passenger and goods trains by teams of fly boys posted at Emali and Sultan Hamud railway stations about 17 and 25 miles respectively outside the fly belt towards Nairobi More than 24,000 flies were collected over a period of one year and many, not collected by the de-flying teams, were carried up-country even as far as Nairobi, 101 miles from the fly belt.

Tsetses were collected from inside passenger trains, but very much larger numberswere taken from the outer surfaces and undercarriages of goods trucks.

Reference is also made to the rôle of motor traffic, especially when in convoy in the dispersal of tsetses.

The incidence of animal trypanosomiasis along the line of the railway is dealt with and the association of the disease with tsetses carried by trains is supported by results of laboratory experiments on the transmissibility of Trypanosoma congolense, T. vivax and T. brucei by the three species of flies concerned.

Bush-clearing on stock farms outside the fly belt will not protect the cattle from infection carried by flies brought by trains but bush-clearing in specified localities of fly concentration in the infested country is recommended as a measure to reduce the numbers now attracted to trains. It is considered that the spraying of trains will bring considerable relief to farmers ; but, so far, no suitable spraying apparatus has been devised nor has a reasonably cheap insecticide been found for this purpose.

Six species of Cryptolestes that occur in stored products (C. ferrugineus (Steph.), C. capensis (Waltl), G. pusillus (Schönh.), C. turcicus (Grouv.), C. pusilloides (Steel & Howe) and C. ugandae Steel & Howe) showed different susceptibilities to fumigation with methyl bromide at 30°C. and 80 per cent. relative humidity. The susceptibilities were partly correlated with morphological and bionomic differences between the species: C. ferrugineus was the least susceptible.

The potato bug, Closterotomus norwegicus (Gmelin) (Hemiptera: Miridae) is an introduced pest of lucerne, white clover and lotus seed crops in New Zealand and a key pest of pistachios in California, USA. Efforts were made to identify potential biological control agents of C. norwegicus in Europe. A total of eight parasitoids, including six primary parasitoids from the genus Peristenus (Hymenoptera: Braconidae) and two hyperparasitoids from the genus Mesochorus (Hymenoptera: Ichneumonidae), were reared from C. norwegicus nymphs collected in various habitats in northern Germany. With a proportion of more than 85% of all C. norwegicus parasitoids, Peristenus closterotomae (Hymenoptera: Braconidae), a new species, was the most dominant parasitoid, whereas other parasitoid species only occurred sporadically. Peristenus closterotomae did not fit in the keys to any described species and is described as new to science. Parasitism caused by P. closterotomae was on average 24% (maximum 77%). To assess the host specificity of parasitoids associated with C. norwegicus, the parasitoid complexes of various Miridae occurring simultaneously with C. norwegicus were studied. Peristenus closterotomae was frequently reared from Calocoris affinis (Herrich-Schaeffer), and a few specimens were reared from Calocoris roseomaculatus (De Geer) and the meadow plant bug, Leptopterna dolobrata (Linnaeus) (all Hemiptera: Miridae). The remaining primary parasitoids associated with C. norwegicus were found to be dominant in hosts other than C. norwegicus. Whether nymphal parasitoids may potentially be used in a classical biological control initiative against the potato bug in countries where it is introduced and considered to be a pest is discussed.

The importance of the reaction of mosquito breeding water was established by MacGregor in 1921, and since then observations have been reported from various parts of the world. In the original paper MacGregor showed that, in the laboratory, three species of English mosquitos could survive an alkalinity of pH 9·6 and died in acid water of pH 4·4, while two other species developed in pH 4·4. Later, in Mauritius, he found the local Anophelines in water ranging from pH 9·5 to pH 8·4 and rarely in places giving the reading pH 7·4 ; and maintained that the reaction of any water there was a reliable index of the presence of Anopheline larvae. Senior White, in Ceylon, found the local Anophelines in water with readings from pH 5·8 to pH 8·6 usually, and decided that on the whole the local Culicines had a more restricted range. Buxton, in Palestine, found six species of Anopheles in water varying from pH 9·2 to pH 7·4, and of these only one occurred in water less alkaline than pH 8. He notes that Nablus, where the water supply is unusually acid for Palestine (pH 7 to 7·5), is free from malaria.

The subgenus Synphlebotomus of Phlebotomus is reviewed, and an illustrated key is given for the six African and two non-African species. The status of P. rossi De Meillon & Lavoipierre, the suspected vector of dermal leishmaniasis among animals in South West Africa, is revised, and it is described and illustrated in detail.

Catches of Glossina palpalis palpalis (R.-D.) and G. tachinoides Westw. at high and low densities with hand-nets, biconical traps and an electric back-pack trap in Nigeria indicate that both types of trap are inferior to hand catching for routine checks of G. palpalis and G. tachinoides populations. Hand catching is recommended as being most suitable for large-scale surveys, assessment of control following insecticide spraying and classical fly-rounds. The biconical trap is recommended for use in experiments of a limited size, monitoring of fly populations on livestock ranches and around Villages, and for capturing flies for dissection. The electric trap is recommended for use in sampling flies in areas of medium and high density and possibly for blood-meal identification. Some blood-meals of G. palpalis were identified.

The amidinohydrazone insecticide hydramethylnon, exhibited delayed toxicity to workers of Reticulitermes santonensis Feytaud and Microtermes lepidus Sjöstedt over a range of concentrations, with deaths starting two to six days after exposure. R. santonensis workers which had been exposed to hydramethylnon passed the insecticide to untreated termite workers, larvae and nymphs by trophallaxis. Laboratory colonies of R. santonensis exposed to hydramethylnon were killed completely within 20 days. The possible use of hydramethylnon impregnated baits for the control of subterranean termites is discussed.

Psyllaephagus yaseenisp.n. is described from Mexico, Central America and the Caribbean as a parsitoid of the nymphs of Heteropsylla cubana Crawford. The psyllid is a serious pest of Leucaena leucocephala, a shade tree and animal fodder in the tropics.

With the increasing demand for copra all over the world for the production of coconut oil, the cultivation of coconut palms has increased enormously during the last ten years in the Solomon Islands, New Britain, Papua, Samoa, and the New Hebrides, and large areas of virgin forest have been cleared and planted on regular scientific principles. In olden times most of the nuts were collected from the native plantations, where the palms were grown under almost wild forest conditions, arid were then more hardy and did not suffer to the same extent from insect pests as do the palms planted under modern conditions. It is probable that the increased food supply, represented in the fronds of the thousands of young coconut palms planted out, has been responsible for the enormous increase of a number of indigenous leafeating beetles, which, under the conditions previously prevailing, lived upon the wild coconut and other species of palms growing in the jungle. In addition to many insect pests allied to or identical with those known in Ceylon, India, and the Malay States, we have in these Eastern islands a number of leaf-destroyers in the small flattened beetles belonging to the family Hispidae. The larvae of these beetles feed either on the upper surface, or in the tissue of the leaf under the protection of which they finally pupate, so that one can sometimes obtain the whole life-history from the egg to the perfect insect in a single palm frond. The majority of these leaf beetles, which are causing so much damage in the coconut plantations, belong to the genus Protnecoiheca, Blanchard, and from what we know of the life-history of several species that have become serious pests, it is fairly safe to assume that the habits of all the species are similar.

The sensitivity of males and females of Glossina morsitans morsitans Westwood to the vapour phase of bisazir was tested in the laboratory in a moving air stream at temperatures ranging from 12 to 20°C. Similar tests were conducted in still air in closed systems. Bisazir was used in its granular form or absorbed onto silicone rubber or cellulose fibre surfaces from solution in dichloromethane. As a crystalline solid, it lost only 5% of its weight in a moving air stream over 12 days. However, even in relatively still air, bisazir absorbed onto cellulose fibre discs lost 70% of its weight at 20°C and 80% at 30°C in 24 days. Estimations of the amounts of bisazir present on a surface by weight difference were higher than those estimated by gas chromatographic analysis. Hence, in addition to being volatile, bisazir must be regarded as somewhat unstable. Nevertheless, sufficient active ingredient remained over a long enough period for it to be considered as a practical means of sterilizing tsetse in the field. Females were found more sensitive to bisazir than males, but exposure times required to produce total sterility in both sexes did not affect survival. Exposure times of only a few minutes were sufficient to induce a significant reduction in female fecundity or male fertility at 30–35°C, temperatures which might be expected under field conditions in a device to sterilize automatically tsetse attracted to traps in the field. The degree of sterility induced was permanent, and at these short exposure times the temperature had no effect on female fecundity.

Specimens of the interesting new species described herewith came into the hands of both authors of this paper at about the same time from the same source, and were determined by each as new to science. Each being in ignorance of the fact that the other had received specimens, both proceeded to describe it. Before either description was published, however, the duplication was discovered through correspondence, and the description has been made the subject of this joint paper. The type and allotype specimens are in the United States National Museum, but paratypes are in the British Museum as stated below.

The following paper is based upon material received by the British Museum (Natural History) since the publication of the author’s “Further Notes on the Tabanidae of Palestine”* All the specimens referred to, including the types of the two new species described in the following pages, have been presented to the National Collection by the Imperial Bureau of Entomology. With the exception of the type of the new Tabanus (see p. 428) and a few other specimens, all taken by Mr. O. Theodor, the entire series has been collected by Dr. P. A. Buxton, to whose contribution in the last number of this Bulletin† the reader is referred for important field-notes.

Recent investigations on the control of cheese mites in New Zealand have necessitated detailed biological studies of the species concerned. Experiments have been carried out on the physical ecology of the species, Tyrophagus longior, Gerv., Tyrolichus casei, Oudm. [Tyroglyphus siro, auct.] and Tyroglyphus farinae, Degeer. A technique has been developed whereby, under controlled temperature and humidity conditions, individual developmental records may be readily obtained for all stages of the life-cycle. This technique is one that may be modified for similar studies on small insects, such as Thysanoptera, Collembola, etc.

A southern population (S) from Xiushui County (29°1′N, 114°4′E) and a northern population (N) from Shenyang city (41°48′N, 123°23′E) of the cabbage beetle, Colaphellus bowringi vary greatly in their life-history traits, and may serve as an excellent model with which to study the inheritance of life-history traits. In the present study, we performed intraspecific hybridization using the two populations, comparing the key life-history traits (fecundity, development time, body weight, growth rate, and sexual size dimorphism (SDD)) between the two populations (S♀ × S♂ and N♀ × N♂) and their two hybrid populations (S♀ × N♂ and N♀ × S♂ populations) at 19, 22, 25, and 28°C. Our results showed that there were significant differences in life-history traits between the two parental populations, with the S population having a significantly higher fecundity, shorter larval development time, larger body weight, higher growth rate, and greater weight loss during metamorphosis than the N population at almost all temperatures. However, these life-history traits in the two hybrid populations were intermediate between those of their parents. The life-history traits in the S × N and N × S populations more closely resembled those of the maternal S population and N population, respectively, showing maternal effects. Weight loss for both sexes was highest in the S population, followed by the S × N, N × S, and N populations at all temperatures, suggesting that larger pupae lost more weight during metamorphosis. The changes in SSD with temperature were similar between the S and the S × N populations and between the N and the N × S populations, also suggesting a maternal effect. Overall, our results showed no drastic effect of hybridization on C. bowringi, being neither negative (hybrid inferiority) nor positive (heterosis). Rather, the phenotypes of hybrids were intermediate between the phenotypes of their parents.

This part of the study of the garden chafer, Phyllopertha horticola (L.), in the English Lake District covers the flight seasons 1948–1952. Annual sex ratios in the population of pupae (just before ecdysis to adult) ranged from 34·6 to 46·9 per cent. females.

The flight season begins with the emergence of some adult males upon the sward. If the weather continues favourable, the earliest females appear on the second or third day of the season. Unsuitable weather delayed the advent of females until the sixth day in two seasons. In a homogeneous population, primary emergence is complete in just under a fortnight, at the end of which time numbers of beetles seen on the grass sward are at their peak. Phase 1, swarming over the sward, continues, with dwindling numbers, for just over a week more (overlapping Phase 2, swarming on the bracken).

The female/male ratio rises throughout Phase 1 except for a tendency to fall in the last day or two. But generally for most and sometimes the whole of Phase 1, the proportion of females above ground is far below the true population ratio. This is partly because population emergence in the female is 1–2 days behind emergence in the male; but much more because after primary emergence the male is fully involved in above-ground activity every day until the beginning of Phase 2 or end of Phase 1 (depending on whether he emerges earlier or later), while the female is not.

In the same way, there are no females present on the bracken until after the first day of Phase 2, but the proportion of females rises more quickly and to a higher level than in Phase 1. By the middle of Phase 2, the proportion is close to the true population ratio. Since males are now confined to the bracken, this means that mass oviposition is more or less complete. During the last week of the season the female proportion rises steeply. This is because females live a few days longer than males besides being 1–2 days behind males in their original emergence.

After primary emergence, the average female lives about a fortnight, the male rather less. Approximately the first half of adult life is spent in the grass sward area, the second half on the surrounding bracken (or hedges or trees).

As Phase 1 proceeds, the pairing rate of females decreases. This is partly because the proportion of males is falling and therefore fewer males are available to search for each female over the grass sward, and partly because of a change in mating behaviour of the female as she ages. On the other hand, pairing rate is at its highest (average 82%, maximum 95%, of available females) in Phase 2 when the proportion of males is at its minimum (actually the true proportion in the population). This is because on the bracken the beetles are confined to a much smaller area than on the grass and therefore males find females more readily.

In flying weather, the proportion of beetles in the air at any moment is at best no more than about 70 per cent.; usually it is less than 50 per cent. On the whole males are very much more given to flying than females.

Tomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive tomato pests worldwide. We tested quantity and quality of tomato fruits after simultaneous use of two biological control agents, the predatory mirid bug Nesidiocoris tenuis (Reuter) and the egg parasitoid Trichogramma brassicae Bezdenko against TLM. We varied the timing of predator releases (before or after pest establishment) and the number of parasitoids released (ten or 30 females per week per m2). The highest number of fruits per cage, percentage of undamaged fruits, total yield weight, and undamaged yield weight were all obtained with predator-in-first treatments, with or without parasitoid releases. Furthermore, measures of fruit quality were also highest in predator-in-first treatments, including, highest percentage of water, greatest proportional fresh weight of carbohydrates, most lycopene, most β-carotene, most flavonoids, and highest total chlorophyll. Thus, our findings support a predator-in-first augmentation approach for management of TLM.

The first puparium of Glossina morsitans found in nature, as mentioned in Mr. E. E. Austen's recently published “Handbook of the Tsetse-Flies,” was taken in November, 1910, from the collection of mould and humus between the roots of a large tree (Ficus sp.) near the Gorai river below the Escarpment in the Lomagundi District, Southern Rhodesia. The tree is situated about 60 to 70 yards from the actual bank of the river, as it runs at present. It is in reality growing on what was the old bank of the river, which is changing its bed gradually owing to the soft nature of the ground through which it flows. At the time of the visit “fly” was abundant in the shade of the trees bordering the river, the sandy bed of which then contained no water on the surface, the nearest open water being twelve to fifteen miles away in the Hunyani river. It was thought at the time that this was the only pupa-case secured, and a search all along the river bank produced no others. A number of empty pupa-cases of other Diptera and Lepidoptera were, however, placed in a corked phial and labelled, and on going over these later in the laboratory, the anal end of a second tsetse pupa-case was found amongst them, showing the characteristic protuberances. This spot was again visited in April, 1911, and under the same tree five more empty puparia were found, but, as before, the most diligent search elsewhere failed to produce any more. A photograph of the tree taken in November is reproduced (Pl. XVII, fig. 2).

A method is described for the large-scale rearing of Pseudotheraptus wayi Brown, the Coreid causing immature nutfall of coconuts in East Africa.

Adults were kept in cages with sides of thick white drill and wire-gauze, in an outdoor insectary at Matuga, near Mombasa, Kenya, and were provided with freshly collected fallen nutlets from which the bracts had been removed. Eggs were normally laid on the walls of the cage. The nutlets were replaced every two days, and all newly hatched nymphs removed and placed in other cages supplied with fresh nutlets every second day. There was some mortality in the first- and second-instar nymphs due to the handling entailed when nutlets were replaced, but in the later nymphal stages it was very low. Under these rearing conditions, the life-cycle from egg to adult was completed in from 35 to 40 days.

The toxicities to Pseudotheraptus of dieldrin, DDT, γ BHC, malathion and pyrethrins in a solvent were compared by topical application of measured-drop doses from an Agla micrometer syringe in a range of five concentrations (except for DDT, where eight concentrations were used). The mortality counts at 72 hr. were taken as the measure of toxicity.

Analysis of the log dosage/probit regression lines indicated that dieldrin was markedly more toxic than DDT to Pseudotheraptus, and that the toxicity to this insect of pyrethrins was of a very low order.

In a supplementary experiment to determine whether the addition of resin improved the toxicity of DDT when applied topically, batches of adults were treated with measured drops of a solution of p, p'DDT (0·5 per cent, for females, 0·25 per cent, for males) and others with the same concentrations of DDT to which coumarone indene resin at one-tenth of the DDT content had been added. The toxicity of the DDT was not enhanced.