An interspersed refuge of susceptible plants in a resistant, spring-sown wheat crop was tested as a strategy to protect crop resistance against evolution of virulence by the wheat midge Sitodiplosis mosellana (Géhin), and also to conserve a biocontrol agent Macroglenes penetrans(Kirby). Eight replicated field experiments were conducted using seed mixtures of 0, 5, 10, 15 and 100% or 0, 5 and 100% susceptible wheat with an agronomically similar wheat expressing the antibiotic resistance gene Sm1. The frequencies of eggs, mature larvae and parasitized larvae in susceptible and resistant wheat spikes, and midge-affected seeds in the harvest, were recorded for each plot. In susceptible wheat, insect densities and seed damage were typical of those in commercial wheat. In resistant wheat, few larvae completed development, 2% or less compared with about 80% in susceptible wheat, when larvae were sampled at maturity. This resistant wheat also deterred midge oviposition, reducing egg densities by 65% compared with susceptible wheat. The wheat midge and its parasitoid oviposited throughout the plots, and parasitism was density independent. The densities of mature midge larvae and parasitoids were in proportion to the size of the refuge. A 5% susceptible refuge produced about 41 mature larvae for each mature larva from the resistant wheat, and provided effective control of damage. An interspersed refuge of susceptible plants in resistant wheat is a promising strategy for sustaining resistance conferred by Sm1 and biocontrol of the wheat midge.

Glossina morsitans and G. swynnertoni were allowed to emerge for three days from pupae placed in each other's habitats and in that of G. pallidipes.

The morsitans in the habitat of swynnertoni were in poorer condition, and survived less well, than in the previous year. This may have been because the release was done a little later in the season, or because the freshly emerged flies were not up to the nutritional standards of a year or two before.

They were, however, nearly as heavy, in later life, as wild morsitans in their own home, and this is contrary to previous experience.

In relation to initial weight, swynnertoni, whether in their own home or as aliens in the habitats of other species, were heavier than morsitans, and in fat and water the alien swynnertoni were heavier than the native ones. However, the difference between the two species may possibly be caused by the fact that swynnertoni, after taking its first meal, cannot apparently fall much below its initial weight at emergence, as morsitans and particularly pallidipes are able to do, so that very hungry morsitans may be represented by swynnertoni which have been cut off by death, and are not available to the catchers.

The males of morsitans and swynnertoni are relatively inactive in early life, which has an important bearing on estimates of population and mean life made from marked flies. The females on the contrary are relatively inactive in later life.

Generally the relation between wing-fray and age found in the previous year is confirmed, except one aberrant result when swynnertoni was released in the habitat of morsitans. Scanty data suggest that the rate of wing-fray during the rainy season is not very different. As before, the females, especially in later life, fray their wings more slowly than the males.

Teneral (unfed) flies below the average size are comparatively non-viable, and about 10 per cent, are too small to survive to obtain their first meal. There is no suggestion that the same applies to non-tenerals.

The external morphology of early larvae is described; the first instar is provided with an egg-tooth in the mouth, which makes it incapable of feeding. Both the first and the second instars are spiny.

Although copulation between morsitans and swynnertoni is random, insemination from interspecific matings often fails, and the sterile egg is aborted. In such cases the left ovary ovulates before the normal time.

The flies and pupae live at about the temperature of the standard climate as recorded in a Stevenson screen ; possibly the flies are a little cooler and the pupae a little hotter.

Granivory can play a pivotal role in influencing regeneration, colonization as well as abundance and distribution of plants. Due to their high abundance, nutrient content and longevity, seeds are an important food source for many animals. Among insects, carabid beetles consume substantial numbers of seeds and are thought to be responsible for a significant amount of seed loss. However, the processes that govern which seeds are eaten and are therefore prevented from entering the seedbank are poorly understood. Here, we assess if DNA-based diet analysis allows tracking the consumption of seeds by carabids. Adult individuals of Harpalus rufipes were fed with seeds of Taraxacum officinale and Lolium perenne allowing them to digest for up to 3 days. Regurgitates were tested for the DNA of ingested seeds at eight different time points post-feeding using general and species-specific plant primers. The detection of seed DNA decreased with digestion time for both seed species, albeit in a species-specific manner. Significant differences in overall DNA detection rates were found with the general plant primers but not with the species-specific primers. This can have implications for the interpretation of trophic data derived from next-generation sequencing, which is based on the application of general primers. Our findings demonstrate that seed predation by carabids can be tracked, molecularly, on a species-specific level, providing a new way to unravel the mechanisms underlying in-field diet choice in granivores.

The biology of Aedes geniculatus (O1.) was studied in 1967–73 in Monks Wood National Nature Reserve, an oak-ash woodland, in southern England. Adult emergence from tree-holes occurred from May to September, and the sex ratio was approximately 1:1. Catches on man indicated that the maximum biting densities occurred in July and August and that females spend about two minutes obtaining a blood-meal. Significant positive correlations were found between their unfed weight and the weight of the blood-meal and also between female wing length and fecundity. The mean number of eggs per batch was 70. Studies with bamboo pots used as artificial oviposition sites in the field showed that the seasonal peak in oviposition spanned July and August, daily ovipositional activity was greatest in mid-afternoon and evening and ovipositing females preferred oviposition sites positioned within 4 m of the ground. A small proportion of eggs hatched during the summer in which they were laid, but most hatched in the following spring. Continuous or intermittent soaking failed to induce hatching until this time. In 'the laboratory, partially em'bryonated eggs required a minimum relative humidity of 88% to develop fully, but some embryonated eggs survived at 58%. Some eggs survived for 18–24 months in the field. The sampling of preadult stages dn tree-holes showed that larvae in the first two instars occurred almost throughout the year while third- and fourth-instar larvae were present in spring and summer. Pupae occurred only in the summer. It was concluded that A. geniculatus is univoltine in Monks Wood.

Geographic body size variation was analysed in males and females of 19 populations of the South American grasshopper Dichroplus vittatus Bruner spanning 20 degrees of latitude and 2700 m of altitude. Using mean and maximum body length of each sex and factors obtained from principal components analyses of six morphometric linear characters it was shown that D. vittatus followed the converse to Bergmann's rule latitudinally but not altitudinally where no significant trends were observed. For males, variability of body size increased with latitude but not with altitude. Both types of trends were significantly correlated with mean annual temperature and minimum annual temperature (positive correlations), and two estimators of seasonality, the coefficients of variation of mean annual temperature (negative) and mean annual precipitation (positive). Some allometric relationships also showed geographic variation. It is suggested that the observed decrease in size with latitude together with the increase in morphological variability is a consequence of a number of factors: the shortening of the growing season southwards; the increasing seasonality and climatic unpredictability; and the fact that the species exhibits protandry which contributes to smaller and more variable size in males and smaller but more constant body size in females.

The responses of male and female Lutzomyia longipalpis (Lutz & Neiva) to different wavelengths of light was tested by presenting the sandflies with two light sources simultaneously, a series of test wavelengths between 350–670 nm and a 400 nm control. To test whether L. longipalpis could discriminate between the test and control, three sets of experiments were carried out in which the test wavelengths were presented at higher, equivalent or lower intensity than the control. In all three experiments, ultra-violet (350 nm) and blue-green-yellow (490–546 nm) light was more attractive to L. longipalpis than the control wavelength. However, at low intensity, UV was less attractive, than equivalent or higher intensity UV light. At intensities equivalent to or higher than the control wavelength, ultra-violet light was more attractive than blue-green. Furthermore, at low intensity, green-yellow (546 nm) light was more attractive to males whereas blue-green (490 nm) was more attractive to females. Blue-violet (400 nm) and orange-red (600–670 nm) light were least attractive in all three sets of experiments. Response function experiments indicated that the responses were dependent on both intensity and wavelength and that therefore more than one photoreceptor must be involved in the response. The results indicated that L. longipalpis can discriminate between different wavelengths at different intensities and thus have true colour vision. It also suggests that L. longipalpis may be able to navigate at dusk or under moonlight or starlight conditions using light in the blue-green-yellow part of the spectrum. The difference in response of males and females to light in this region is interesting and may indicate the different ecology of the sexes at night. Overall, these results may have important implications for sandfly trap design.

The Eriophyid gall mite, Aceria chondrillae (G. Can.), which is distributed from south-east Russia to Portugal, was studied in the Mediterranean region as part of a biological control programme against skeleton weed (Chondrilla juncea) for Australia. The mite induces the vegetative and flower buds of Chondrilla to form leafy galls in which the full life-cycle is completed, causing stunting of the plant and reducing seeding. The mite overwinters in the rosettes of C. juncea without inducing gall development or reproducing. Populations decrease markedly during winter, recover in spring and infestations spread rapidly during summer. Reproduction is sexual and spermatophores are deposited by the males. Amblyseius sp. preys on A. chondrillae without marked effect. Tests made by placing fully developed galls of A. chondrillae on 75 species of plant including certain Cichoriaceae closely related to Chondrilla showed that the mite was highly specific to Chondrilla. Comparative tests with four geographical strains of A. chondrillae against six forms of C. juncea of various geographical origins indicated that the strains were specialised to their usual host form of the plant. A Greek strain of the mite readily attacked the main Australian form of C. juncea, and this strain has been introduced into Australia as a biological control agent for the weed.

In this study, silkworm moth (Bombyx mori L.) larvae were regarded as an animal protein source for astronauts in the bioregenerative life support system during long-term deep space exploration in the future. They were fed with mulberry and stem lettuce leaves during the first three instars and the last two instars, respectively. In addition, this kind of environmental approach, which utilised inedible biomass of plants to produce animal protein of high quality, can likewise be applied terrestrially to provide food for people living in extreme environments and/or impoverished agro-ecosystems, such as in polar regions, isolated military bases, ships, submarines, etc.

Respiration characteristics of the larvae during development under two main physiological conditions, namely eating and not-eating of leaves, were studied. Nutrient compositions of silkworm powder (SP), ground and freeze-dried silkworms on the 3rd day of the 5th instar larvae, including protein, fat, vitamins, minerals and fatty acids, were measured using international standard methods.

Silkworms’ respiration rates, measured when larvae were eating mulberry leaves, were higher than those of similar larvae that hadn't eaten such leaves. There was a significant difference between silkworms fed on mulberry leaves and those fed on stem lettuce in the 4th and 5th instars (P<0.01). Amounts of CO2 exhaled by the silkworms under the two physiological regimes differed from each other (P<0.01). There was also a significant difference between the amount of O2 inhaled when the insects were under the two physiological statuses (P<0.01). Moreover, silkworms’ respiration quotient under the eating regime was larger than when under the not-eating regime. The SP was found to be rich in protein and amino acids in total; 12 essential vitamins, nine minerals and twelve fatty acids were detected. Moreover, 359 kcal could be generated per 100 gram of SP (dry weight).

The dispersion of Scaphoideus titanus Ball adults from wild to cultivated grapevines was studied using a novel mark–capture technique. The crowns of wild grapevines located at a distance from vineyards ranging from 5 to 330 m were sprayed with a water solution of either cow milk (marker: casein) or chicken egg whites (marker: albumin) and insects captured in yellow sticky traps placed on the canopy of grapes were analyzed via an indirect ELISA for markers’ identification. Data were subject to exponential regression as a function of distance from wild grapevine, and to spatial interpolation (Inverse Distance Weighted and Kernel interpolation with barriers) using ArcGIS Desktop 10.1 software. The influence of rainfall and time elapsed after marking on markers’ effectiveness, and the different dispersion of males and females were studied with regression analyses. Of a total of 5417 insects analyzed, 43% were positive to egg; whereas 18% of 536 tested resulted marked with milk. No influence of rainfall or time elapsed was observed for egg, whereas milk was affected by time. Males and females showed no difference in dispersal. Marked adults decreased exponentially along with distance from wild grapevine and up to 80% of them were captured within 30 m. However, there was evidence of long-range dispersal up to 330 m. The interpolation maps showed a clear clustering of marked S. titanus close to the treated wild grapevine, and the pathways to the vineyards did not always seem to go along straight lines but mainly along ecological corridors. S. titanus adults are therefore capable of dispersing from wild to cultivated grapevine, and this may affect pest management strategies.

The long range orientation of West African mosquitoes to birds was studied using ramp-traps set up 3–23 m from the bait. The baits comprised chickens, ducks, pigeons and the carbon dioxide equivalent of the chickens. From the pattern of convergence of mosquitoes to the baits, it was shown that Anopheles melas Theo. and Culex thalassius Theo. were orienting to all the bird-baits from distances of at least seven metres. Responses to carbon dioxide were only apparent at a distance of three metres indicating the greater range of effect of the chickens over their carbon dioxide equivalent. Mosquitoes of the largely bird-biting C. decens group showed no long range response to any bait, even though they were entering pigeon-baited traps and to a limited extent feeding on the birds. Catches of A. melas in bird-baited traps were larger at the foot of a tall tree than in the foliage at 5·33 m; for Culex spp. the converse was true. Catches of Culex at 5·33 m outside the tree were smaller than within the foliage.

Three different patterns of feeding of sixth-instar spruce budworm, Choristoneura fumiferana Clemens were simulated in the laboratory. Larvae were fed artificial diets whose nitrogen and total soluble sugar contents varied according to levels similar to those found in three types of balsam fir, Abies balsamea (L.) Miller foliage (current-year foliage from middle and lower crown sections and one-year-old foliage). The biological performance of offspring was studied according to the nutrition of their parents. Although food quality had no impact on pupal weight of female parents and individual mean egg weight, progeny fitness was influenced by parental nutrition. Old foliage simulated diet, poor in nitrogen, clearly affected the early larval development of progeny, especially the percent of egg hatch and first-instar survival. Lower crown current-year foliage simulated diet, with low total soluble sugar content, reduced the first-instar survival of the progeny. However, the selective pressure exerted by low food qualities on the parental generation and on the early stages of their progenies resulted in C. fumiferana populations having higher tolerance to starvation and higher survival after the diapause period. These results highlighted the potentially direct and indirect effects of C. fumiferana parental nutrition on the next generation. The patterns of feeding of parental generations would appear to affect the quality and size of subsequent populations through several selections on the different life-history stages of both generations.

We studied the use of a supervised artificial neural network (ANN) model for semi-automated identification of 18 common European species of Thysanoptera from four genera: Aeolothrips Haliday (Aeolothripidae), Chirothrips Haliday, Dendrothrips Uzel, and Limothrips Haliday (all Thripidae). As input data, we entered 17 continuous morphometric and two qualitative two-state characters measured or determined on different parts of the thrips body (head, pronotum, forewing and ovipositor) and the sex. Our experimental data set included 498 thrips specimens. A relatively simple ANN architecture (multilayer perceptrons with a single hidden layer) enabled a 97% correct simultaneous identification of both males and females of all the 18 species in an independent test. This high reliability of classification is promising for a wider application of ANN in the practice of Thysanoptera identification.

Very few studies have examined, at the field scale, the potential for faecal residues in the dung of avermectin-treated cattle to affect dung-breeding insects. The current study examined populations of dung beetles (Scarabaeidae: Aphodius) using pitfall traps baited with dung from untreated cattle on 26 fields across eight farms in southwest Scotland. The fields were grazed either by untreated cattle or by cattle treated with an avermectin product, i.e. doramectin or ivermectin. During the two-year study, significantly more beetles were trapped in fields grazed by treated cattle (n=9377 beetles) than in fields where cattle remained untreated (n=2483 beetles). Additional trials showed that beetles preferentially colonised dung of untreated versus doramectin-treated cattle. This may explain the higher captures of beetles in traps baited with dung of untreated cattle, which were located in fields of treated cattle. Given that Aphodius beetles avoided dung of treated cattle in the current study, the potential harmful effects of avermectin residues in cattle dung could be reduced through livestock management practices that maximise the availability of dung from untreated livestock in areas where avermectins are being used.

An actograph apparatus is described for recording in 24-hour periods, under controlled conditions, the activity of Locusta migratoria migratorioides (R. & F.) in terms of distance travelled.

Great variation was observed in the amount of activity shown by different individuals and the activity of any one individual is shown to vary considerably over each stadium, the highest level occurring about half-way between moults, and falling off towards the beginning and end of each stadium.

An insect is shown to be capable of very intense activity immediately before a moult if no convenient moulting place is found.

No significant difference is found between the activity of males and females, but the average distance travelled in a 24-hour period in the 4th and 5th stadia is shown to be greater than that in the 2nd or 3rd.

The daily activity of adults is shown to vary considerably from day to day, and the diurnal distribution of the activity of adults up to seven days old is shown to be similar to that of nymphs.

The unequal distribution of activity over each 24-hour period is shown to be due to absence of fresh food in the second half of each record, and the effect of this starvation is shown to vary according to the stage of development of the insect.

The effects of changes in relative humidity on the amount and distribution of activity are shown to be very slight or none.

A diurnal periodicity is shown to be induced in the insects when reared under alternating 12-hour periods of light and dark. The longer the conditioning lasts, the more clear-cut is the periodicity. In constant darkness the periodicity is retained for only a few days and gradually disappears.

A tendency for periods of high activity to recur every 2–2½ hours is demonstrated in certain records. In the other records, constituting actually the majority, it is suggested that the periodicity is masked or that the locust's nervous mechanism is inadequate to maintain it.

Preliminary experiments with a form of trophograph suggest that the 2–2½ hour periodicity may be associated with a hunger rhythm.

The comparative influence of Busseola fusca (Fuller) and Chilo partellus (Swinhoe), both as separate and mixed populations, on growth and yield of grain sorghum was investigated in a field experiment, using an artificial infestation in cages. C. partellus was more injurious than B. fusca as indicated by whorl damage, stalk injury and yield loss. In the case of mixed populations, dispersion of larvae and damage were independent of B. fusca numbers. A regression equation, Logit Y = 0.24 + 2.06 logit x, relating visible plant damage to yield loss was determined. Control strategies in the case of mixed stem borer populations should be directed against C. partellus.

Hourly and nightly catches of Heliothis armiger (Hb.) and H. punctiger Wllgr. at a site adjacent to 2000 ha of commercial cotton in the Namoi Valley of New South Wales, were analysed in relation to various environmental factors and showed that wind speed, temperature, night-length and (H. armiger only) moonlight exerted a significant influence on trap-catch. For H. punctiger and H. armiger respectively, these factors accounted for 80 and 60% of the deviance in hourly catches but only 70 and 40% of the variation in nightly catches. Wind speeds of more than 1·7 m/s suppressed the catch of both species but had a greater effect on H. punctiger than H. armiger. Whereas with both species, the optimum temperature for trapping was about 27°C, temperature had a greater influence on the catch of H. punctiger than of H. armiger. Bright moonlight was estimated to reduce the catch of H. armiger by 49%, but no significant effect was detected for H. punctiger. The analysis revealed a number of occasions for both species in which the hourly distribution of catch and/or the change in catch between successive nights was aberrant. With H. armiger, these inconsistencies appeared to be associated with changes in population due to adult emergence, whereas for H. punctiger the most likely cause seemed to be changes due to movement. The combined effects of wind speed, temperature, night-length and moonlight were used to adjust the nightly catches of each species according to the environmental conditions prevailing on a ‘ standard’ night. This was defined as a typical summer's night with temperatures decreasing from 28·8°C at dusk to 20·6°C at dawn and ideal catching conditions, i.e. no moon and wind speed never exceeding 1·7 m/s. As such, the adjusted catches could be taken as indices of moth abundance. These showed that H. armiger had three discrete periods of abundance, characterised by the presence of large numbers of young moths and spaced at intervals suggesting successive generations. A similar pattern was lacking in H. punctiger, which was abundant only during the first half of the season. Except during periods of emergence (H.armiger), or once when spraying occured during daylight, the aerial application of insecticides to the cotton adjecent to the light-trap resulted in marked reductions in the populations of both species.

The guava fruit fly, Bactrocera correcta (Bezzi) (Diptera: Tephritidae), is an invasive pest of fruit and vegetable crops that primarily inhabits Southeast Asia and which has the potential to become a major threat within both the Oriental and Australian oceanic regions as well as California and Florida. In light of the threat posed, it is important to develop a rapid, accurate and reliable method to identify B. correcta in quarantine work in order to provide an early warning to prevent its widespread invasion. In the present study, we describe a species-specific polymerase chain reaction assay for the diagnosis of B. correcta using mitochondrial DNA cytochrome oxidase I (mtDNA COI) barcoding genes. A B. correcta-specific primer pair was designed according to variations in the mtDNA COI barcode sequences among 14 fruit fly species. The specificity and sensitivity of the B. correcta-specific primer pair was tested based on the presence or absence of a band in the gel profile. A pair of species-specific B. correcta primers was successfully designed and named BCOR-F/BCOR-R. An ∼280 bp fragment was amplified from specimens belonging to 17 geographical populations and four life stages of B. correcta, while no such diagnostic bands were present in any of the 14 other related fruit fly species examined. Sensitivity test results demonstrated that successful amplification can be obtained with as little as 1 ng μl−1 of template DNA. The species-specific PCR analysis was able to successfully diagnose B. correcta, even in immature life stages, and from adult body parts. This method proved to be a robust single-step molecular technique for the diagnosis of B. correcta with respect to potential plant quarantine.

In recent decades, aphids identified as Cinara cupressi (Buckton) have seriously damaged commercial and ornamental plantings and native stands of Cupressus, Juniperus, Widdringtonia and other Cupressaceae in Africa, Italy, Jordan, Yemen, Mauritius and Colombia. Aphids currently identified as Cinara cupressiappear to belong to a species complex. This work was undertaken to identify the pest, its likely area of origin and any specific natural enemies, to facilitate a biological control programme. The biogeography of the species complex was studied using morphometric analysis of specimens from all the major regions where they have been collected, and analysis of host-plant ranges, parasitoid records and host association information. The cause of tree damage is shown to be an unnamed species, here described as C. (Cupressobium) cupressivora Watson & Voegtlin sp. n., which probably originated on Cupressus sempervirens in a region from eastern Greece to just south of the Caspian Sea. The remainder of the complex, Cinara cupressisensu lato, apparently consists of three morphologically similar species (C. sabinae(Gillette & Palmer) and C. cupressi (Buckton), probably originating in North America, and an unidentified species). There is insufficient data available to separate these taxa, or to determine the status of C. canadensis Hottes & Bradley, so C. sabinae and C. canadensis are left in synonymy under C. cupressi (Buckton). Lachniella tujae del Guercio and L. juniperi signata del Guercio, thought to be part of the C. cupressi complex, were found to be junior synonyms of C. tujafilina (del Guercio); these new synonymies are proposed and lectotypes of L. tujae and L. juniperi signataare designated.

During my work on the life-history of the Chalcid, Euchalcidia caryobori, Hanna (Hanna 1933), which parasitises the pupae and the late larval stages of the Bruchid, Caryoborus pallidus, Oliv., infesting senna pods, great difficulty was experienced in obtaining the material. Infested senna pods arrive in London from the Sudan between June and August. Any pods arriving after or before that are not usually infested to any considerable extent. To guard against this lack of material, a large supply of parasitised and unparasitised pupae of the Bruchid was obtained when available by sifting the senna pods and keeping them in large glass jars at a constant temperature of 27°C. The Chalcid soon emerges and deposits its eggs through the cocoon on the unparasitised pupae of the Bruchid and feeds on peeled sultanas placed on a cardboard tray on top of the material and moistened every day. The sultanas were changed every three days to avoid fermentation.

A wind-tunnel bioassay system, developed previously for the evaluation of long-range host-location stimuli, was used to investigate the responses of Anopheles arabiensis Patton to floral odours. Mosquitoes were found to respond by flight and landing to Achillea millefolium inflorescences and also to the odour of A. millefolium in the absence of visual stimuli. An air-entrainment technique was used to extract floral odours for biological and chemical testing. Both sexes of Anopheles arabiensis were found to respond to the floral odour extract. The major component of the floral odour was tentatively identified as a cyclic or bicyclic monoterpene.