A cage colony of Anopheles pharoensis, Theo., was established in September, 1943. The methods used were mainly those described by Hackett in his paper on the Malaria Station in Tirana, read at the Amsterdam Malaria Congress in 1938.

The larvae of the Lymexylid beetle, Melittomma insulare Fairm., bore into the bases of coconut palms. Associated with them are micro-organisms which cause extensive rotting of the bole, particularly at ground-level, and this results in the palm falling.

During 1953–58, an attempt was made in Praslin Island, Seychelles, to obtain maximum control of this pest using paradichlorobenzene as a fumigant. At the time of this treatment, 77 per cent, of the 90,500 coconut palms in the island were infested. Of these, about five per cent, were felled as worthless mountainside palms and nine per cent, fell during or within a week of treatment.

In 1960 it was found that a further 15 per cent, of the palms had fallen and of those still standing 53 per cent, remained infested. The continuing high loss of palms after treatment was due to the closed, moist fumigation chambers within the trunks encouraging the spread of rot, coupled with an incomplete kill of larvae.

A new method of treatment is described in which the necrotic wood is excised and a formulation of coal tar creosote and coal tar liberally applied. Praslin Island was retreated, using this tar method, and a plan to treat all the coconut palms in Mahé, the main island of the group, was subsequently commenced. Losses of palms during and within a week of treatment have been reduced to less than one per cent., and results are quoted which show that a single treatment can reduce a serious infestation in which 80 per cent, of palms are more or less heavily attacked to one in which only 18 per cent, of the palms are attacked and, on average, contain only five larvae. The treatment ensures that the entrances to the tunnels of these are exposed to view, and accordingly the surviving larvae can easily be killed.

The relative size of the compound eye constitutes a good phase character in Locusta migratoria migratorioides, the ratio E/D (length of elytra to the maximum vertical diameter of eye) being over 15 in the males and about 16 in females of the gregarious phase, as against about 13 in the males and about 14·5 in the females of the solitary phase.

During the testing of finely ground pyrethrum flowers as an insecticide for the control of Antestia lineaticollis, Stål, in coffee trees, it was noticed that the various instars showed different percentage death rates under the same conditions. The experiment which is dealt with here was primarily designed to discover the minimum effective dose of powder per tree, and was carried out as follows.

A block of 1,700 coffee trees was divided into seventeen square plots each containing 100 trees. Nine of these plots were treated with pyrethrum powder at rates varying from about 1 gram to 5 grams per tree; all the trees in the same plot receiving the same amount of powder. Two days later 36 trees from each of these plots, comprising all the trees from the centre of the plots (the two outer rows of each plot not being used in case migration of the Antestia should have taken place from the adjoining control plots) were heavily drenched with a strong kerosene extract of pyrethrum in order to bring down all the Antestia remaining on the trees; these Antestia were collected separately for each tree, sorted into instars and recorded. This method of testing is described fully by Le Pelley (1934).

In each of the eight control plots five trees selected at random were drenched with the kerosene extract of pyrethrum and the Antestia obtained were recorded in the same way. It was found that the average number per tree of Antestia and of each instar present in each of these control plots, which were themselves evenly distributed through the whole block, was practically constant. It was therefore assumed that the numbers of Antestia and of each instar was the same for the plots treated with pyrethrum prior to this treatment, and the number of each instar found on the trees after treatment subtracted from this figure represented the number which had been killed by the pyrethrum powder.

The present paper reports on a few Copeognatha received by the author for determination from the Imperial Bureau of Entomology, for which I am very much indebted to the kindness of the Director, Dr. Guy A. K. Marshall. Unfortunately all the specimens were dried and carded, so that it is impossible in some cases to give as full descriptions as are desirable for complete characterisation of the species, and as would have been done if there had been alcohol material at my disposal. Never-theless, it seems desirable to record all the species before me, as nothing has been known hitherto regarding the Copeognath fauna of the Fiji Islands.

The Oyani Valley is in the South Kavirondo native reserve of Kenya Colony. The river from which the valley takes its name rises in the Kilgorris groups of hills in and near the south-west corner of the Masai Reserve. The Oyani enters South Kavirondo at a point about 1°0' South by 30°35' East; it flows in a general north-westerly direction through the Kanyamkago location and joins the Kuja River about eighteen miles above the junction of the Kuja and the Gori Rivers.

Genetic methods to eliminate females prior to releasing sexually sterilized males in sterile insect technique programmes generally involve the translocation onto the Y chromosome of a readily selectable gene (here designated F). However, such strains often show instability with regard to sexual dimorphism. Concerted attempts to determine the most probable causes of such instability have rarely been successful, and appropriate countermeasures have generally not been implemented. We have developed a computer model which simulates the progression of instability in such strains. Here we simulate the effects of contamination in association with a range of genetic and biological parameters and assess the patterns and rates of progression of the ensuing instability. A single event of contamination alone was found to contribute relatively little to the progression of instability and invariably resulted in an equilibrium within the population. However, strong effects were produced by reduced fitness and mating competitiveness of both the f/f genotype and the translocation carriers, a reduction in the parameters involving the f/f genotype resulting in the virtual elimination of f/f, while a reduction in the translocation parameters had the opposite effect of virtually eliminating the F/ – phenotype. The sex ratio was affected only by a change in the relative fitness of the f/f genotype and the translocation. Several characteristic patterns contributed to distinguish clearly the effects of contamination from those of male recombination in unstable genetic sexing strains. With such knowledge appropriate measures may be taken to counter or alleviate the effects of instability in mass reared genetic sexing strains.

The author discusses the restriction of the genus Lepidosaphes to nine Holarctic species by Borchsenius and his assignment to other genera of most species previously placed in Lepidosaphes. These changes in generic assignment have affected the names of many species of economic importance. A key is presented to 13 genera allied to Lepidosaphes.

Two trials were undertaken in North Queensland dairy pastures to test cultural and chemical control of the funnel ant Aphaenogaster pythia Forel. Funnel antinfested pasture was ploughed, cultivated and replanted with several grass species and the legume Glycine javanica. Grazing with dairy cattle was controlled to maintain a dense sward. In untreated pasture where grazing was continuous, funnel ant mound building remained consistently high over the three-year period, but where grazing was regulated mound building was significantly reduced after three months and was negligible after three years. There was a significant inverse relationship between sward density and A. pythia mound numbers.

The quantitative study of Tyroglyphid populations involves their separation from the food material, for which existing methods are not entirely satisfactory A new method is described which depends on chemical treatment to remove the bulk of the flour. It is made quantitative and independent of moisture-content variation by application of the lycopodium-spore method of Wallis. A techniqul for determining the numbers of hatched and unhatched eggs per unit weight of flour is described. It provides information on the rate of increase or decreas in the number of eggs (natality rate per unit time) and hence on the ability the species to survive in a particular environment. The egg distribution in an undisturbed culture of Tyroglyphus farinae (Deg.) is found to be uneven. The technique is applied to the study of a population of Thyreophagus entomophagus (Lab.) under controlled conditions of temperature and humidity and the results discussed.

Galuzo (1941) in his ecological studies of the tick fauna in Kazakh S.S.R. states that the nymph of Hyalomma detritum, Schulze, overwinters on the host, that he is of the opinion that H. savignyi, Gerv., hibernates in the adult stage away from the host (in animal quarters or houses) and that he found hibernating nymphs of H. marginatum, Koch, in grass meadows.

In the course of field work carried out in Palestine during the winter 1945–16 only a few adult male and female ticks (some gorged) were found in the Jordan Valley and the Negeb, and none in the more temperate parts of the country.

The following descriptions axe based on material collected or reared by the author, together with specimens reared from host-plant material collected by colleagues to whom the author's thanks are due.

From the descriptions it will be further evident that the generic location of new species is still difficult, but this state of affairs can only be remedied by a monographic revision of the African Trypetidae. It is felt, however, that although the author has such a work in progress, it is not desirable to hurry publication. Delay is advisable, especially in view of the number of new species continually being found, and the frequent need for the formation of new genera.

Types of the new species are in the author's collection ; paratypes so far as available will be placed in the British Museum.

Larvae of the South African tephritid flies Mesoclanis polana Munro and M. magnipalpis Bezzi feed in the developing seeds of Chrysanthemoides monilifera. Host specificity evaluation using 109 plant species from 25 families indicated that complete development was restricted to their natural host C. monilifera. Minor feeding and limited development was detected on 18 species, but was of no ecological or economic significance. Mesoclanis polana and M. magnipalpis have been released in Australia and M. polana has established and dispersed widely. Mesoclanis magnipalpis has not yet become naturalized. Parasitism of M. polana in Australia by several species of Hymenoptera has been detected, but is not expected to limit the establishment and impact of these flies.

Numerous experiments have been performed to study the specific effect of hydrogen ion concentration, CO2 and oxygen content of water on may-fly larvae, which warrant the following conclusions :—

1. While hydrogen ion concentration is a factor of great significance, the carbon dioxide pressure is of greater importance and should afford a very reliable index of the suitability of water as a habitat for true aquatic insects.

2. May-fly larvae, and presumably other insects as well, can stand a very low concentration of oxygen, below 1·0 cc. per litre. In view of the fact that in nature oxygen content seldom goes down to such a low figure, insects should not, as a rule, die of lack of oxygen.

From conversations that the writer has had, it would appear that this thrips (identified by Mr. R. S. Bagnall as Heliothrips indicus, Bagn.) has been known on the Gezira cotton for about three years, and is popularly called “dry asal” in contradistinction to the work of the “asal fly” (Aphis sorghi, Theo.) The natives have been acquainted with this insect for some time. The reason suggested for the enormous damage done by itis that the cotton is too scattered, and it is stated that if cotton were cultivated in larger blocks, the thrips might be viewed with equanimity.

Omnivory involves numerous feeding relationships and a complex web of interactions. When using omnivores in biocontrol, these interactions need to be understood to maximize feeding on the target species and minimize non-target interactions. Dicyphus hesperus is used along with Encarsia formosa for biocontrol of whiteflies in greenhouse tomato crops. Dicyphus hesperus is a generalist omnivore which feeds on all components of the system. To quantify these interactions, stable isotope analysis was used to identify trophic position with nitrogen isotopes (δ15N) and plant sources with carbon isotopes (δ13C). Feeding trials were used to establish baseline isotopic data for D. hesperus and their diet, including Verbascum thapsus, an alternative plant food. Cage trials were used to monitor population abundances and the isotopic signature of D. hesperus. In feeding trials, D. hesperus were enriched relative to their food, suggesting an elevated trophic position. However, large amounts of isotopic variation were found within all diet components, with only V. thapsus exhibiting a distinct signature. In cage trials, the average δ15N and δ13C of the omnivore declined over time, coinciding with declines in total available prey, though it may be confounded by changes in temperature. The range of δ13C, but not the range of δ15N, also declined over time. This suggests a change in the plant source within the diet, but also some unquantified variability within the population. We suggest that diet variability exists within D. hesperus populations, declining as prey become less abundant.

Southern green stink bug (Nezara viridula, Hemiptera: Pentatomidae) is a pest of macadamia nuts, causing pitting to kernels by feeding. In spite of its pest status, many aspects of the ecology of this insect in macadamia orchards are poorly understood. This study analyzes long-term N. viridula damage to macadamia nuts and investigates the extent to which damage to nuts occurs in the tree canopy, prior to nut-drop. We show that there are distinct seasonal peaks in damage detected after harvest and that, over six years of data collection, mean damage levels were fairly low, albeit with spikes in damage levels recorded. Sampling nuts at peak harvest periods from different strata in the trees and from the ground showed that incidence of damaged nuts within the canopy was typically half as high as on the fallen nuts. Damage to fallen nuts may have occurred prior to nut-drop, and continued to accumulate after nut-drop. These results show that management of N. viridula within macadamia canopies, as opposed to only on fallen nuts, is important. A sampling procedure and predictive model for estimating late-season damage based on early-season damage samples is provided. The model uses January and March damage measurements (based on samples with set level of accuracy), mean temperature and month of the year for which damage is predicted. Early-season damage of 6–10% predicts late-season damage levels that should justify N. viridula suppression based on the nominal threshold (13% damage) used by kernel processors to reject nuts based on damage.

Because immune defenses are often costly employed, insect immunocompetence cannot be always maintained at its maximum level. Here, the oriental fruit fly, Bactrocera dorsalis (Hendel), was used as a study object to investigate how its immune defenses varied with the developmental stage change and mating access. Our data indicated that both phenoloxidase (PO) activity and antibacterial activity significantly increased from new larvae to pupae but decreased in adults after emergence. Furthermore, both the PO activity and antibacterial activity in the hemolymph of copulated male and female adults were dramatically higher than that of virgin male and female ones, respectively. It provided the evidence that copulation could increase the magnitude of immune defense in hemolymph of B. dorsalis. Together, these results suggest that B. dorsalis possess a flexible investment strategy in immunity to meet its specific needs based on the endo- and exogenous factors, such as their distinct food source and living environments.

The seasonal abundance and reproductive output of two common, but little studied, dung-breeding flies, Neomyia cornicina and N. viridescens, were examined in artificial cow pats in pastures in southwest England in 2001 and 2004. In 2001, the numbers of both Neomyia species increased slowly over summer to show a sharp seasonal peak in late August and early September. There was no significant effect of mean temperature, mean relative humidity or dung water content on abundance or seasonally de-trended abundance. High levels of aggregation were seen between pats and, when present, greater numbers of N. cornicina emerged than N. viridescens. Neomyia cornicina was present in 13% of 240 artificial standardized pats put out in 2001, at a median of 19 adults per colonized pat; N. viridescens was present in 8% of artificial pats at a median of three adults per colonized pat. In 2004, N. cornicina emerged from 46% of the 94 artificial pats put out at a median of three adults per colonized pat, while N. viridescens emerged from only 12% of pats at a median of one adult per colonized pat. Flies were also collected in 2004, using sticky-traps and hand nets. Again, free-flying N. cornicina appeared to be more abundant in the field than N. viridescens; 162 N. cornicina were caught compared to 44 N. viridescens over the same sampling period. The size of each adult female was recorded and ovarian dissection was used to determine the numbers of eggs matured. Female N. viridescens were significantly larger than the N. cornicina and matured significantly higher numbers of eggs. Gravid N. viridescens matured a mean of 37.1 (±16.9) eggs, whereas gravid N. cornicina matured a mean of 28.8 (±13.2) eggs. The reasons why the larger, more fecund, N. viridescens adults are less abundant in the field or emerging from pats than N. cornicina are unknown. Further work is required to identify the nature and cause of the mortality experienced by the larvae of these species and the ecological differences and functional specialisation which allows co-existence to be maintained.

The material under consideration was collected by Mr. G. F. Hill, Government Entomologist, at, or in the neighbourhood of, Port Darwin, in the Northern Territory of Australia. It consists principally of cosmopolitan species, two only being peculiar to the country.