Linnaeus (1746) described a black aphis which he found on Rumex sp. and called it Aphis rumicis. Fabricius (1794) described a black aphis “ Aphis rumicis,” found “in Rumice acuto” and mentioned pale antennae and tibiae. Risso (1826) recorded a species, Doralis rumicis, Leach, found in the Mediterranean region, but did not describe it. Koch (1857) recorded Aphis rumicis, L., from Rumex crispus, feeding chiefly on the stems and flower-stalks. This aphis is also frequently found on thistles and beans. The apterous female has black antennae, white only at the base of the long “ fourth joint.” The wing-pads and thorax of the alate nymphs are olive-green. Kaltenbach (1874) described black Aphids developing from eggs on dock, and having a second winged generation which settles on beans, thistles, Chenopodium sp., and other plants. He observed that the Aphid colonies are on the leaves and flower-stalks. Buckton (1879) gave an illustrated account of a black aphis, Aphis rumicis, L., which has a large number of food-plants including Rumex crispus, Carduus lanceolalus, and broad bean, with furze as its winter host. He noticed the presence of large white flecks on the “pupae.”

Further evidence is provided to show that the head of the desert locust is the most vulnerable body region to the toxic action of malathion (and malaoxon). The circulatory system is shown to play an important part in determining the toxicity of the insecticide by taking it towards or away from the sensitive areas. The rates of absorption, distribution and excretion of 3H-malathion for different applications are given.

The effects of temperature and humidity on the development of Oligonychus coffeae (Nietner) were studied by exposing the various stages of the mite to air in equilibrium with saturated solutions of appropriate salts in containers within thermostatically controlled cabinets. Adults and early stages were maintained on fresh tea shoots.

The pre-oviposition, oviposition and post-oviposition periods of adult females at 75–80% relative varied inversely with temperature, and averaged, respectively, 0.8, 5.9 and 1.4 days at 32° and 2.3, 30.6 and 2.0 days at 20°C. The mean number of eggs laid per female likewise varied inversely with temperature, from 12.0 at 32°C at 32° to 107.3 at 20°C.

No eggs hatched when incubated at 34°C., irrespective of humidity, or at 17% R.H., irrespective of temperature. Optimum conditions for incubation (those affording over 90% hatch) were provied by a combination of temperatures and relative humidities within the ranges 20–30°C. and 49–94%. When eggs were exposed daily for five days to temperatures of 37 or 40° for six hours at 72–94% R.H. and then transferred to room conditions (24–32°C., 64–88% R.H.), the percentage of eggs hatching was reduced from 94.7 (room conditions) to about 75 or 5–12, respectively.

The mean incubation period of eggs varied from 3.9 days at 32° to 10.8 at 20°C., and the mean duratio of the combined larval and nymphal stages from 4.9 days at 30° to 8.7 at 20°C. At 32°C., larval mortality was very high.

A survey of Simuliidae in three areas of Pakistan in May and June 1963 yielded 845 pupae, some larvae and 143 captured adults, bringing the number of species for the area from seven to 31. Three species are described as new, and notes are given on other new but unnamed species. A key is given, based mainly on pupae. The previously unknown male, pupa and larva of Simulium indicum Becher are described, together with a new subgenus, Himalayum, for this species. It was breeding on vegetation in a fast river, occurring at 700–1450 m above sea level in spring and autumn, and at higher altitudes in summer. Pupae of S. mediterraneum were found in polluted water. Three species were phoretic, and several were found on or near man or domestic animals.

In a recent paper by the writer (Bull. Ent. Res., xxi, 1930, pp. 201–256) it was shown that the apparent fly density varied according to season. It has now been found that these seasonal variations in the fly density can be correlated with the evaporation rate.

The accompanying graph shows the mean monthly evaporation rate, and the mean monthly apparent fly density. The evaporation rate figures have been obtained from a Livingston atmometer at the Kikori Entomological Station. The fly figures have been taken from the North-East Kikori Round, because this fly-round is not subjected to large game movements and hence is considered to be the best for demonstrating the correlation between fly density and season.

The graph deals with a period of eighteen months, and it is clear that a relationship does exist between the two curves.

In June and July 1929, the fly density was at its maximum. Hence it is reasonable to postulate that, at this time, the evaporation rate was suited to the requirements of the fly community.

The susceptibility of various mosquitos to DDT, dieldrin and BHC has been studied. Adult females were exposed in small tubes lined with filter papers impregnated with insecticide-oil solutions. Larvae were exposed to insecticideacetone suspensions in water.

Adult mosquitos tested in London showed no striking differences in susceptibility to DDT, though the median lethal concentration (MLC) of Culex pipiens molestus Forsk. (1·6 per cent.) was greater than the MLC of Aëdes aegypti (L.) (0·9), Anopheles maculipennis var. atroparvusvan Thiel (1·0), or A. quadrimaculatus Say (·7). C. p. molestus and Aë. aegypti showed the same order of susceptibility to dieldrin and BHC, with Anopheles m. atroparvus more susceptible to both insecticides.

Eight South American geographical populations of the parasitoid Microctonus hyperodae Loan were collected in South America (Argentina, Brazil, Chile and Uruguay) and released in New Zealand for biological control of the weevil Listronotus bonariensis (Kuschel), a pest of pasture grasses and cereals. DNA sequencing (16S, COI, 28S, ITS1, β-tubulin), RAPD, AFLP, microsatellite, SSCP and RFLP analyses were used to seek markers for discriminating between the South American populations. All of the South American populations were more homogeneous than expected. However, variation in microsatellites and 16S gene sequences corroborated morphological, allozyme and other phenotypic evidence of trans-Andes variation between the populations. The Chilean populations were the most genetically variable, while the variation present on the eastern side of the Andes mountains was a subset of that observed in Chile.

1. The damage done to coffee by Antestia lineaticollis, Stål, is shortly described and notes on its life-history are given.

2. It is parasitised in the egg-stage by two important species of Proctotrupoid parasites, the percentage of parasitism usually varying around 80 per cent. and in one case quoted being as high as 91 per cent.

3. Of the control measures employed, contact-spraying has not proved satisfactory; hand-picking of the bugs and egg-clusters and liberation of the parasites are widely practised and, though troublesome and expensive, are of considerable value; another method of value and widespread adoption has been called the “poison-baitspray” method. This is described in detail; it consists in the application of a stomach-poison in the form of a solution of sodium arsenite and sugar to the tree by spraying. Laboratory observations show that the insect imbibes the poisoned solution by lifting the proboscis into small drops on the leaf surface, and there is a definite kill due to the use of this poison.

4. In Kenya, its use commercially, while often of proved value, has not been invariably successful. Experiments showed that the egg parasites of the bug were strongly attracted by the poison spray and quickly died after feeding on it. It is suggested that this may be the cause of some of the unsuccessful results.

Nine types of plastic ear tags impregnated with organophosphorus, amidine or synthetic pyrethroid compounds were applied to both ears of groups of five Maasai zebu cattle in Narok District, Kenya, and grazed together with five untagged cattle to which no acaricides were applied. Most of the tag types gave highly efficient control of Rhipicephalus appendiculatus Neumann attaching to the head and ears of the cattle, which lasted up to 160 days after application and often completely prevented tick engorgement. All the chemical groups were effective. The most effective tag was a combination of amitraz and permethrin which gave better control than either chemical on its own. Control of Boophilus decoloratus (Koch), Amblyomma cohaerens Dönitz, A. variegatum (F.) and R. evertsi evertsi Neumann attaching to the bodies of cattle was less effective, although most of the tags exerted some effect. Rainfall appeared to reduce the degree of control by the tags. A role for such impregnated ear tags for the control of cattle ticks in Africa is suggested.

The most obvious effect of sleeping sickness is depopulation, which can be occasioned directly, through mortality from the disease, and indirectly, through a lowering of the reproductive rate of a community because of induced sterility and increased infant mortality.

The problem was studied in the north of the Gold Coast and the neighbouring French Upper Volta Territory, where severe epidemics have occurred, in localised form since at least the middle of last century, and in widespread form during the past 30 years. The vectors have been the riverine tsetse Glossina palpalis and G.tachinoides.

A close correlation was found to exist between the incidence of sleeping sickness and the population trend with a marked depopulating effect coming in at infection rates above 3 per cent. It was also found that both the rates of trypanosomiasis infection and the extent of depopulation showed closely similar relationships to the proximity of affected villages to the nearest flybelt.

The larvae and pupae of the following Lepidoptera, all of which are of economic importance in Mauritius and most of them elsewhere also, are described:—

The Agrotids, Sesamia calamistis Hamps. and S. inferens (Wlk.); the Crambids, Proceras sacchariphagus Boj. and P. indicus Kapur (larva only); and the Olethreutids, Argyroploce schistaceana (Snell.), A. leucotreta Meyr., Cryptophlebia peltastica (Meyr.) and C. williamsi Bradley.

The insecticidal potencies of γ-BHC and a range of chlorinated cyclodiene compounds have been measured for normal and resistant strains of both Musca domestica L. and Lucilia cuprina (Wied.). Apart from minor discrepancies, the relative potencies presented similar pictures in the two species, and the resistance spectra were also similar.

Moderate to high insecticidal potency is shown by a variety of compounds with a chlorinated bicyclo-heptene nucleus in the molecule, including Diels-Alder condensation products and chlorinated camphenes. Various additions and sub-stituents on the nucleus affect the potency quantitatively but not qualitatively. In contrast, γ-BHC is almost unique among poly-halogenated cyclohexanes.

When resistance develops to any of the chlorinated cyclodiene compounds, it invariably extends to all others and to γ-BHC and chlorinated adamantane. The resistance level, in most cases, is proportional to the original potency of the compound; this is apparently because resistance is usually complete, so that the more toxic compounds have more to lose. There are, however, a few puzzling exceptions.

The consistency of the cross-resistance spectrum to all members of the group implies a common defence mechanism. This suggests a common mode of toxic action, resistance being due to insensitivity at the site. A common mode of action for the cyclodiene series is understandable; the anomalies are γ-BHC and chlorinated adamantane. Their conformity with the cyclodiene insecticides was investigated by the following observations with normal insects: (a) signs of poisoning; (b) relative potency to different species; (c) tests with mixtures. The general conclusions were not unfavourable to the hypothesis of a common mode of action, though secondary features of the intoxication process somewhat complicated the results.

Dysdercus superstitiosus (F.) is capable of utilising a much wider range of food-plants than was previously supposed, and is able to complete a full breeding cycle on the several diets other than cotton. This has been demonstrated by rearing and breeding adults and nymphs in the laboratory, in Uganda, on selected food material, e.g., Sorghum vulgare, Pennisetum typhoides, Zea mays and Vigna unguiculata, immature seeds of each being used. Diets other than mature cotton seeds are less suitable for breeding, as judged by fecundity of females and development of nymphs, but the influence of nymphal diet on adult fecundity is not consistent. Females reared on sorghum are smaller than those reared on cotton seed and they may lay fewer eggs.

There is an indication that varieties of sorghum may differ in their suitability for producing maximum fecundity and fertility. Those varieties to which the stainer exhibits a predisposition in the field may not be the most suitable.

When adults are fed on cotton bolls of ages 1–10 weeks, the fecundity of females, and the rate of egg-production increase with increasing age of boll, and the preoviposition period decreases.

Stored cotton seed may be less suitable for egg-production than freshly harvested seed cotton.

Extraction of oil from cotton seed with petroleum ether does not wholly impair the fecundity rate of females fed on the seed, but may reduce the fertility and nymphal survival in the first instar.

A diet of cotton seed, heat treated at 150–190°C. for one hour, reduces the fecundity in the females, possibly by destroying the accessary food factors. Nymphal survival is possible on such treated seed, but not when thus heated for two hours at or above 150°C.

Twenty-three species of Metaphycus from Africa are recognized in this paper, and of these, seventeen are described as new. The holotypes and allotypes of all new species are to be deposited in the British Museum and paratypes in the United States National Museum.

The foregoing observations and experimental work clearly indicate that the bulb mite, Rhizoglyphus echinopus, is not a primary pest of the narcissus. At the same time there is every indication that the mite does bring about the destruction of bulbs originally damaged by other organisms or by mechanical means, which would normally recover from their original injuries. Further, the mites can undoubtedly carry fungus spores from bulb to bulb. It is therefore very desirable that every effort should be made to reduce the mite population in bulb-growing areas to a minimum. This can be effected by careful attention to the points enumerated under the heading of control measures.

A model has been developed which estimates the egg and nymphal development periods of the desert locust Schistocerca gregaria (Forskål). The model uses long-term monthly mean temperatures from a number of weather stations in the desert locust area. The computer program calculates the daily mean temperature and the daily related amount of development. It then accumulates the percentage of development estimated on successive days until the total reaches or exceeds 100. The model can be started on any day of the year at any given development stage and it can calculate development backwards in time as well as forwards. The model should be a useful aid in forecasting desert locust population developments and for the planning of surveys.

A preliminary account of the main differentiating characters of Saissetia miranda(Cockerell & Parrott), S. neglecta De Lotto and S. oleae (Olivier) is given, together with notes on their hosts and distribution in Central and North America. Three forms of S. oleae occur in California.

1. The survey of Diatraea spp. in their primitive habitats has been extended to cover the interior Guiana plateau, the Rio Branco, the lower Rio Negro and the lower Amazon.

2. The greatest practical result has been the discovery and introduction into British Guiana of the Amazon fly parasite (Metagonistylum minense) of D. saccharalis.

3. The most interesting ecological result was the finding of several Diatraea spp. as original members of a true savannah association.

4. The twelve species considered are grouped as forest, riparian, savannah and domestic species.

5. The two forest species are D. bellifactella and D. brunnescens.

6. Riparian grass associations are developed over huge areas on the lower Amazon, where they may be divided roughly into three main zones, dominated by Paspalum repens, Echinochloa polystachya and Paspalum fasciculatum, respectively.

7. The chief, and in fact only Diatraea of the first and second zones, is D. saccharalis, which is occasionally abundant.

8. The P. fasciculatum zone is colonised by D. amazonica and D. myersi.

9. The pure savannah species are D. canella, D. impersonatella, D. savannarum and D. cayennella.

10. D. lineolata is practically confined to maize, and no wild host-plants, either naturalised or indigenous, are known.

11. Five species attack cane, namely, saccharalis, busckella, impersonatella, canella and albicrinella, and all except the latter are major pests over considerable areas.

During the last decades, an increasing number of predators were found to use specific prey pheromones as chemical cues. Beyond its ecological relevance, this knowledge has practical applications on insect conservation and pest control. In this study, we present first evidence that two species of the family Dasytidae (Coleoptera) Aplocnemus brevis Rosenhauer and A. raymondi Sainte-Claire Deville use the sex pheromone of the pine bast scale Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae) as kairomone to locate this prey. The feeding habits and biology of Aplocnemus species are practically unknown. In the laboratory, the adults of Aplocnemus sp. accepted M. feytaudi egg masses as food source as well as other diets. Females represented more than 90% of Aplocnemus sp. attracted to the pheromone lures. We believe that females use this olfactory cue to locate suitable places for oviposition and that larvae are the predators of Matsucoccus. This study further demonstrates that the response to the kairomone elicited short prey searching times, about 23% of the individuals appeared less than 12 min after lure exposure, being consistent with the hypothesis of prey specialization. Habitat and geographical distribution predict an ancestral association of A. brevis with M. feytaudi and of A. raymondi with M. pini. Nevertheless, a recent prey shift of A. raymondi to the invasive M. feytaudi in Corsica is in progress.