The type form of Aëdes (Stegomyia) aegypti (L.) is widespread in southwestern Nigeria, breeding in the basins of rotting tree stumps in the coastal mangrove swamp, in holes in living trees in the freshwater swamp zone and near Lagos and in domestic containers restricted to village clearings in the inland forest zone. Pot surveys were carried out in a rain forest village 50 miles north-west of Lagos and in the capital itself. Baked clay pots holding half a gallon of water were used in each case and were placed in three situations, inside houses, outside but in otherwise sheltered positions, and in fully exposed positions. The degree of larval infestation in both cases was greatest inside houses, but the behaviour pattern was less domestic in Lagos. Larvae were found in pots contaminated with decaying vegetable matter in Lagos but not in the village. Spraying tests indicated that houses and foliage afforded varying degrees of protection to the immature stages of the mosquito. Control of this species is made difficult by the localisation of the immature stages in relatively inaccessible sites and it is suggested that individual treatment of larval habitats by insecticidal pellets before the commencement of the rainy season would ensure a high mortality of first-generation larvae. The toxicity hazard to man is not considered to be great. The development of resistant and wild populations is discussed.

Geometrid moths occurring in late autumn and early spring in temperate forest habitats are often harmful defoliators of deciduous stands. Their populations can cause locally cyclic outbreaks and thus preventive monitoring actions have been developed, mainly based on pheromone attraction of males. Females are mostly flightless with reduced or lost wings and reduced senses associated with flying. Males are standard flyers with well-developed eyes and must be able to deal with rapidly changing light conditions during their activity. Although such differences indicate sex-biased differences in reactions to light, this has been insufficiently tested. In conditions of an experimental arena and using light-emitting diodes, we tested the different reactions of the sexes for nine species to precisely defined short segments of the electromagnetic spectrum in the range 360–660 nm. Across all species, males preferred shorter wavelengths up to 500 nm, while females were nonselective and generally less active. The sexes differed by eye size and body mass, with males having significantly larger eyes and lower body mass. Between brachypterous and apterous females, the former had larger eye size, while body mass differences were statistically insignificant. There were differences between the sexes in move-to-light reactions and changes in eye size and body mass in line with wing reduction. While males preferred a relatively distinct range of shorter wavelengths, a method of attraction to lights with distinct narrow spectra could be used markedly to enhance the established methods of forest pest monitoring, either alone or in combination with chemical male attraction.

There are six strains of the complete genomic sequences of black queen cell virus (BQCV) published in the GenBank, including South Africa (AF183905), South Korea (JX149531), Hungary 10 (EF517515), Poland 4 (EF517519), Poland 5 (EF517520) and Poland 6 (EF517521). Based on the six BQCV strains published in the GenBank, ten pairs of primers were designed in the present study using reverse transcription polymerase chain reaction to obtain the first complete genome sequence of a BQCV strain in China, called the BQCV China-JL1 strain (KP119603). A phylogenetic tree was then built to analyse their genetic relationships. The BQCV China-JL1 strain showed 86–93% similarity with the six strains published in the GenBank. The BQCV China-JL1 strain consisted of 8358 nucleotides (nt). The 5′-proximal open reading frame (ORF1) initiated at nt position 546 and terminated at nt position 4676, ORF3 initiated at nt position 4891 and terminated at nt position 5433, and the 3′-proximal ORF (ORF2) was located between nt positions 5750 and 8203.

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.

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 raspberry cane midge Resseliella theobaldi (Barnes) is one of the most important pests of cultivated red raspberry Rubus idaeus L. throughout Europe. For the last 50 years several studies have been made on the biology, life cycle and control of the pest. Some data can also be found on its natural enemies, but among these species only the chalcidoid Tetrastichus inunctus Nees turned out to be important in controlling raspberry cane midge populations. However, this species name is now ambiguous as the type is lost. In the present study, Aprostocetus epicharmus Walker was the chalcidoid species that parasitized the larvae of the raspberry cane midge, and its biology seems to be very similar to that of T. inunctus. It is therefore probable that the eulophid species earlier referred to as T. inunctus in the literature is A. epicharmus. Besides discussing this problem, particular consideration and detailed data are given on the biology and life cycle of A. epicharmus in relation to R. theobaldi. Different factors having effect on the population dynamics of both species are also discussed as results of a survey on several red raspberry cultivars, carried out in Hungary between 2002 and 2005.

Culex (Culex) pipiens s.l. (Diptera: Culicidae) comprises two distinct biotypes, pipiens (‘rural’) and molestus (‘urban’), both of which are thought to have differing capacities due to different host preferences. To better understand West Nile encephalitis epidemiology and improve risk assessment, local distinction between these forms is essential. This study assesses phenotypic variation at larval and adult stages of ‘urban’ and ‘rural’ biotypes of the species by complementary use of meristic, univariate and multivariate traits analyzed by traditional and geometric morphometrics. Third- and fourth-instar larvae from a broad area of the city of Novi Sad (Serbia) were collected and reared in the laboratory. After adult eclosion, the sex of each larva was recorded based on the sex of the corresponding adult. Examination of the association between variations of larval traits revealed contrasting variations regarding pecten spines vs. siphonal size and siphonal shape in the ‘rural’ biotype. Siphons of larvae collected in marshes and forest ecosystems outside urban areas were found to be the largest, but possessed the smallest number of pecten spines. In addition, statistically significant female-biased sexual dimorphism was observed in siphonal size, wing size and wing shape. Finally, we propose that an integrative approach is essential in delimitation of Cx. pipiens s.l. biotypes, since their differentiation was not possible based solely on larval and adult traits. Our findings shed light on the phenotypic plasticity important for population persistence in the changing environment of these medically important taxa.

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.

Triatomine bugs carry the parasitic protozoa Trypanosoma cruzi, the causal agent of Chagas disease. It is known that both the parasite and entomopathogenic fungi can decrease bug survival, but the combined effect of both pathogens is not known, which is relevant for biological control purposes. Herein, the survival of the triatomine Meccus pallidipennis (Stal, 1872) was compared when it was coinfected with the fungus Metarhizium anisopliae (Metschnikoff) and T. cruzi, and when both pathogens acted separately. The immune response of the insect was also studied, using phenoloxidase activity in the bug gut and hemolymph, to understand our survival results. Contrary to expectations, triatomine survival was higher in multiple than in single challenges, even though the immune response was lower in cases of multiple infection. We postulate that T. cruzi exerts a protective effect and/or that the insect reduced the resources allocated to defend itself against both pathogens. Based on the present results, the use of M. anisopliae as a control agent should be re-considered.

Oviposition was investigated in five strains of Aedes aegypti (L.), two being DDT-resistant (from Trinidad (STR) and Haiti) and three susceptible (two from West Africa and one (AS) from U.S.A.). Strains were compared with respect to their oviposition at sites illuminated at two levels (0·02 and 6·5 lumens per sq. ft.), each site being composed of a strip of moist white paper and an approximately equal area of open water set against a dark background.

Oviposition on the water surface was consistently less at the lower level of illumination. Generally the moist white paper was preferred by all strains, but oviposition on the water surface was practised more readily by strain AS than by the others, and differences between certain strains (including AS and STR) were significant.

Mass crosses and back-crosses were performed between strains AS and STR. The results were in close agreement with the hypothesis that laying on open-water surfaces is controlled by a genetic system in which there is no dominance.

The frequency of oviposition on an open-water surface was not correlated with two other characteristics (oviposition time and oviposition light preference) that have been investigated in these five strains, nor with DDT resistance.

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.

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.

Ovipositing females of Nupserha bicolor Thoms, ssp. postbrunnea Breun. cause loss of stem length in jute, Corchorus olitorius, by girdling the stem above and below a slit in which the egg is laid. The slit is made by two successive indentations of the mandibles. It is composed of a central pit and two lateral punctures. Girdling is restricted to that portion of the stem which falls within the stem-diameter range of 0·2 cm. to 0·4 cm.

A relationship exists between the length of the mandibles of the female, the depth of the stem tissue from the epidermis down to the periphery of the pith (extra-medullary tissue), and girdling and oviposition.

For girdling, the optimum ratio between the mandibular length and the depth of extra-medullary tissue as measured from the epidermal furrow and ridge of the stem (pentagonal in this region) is 1:0·80 and 1:0·99, respectively. Frequency of girdling gradually decreases in those regions of stem where the depth of extra-medullary tissue increases or decreases these ratios.

All the specimens referred to below were collected by Mr. A. F. Posnette in Trinidad, British West Indies, during December 1943 or in January 1944, and were sent by him to the Imperial Institute of Entomology, London, for identification, because some of them, he thought, were of importance in the pollination of cacao flowers. The majority (46) had been found actually in cacao flowers, and all but one of these were referable to the two species, Forcipomyia quasi-ingrami, Macfie (38) and Lasiohelea nana, Macfie (7). It was these two species which Mr. Posnette believed to be “of great economic importance in Trinidad as pollinators of cacao.” The single exceptional specimen, which did not belong to either of these two species, was probably a small example of Lasiohelea stylifer, Lutz. With these insects were sent a few (8) other specimens from moss on the trunk of a cacao tree. They were, however, quite different species, namely, an Atrichopogon, a Stilobezzia, and a Dasyhelea. The following notes may facilitate the ready recognition and further study of these small insects.

Immature stages of bush fly, Musca vetustissima Walker, were reared at constant temperatures ranging from 18°C to 39°C. Mean egg to adult development times ranged from 7.0 to 25.8 days. Eggs, larval instars I, II and III, and pupae averaged, respectively, 3.1, 4.4, 5.5, 36.4 and 50.6% of the total development time. Mean development rate was a non-linear function of temperature. A non-linear development rate model accurately estimated mean development times of immature stages under both constant and fluctuating temperature regimes. Simulation of dung pad temperatures, from air temperature and solar radiation records, predicted development times of soil- and dunginhabiting stages of M. vetustissima to within 4% of those observed under field conditions.

The identity of Empoasca dolichi Paoli, a serious pest of beans and other crops in Africa, was confused. While processing a collection of leafhoppers from Malawi, E. dolichi was found mixed with other species. The identity of E. dolichi was established with reference to its type material, and two new species and a new subspecies of Empoasca from Malawi and two new species from Nigeria are described. New characters that might help specific identification and show the relationships of groups of species are also illustrated and described.

Doses of 40, 80, 120, and 160 Gy were applied to 5-, 6-, 7-, and 8-day-old Anastrepha obliqua larvae, which were exposed to the Neotropical-native braconids Doryctobracon crawfordi and Utetes anastrephae and the Asian braconid Diachasmimorpha longicaudata. These tests were performed to know the effect of the increase in host radiation on the emergence of the aforementioned parasitoids and the related consequences of oviposition on the host. The study was based on the fact that higher radiation doses may cause a decrease in the host immune activity. There was a direct relationship between the increase in radiation dose and the parasitoid emergence. Both, the weight and the mortality of the host larvae were not affected by radiation. Although the larval weight of the larvae was lower and the mortality was higher in the younger larvae. Both, the number of scars and immature stages per host puparium originated from the younger larvae were lower than those from older larvae. Only U. anastrephae superparasitized more at lower radiation. Superparasitism by D. longicaudata was more frequent at 160 Gy. Qualitative measurements of melanin in the larvae parasitized showed that the levels were lower with increasing radiation. As radiation doses increased, the antagonistic response of the A. obliqua larva was reduced. Host larvae aged 5- and 6-day-old irradiated at 120–160 Gy significantly improve parasitoid emergence. This evidence is relevant for the mass production of the three tested parasitoid species.

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.

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.