Larvae of the pine beauty moth Panolis flammae (Denis & Schiffermüller) were reared in sleeve cages on five different seed origins (provenances) of pole stage Pinus contorta in the field in each of four years from 1985 to 1988. Survival varied significantly between the years. In those years when survival was high, Significant differences between tree provenance were not found. However, between provenance significant differences were found in larval weight and stage of development. In the years when survival was low, the results seen in good years were reversed. significant differences attributable to provenance were found but these were not reflected in significant differences between larval weight or development. In addition, there was a significant correlation between the proportion surviving and larval weight, which was not the case in those years where larval survival was high. The results are discussed in light of the pest status of P. flammea in Britain and in view of current silvicultural policies. The use of trees resistant to insect attack as part of an integrated pest management programme is highlighted and the need to coordinate laboratory and field studies so as to control for environmental variation discussed.

The genitalia and reproductive organs of a normal and of an abnormal type of cabbage root fly (Delia brassicae (Wied.)) are described. The abnormal type, possessing incomplete genitalia, was found in the Welles-bourne laboratory culture. The abnormal females were sexually attractive to males but were unable to copulate or lay eggs, whereas the abnormal males copulated but did not inseminate females. The age of females at oviposition and both larval and adult diets influenced the number of abnormal flies in subsequent generations.

Chelonus chailini sp. n., which was discovered recently during a survey of potential biocontrol agents of the cocoa pest Conopomorpha cramerella (Snellen) in Malaysia, is described and illustrated. Five other gracillariid leaf-miners and bud-borers (Acrocercops globulifera Meyrick, A. diffluella van Deventer, A. caerulea Meyrick, A. phaeospora Meyrick and Epicephala chalybacma Meyrick) are cited as hosts of C. chailini, and brief notes on its biology are given.

The cereal rust mite, Abacarus hystrix, is one of the most notable among mites causing losses in cultivated grasslands. It is one of a few eriophyoid species for which a broad host range has been reported. Recent studies, however, have shown that host specialization is very likely in this species. For two populations of A. hystrix (one inhabiting perennial ryegrass, the second inhabiting quackgrass), host-associated differences correlated with strong host fidelity, distinct phenotypes and reproductive barriers have been found. In the present study, the ability of wheat colonization by quackgrass- and ryegrass-adapted cereal rust mite was studied. The hypothesis that the potential for wheat colonization by the quackgrass strain is more likely was tested by comparing the colonization performance (assessed by female survival and fecundity) of quackgrass- and ryegrass-associated A. hystrix on their familiar hosts and on wheat. The ryegrass population had no success in wheat colonization (expressed by extremely low fecundity and female survival). Fecundity and survival of quackgrass strain were similar on wheat and the familiar host, or even higher on wheat. Phylogenetic similarity of quackgrass and wheat is discussed as a possible factor that might influence such patterns of host colonization. Since A. hystrix is the only vector of the ryegrass mosaic virus (RgMV), the presented results may be helpful in explaining the inability of RgMV to successfully infest wheat. The conclusions are that (i) quackgrass- and ryegrass-adapted strains of the cereal rust mite have different physiological host ranges and (ii) phylogenetic relationships between host plant species appear to be drivers for host specialization in this mite species.

Drosophila suzukii is an invasive fruit pest in Europe and America. Females lay eggs into mature fruit that larvae consume causing important losses. Sterile insect technique (SIT) is under development to control this pest. The efficiency of this technique relies on insect quality. However, during the process from mass production to field release, several steps may compromise insect quality and therefore SIT success. Shipment of sterile insects after irradiation is a key step of SIT programmes. Generally, insects are shipped as pupae and conditions during transport need to be adapted to prevent emergence before field release, while guaranteeing insect quality. To do so, transport is usually performed under low temperature, hypoxia or a combination of both. However, the impact of multiple stressors such as irradiation followed by chilling combined with hypoxia is poorly described and has not been studied in D. suzukii. Therefore, the aim of this study was to simulate a shipment of D. suzukii pupae (irradiated or not) under different conditions (chilling combined or not with hypoxia) for various durations, and to assess consequences on emerged adults. Irradiation followed by hypoxia and/or chilling only weakly altered emergence. However, 48 h of hypoxia without chilling altered the flight ability of flies whether or not they were irradiated. Conversely, when hypoxia was combined with chilling, flight ability remained similar to that of untreated flies. The use of chilling in combination with hypoxia for 48 h could be implemented as a transportation method for SIT programme on D. suzukii.

A method is described by which a continuous supply may be produced, efficiently, of large numbers of adults of Drosophila melanogaster Mg. of known age and sex for microbioassay tests.

Equal numbers of male and female flies were introduced into breeding jars containing a nutrient medium and maintained at 24–25°C. and 60–80 per cent, relative humidity. They were removed ten days later, just before the emergence of their progeny.

It was found that the physical conditions in the culture jars exerted an appreciable influence on several aspects of the breeding of Drosophila. Thus, in trials in which the surface of the nutrient medium was flat and unbroken, with a pad of cotton-wool laid on it to provide suitable sites for pupation, and with or without a layer of cotton-wool beneath it, or in which the medium was broken with irregular lumps, laid on a layer of cotton-wool and arranged with a space, filled with cotton-wool, at the centre, the best results were obtained with the last modification.

Under these conditions, emergence of adults began earlier and reached its peak earlier, a most constant sex-ratio and a higher number of progeny per female, and consequently a higher yield of flies per culture jar, were obtained.

A special device, which takes advantage of the positive phototropism of the flies emerging from a group of culture jars enclosed in a darkened box with an exit funnel leading into a collecting jar, made it possible, by daily replacement of the collecting jar, to remove practically all newly emerged flies within 24 hours, so that the known age of any batch is accurate within the limit of one day.

Male flies have been found to be twice as susceptible as females and give a greater response to differences in dosage of toxicant. For this reason male flies only are to be preferred for use in bioassay experiments.

Using another device, the flies were therefore sexed, and the required number of batches of males collected. This device consists of a glass-covered container through which a gentle continuous stream of CO2/air is passed over the flies, which have already been anaesthetised with CO2. The male flies are taken up individually with a small aspirator and passed direct into test tubes where they are collected in batches.

Difficulty is being experienced in obtaining natural regeneration of Juniperus procera in the Daloh Forest, Erigavo, British Somaliland due to infection of the seed by an unidentified species of Megastigmus. In 1953, Mr. A. R. Tribe succeeded in breeding specimens from infested seed, and this material, together with a subsequent collection by Mr. J. J. Lawrie in January 1954, has been used as the basis of the following description.

A few larve of Tabanus fasciatus niloticus were obtained on 4th March 1925 near Renk, on the White Nile, their habitat being the Nile cabbage (Pistia stratiotes, Linn.). They were by no means common, a search of a couple of hours yielding but seven specimens. They were lying submerged in the water, supported on the bases of the lower leaves in such a position that their caudal respiratory siphons could be extended to reach the surface of the water, and never more than a single larva occurred on an individual plant. In appearance they were typical Tabanid larvae, except as regards colour ; the normal colour is white to yellowish, but the larvae in question were bright green, similar to the green of the leaves among which they were situated. They were placed in a glass jar with water, plant débris and some Nile cabbages, and taken to Khartoum, the journey occupying ten days. When the contents of the jar were examined in Khartoum two larvae were recovered and removed each to a test-tube containing a roll of filter-paper and water. They fed readily on earthworms.

Rice tungo virus is tranmitted by Nephotettix impicticeps Ishihara but not by the closely related N. apicalis (Motsch.). Hybrids have been obtained from crosses between these two species. The morphological characteristics of the hybrids were not identical with either parent in respect to the marking on the abdomen of the nymphs, the submarginal black band on the vertex of the adults, or the number of teeth on the ventral surface of the aedeagus of the male genitalia. However, more than 10 per cent. of them, regardless of stage of development or sex, were able to transmit the tungo virus, indicating that the transmissive ability is inherited even in an interspecific cross. The virus seems to be nonpersistent in the hybrids as it is in N. impicticeps.

Collections recently received by the Imperial Bureau of Entomology, chiefly from Natal, have brought to light several interesting new forms in this group of flies, and their study has yielded certain unlooked for results which it appears desirable to place on record, together with descriptions of the new species, the types of which have been presented by the Bureau to the British Museum. The opportunity has been taken of publishing revised keys to the African species of Banksinetta and Taeniorhynchus.

The examination of samples of Antestiopsis orbitalis (Westw.) from different parts of South Africa has shown complete intergradation between the colour patterns of the typical subspecies and that of the form facetus (Germ.), hitherto of indeterminate infraspecific status, and the latter name is suppressed. Additional localities of ocurrence are given for A. orbitalis, and Antestia rufovittata Dist. is redescribed and transferred to Antestiopsis.

The permeability of the crop surroundings to pests and the landscape structure can influence pest dispersal between crop patches as well as its abundance within the crop. In this work, we analyzed the dispersal of the olive moth Prays oleae (Bernard) throughout the olive grove surroundings and their abundance within the crop following three approaches: (i) pollen grains settled on bodies of olive moths collected in olive groves were identified and compared with flora occurring on the surrounding patches; (ii) the capability of P. oleae males to penetrate non-crop patches was analyzed (iii) the effect of the landscape structure on the abundance of the three generations of the olive moth was studied. Pollen grains of scrubs and other trees occurring in the crop surroundings, such as Cistus sp., Quercus sp., Juniperus-type or Pinaceae were identified on P. oleae bodies suggesting that P. oleae penetrates into non-crop habitats. Additionally, woody and, to a lesser degree, herbaceous patches, did not constitute barriers for P. oleae. Finally, more complex and heterogeneous patches presented lower numbers of captures of P. oleae. These results give new insights into the movements of the olive moth in the olive grove surroundings and suggest that the management of non-crop areas could influence this pest abundance.

Observations were made in Sierra Leone from September 1949 to November 1951 on the incidence of trypanosomes in Glossina palpalis (R.-D.), in continuation of those previously reported that began in September 1948. Flies were dissected; trypanosomes found to be restricted to the proboscis were classed as Trypanosoma vivax and those found also or only in the mid-gut as T. congolense. None of the flies had infected labial glands. The whole data are presented for the sexes separately by months.

The existence of a marked seasonal variation in the incidence of T. vivax in G. palpalis is confirmed. The highest rates of infection occured in the months of heavy rain, and there was a significant inverse correlation between the monthly means of infection rate and of hours of sunshine. The cause is unknown, but possible explanations are discussed.

The older the fly, as judged by its appearance, the greater the rate of infection by both species of trypanosme; the virtual absence of infection in the youngest group of flies does not support the theory that they can only be infected when very young.

In the case of T. vivax, but not in that of T. congolense, females flies were more heavily infected than males. This may be due to larger food intake by the females, or to males, because of their more active life, appearing to be older than they are.

A résumé is given of the recommendations hitherto made for the control of the Narcissus flies, Merodon equestris and Eumerus tuberculatus. Nevertheless, the control of these pests still remains a major problem in the British Isles. Laboratory and field experiments on the control of both these species were carried out in 1946 and 1947. In the field trials, dichloro-diphenyl trichlorethane (DDT), benzene hexachloride (BHC) and mercurous chloride (calomel) were included. The DDT and BHC were applied in the form of sprays, at a concentration of 0·5 per cent. suspension in water, over the aerial parts of the Narcissus plants and the surrounding soil on three separate occasions at approximately monthly intervals during the oviposition period, starting on May 10, some two or three days before the adult flies normally appear in the district. The calomel was applied in the form of a 4 per cent. dust on separate occasions during this period.

BHC and DDT were successful in producing a marked reduction in the degree of infestations by both species of Narcissus flies and, of the two insecticides, the former was apparently more effective. Although calomel dust afforded an appreciable protection against attacks by the Large Narcissus Fly, M. equestris, it exercised negligible control of the Small Narcissus Fly, E. tuberculatus, in these experiments. It seems from the results obtained in the present investigations that DDT and, in particular, BHC do provide a much more effective and practical means of controlling infestations of the Narcissus flies than any other methods hitherto tested.

The goal of this paper is to examine and demonstrate that survival analysis, which has been a de facto standard in biomedical research since the 1990s but has not been widely adopted in entomology yet, should possess similar potential in entomological research. The following three objectives are set to achieve this goal: (i) addressing a fundamental issue – censoring or incomplete observations; (ii) demonstrating the application of survival analysis to analyze insect life tables; and (iii) applying survival analysis for hypothesis testing. The data used to demonstrate the applications is from our laboratory experiments, which recorded the development, survival and reproduction of 1800 Russian wheat aphids (Diuraphis noxia (Mordvilko), RWA) under 25 treatments of temperature and plant-growth stage. With regard to the first two objectives, besides examining the near ubiquitous existence of censoring in insect population research, we constructed and analyzed life tables of 1800 RWA individuals with survival analysis. We further demonstrate that there could be very significant differences in life table parameters, such as median development times with and without considering censoring. To the best of our knowledge, this is the first recognition in entomology that censoring, which is hardly avoidable, can cause significant systematical bias (ranging between 4–25%; table 1) in insect development data analysis. As for the third objective, the study shows that four statistics from survival analysis can be applied to testing the effects of covariates, such as temperature and plant-growth stage, on development and survival of the Russian wheat aphid. The advantages of survival analysis include the handling of censored observations, survival probabilities in the form of rigorous survivor function vs. simple survival rates, dynamic modeling of covariates effects on development and survival with a unified model structure, etc. The methods demonstrated in this article should also be useful for entomological research beyond insect demography, such as bioassay, assessment of natural enemies, the studies of insect behaviors, etc.

The subject which I propose to introduce is one which is of such very great importance in agricultural practice in different parts of the world that I trust it may not be out of place to give a brief account of the experiments in connexion with it, which we have been conducting in Egypt and which, although still incomplete, indicate very favourable results.

For some years prior to 1935, the cotton Capsid of Uganda, which is now known to occur in several other parts of Africa also, was called Lygus vosseleri, Popp. In 1935, Mr. W. E. China of the British Museum (Natural History), after examining type material, published a note synonymising vosseleri of Poppius with simonyi of Reuter and concluded that the cotton Capsid previously identified by him as L. vosseleri, Popp., must therefore be called L. simonyi, Reut. This latter name has been in general use for the cotton Capsid since 1935 and is very widely known because of the great importance of the insect as a pest of cotton.

The persistent toxicity of films of pyrethrum in P31 oil may endure on suitable surfaces under warehouse conditions for much longer periods than hitherto supposed, but unexplained fluctuations in toxicity may occur.

Within the range 0·8 per cent. to 1·3 per cent. total pyrethrins, the pyrethrum content appears to be only a minor factor in determining the persistent toxicity of such films.

The nature of the surface sprayed is of great importance in determining the persistent toxicity of pyrethrum films in P31 oil, which is negligible on concrete and increases steadily through the following list of surfaces—brick, heavy hessian, light hessian, jute, cotton, and wood; the last-mentioned two being particularly good substrates.

Residual deposits of DDT or “ Gammexane ” derived from kerosene sprays are of little use on concrete, but appear otherwise little affected by the nature of the surface treated; they give a uniform degree of persistent toxicity on the various surfaces listed.

The response of populations of the saw-toothed grain beetle, Oryzaephilus surinamensis (Linnaeus) (7022/1 strain), to insecticide treatments of different extent and standard concentration was studied over 16 weeks (no more than two generations) in experimental bins containing a wheat bulk and 16 kibbled wheat-filled refuges. Populations comprised initially low frequencies of resistant phenotypes, as would occur in natural populations where resistant alleles had newly arisen. The degree of control achieved was related to the extent of treatment. Distribution of adult beetles was greatly influenced by the effects of insecticide treatment superimposed on intrinsic microhabitat preferences. Live beetles were recovered from all bins, although numbers sampled from wheat bulks of treated bins were 1–6% of that of the untreated bin. More live beetles were sampled from wheat bulks than were recovered from all respective refuges, except in one treated bin. Live beetles were more numerous in refuges in corners and in those furthest from refuges on treated walls. Beetles were more likely to die in refuges in coiners and lower down in the bins or in refuges on treated walls adjacent to untreated walls. Although treatments produced heavy mortality, the frequencies of resistant individuals did not increase significantly. This could either be because treatments were equally successful in eliminating homozygous susceptible and heterozygous individuals, or because selection in favour of resistant individuals was too weak to be detectable, especially if there were negative correlations between viability and fecundity. Significant genetic structuring of refuge subpopulations with respect to the resistance phenotypes was noted and appeared to be related to behavioural preferences for microhabitat.