bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field observations on competitive displacement, at the preimaginal stage, of Culex quinquefasciatus Say by Culex cinereus Theobald (Diptera: Culicidae) at the Kenya Coast
Authors: Subra R. , Dransfield R. D. 
Published: July 2009

AbstractIn certain areas of the Kenya coast, Culex quinquefasciatus Say is unable to maintain itself in breeding sites (flooded pit latrines) which it has to share with C. cinereus Theo. The pattern of settlement of the two species and the replacement of C. quinquefasciatus by C. cinereus were studied from May to November 1980 by monitoring newly emerged males as they departed from two breeding sites located in a small village near Mombasa. C. quinquefasciatus was the first species to be recorded from both sites, soon after they were flooded by the early rains. C. cinereus came later and did not increase markedly until after the late rains. The pattern of replacement of C. quinquefasciatus by C. cinereus was similar in the two breeding sites; the former species was unable to maintain itself once C. cinereus started to increase. Studies in another village showed that, after displacement, egg laying by C. quinquefasciatus continued but at a much reduced level. It is suggested that this is an example of competition-mediated succession occurring annually, with C. quinquefasciatus being better adapted to exploit rapidly the newly flooded sites but unable to sustain later competition from C. cinereus.
Reservoirs forAphidius erviHaliday (Hymenoptera: Aphidiidae), a polyphagous parasitoid of cereal aphids (Hemiptera: Aphididae)
Authors: Cameron P. J. , Powell W. , Loxdale H. D. 
Published: July 2009

AbstractAphidius erviHal. parasitised natural populations ofAcyrthosiphon pisum(Harris),Sitobion avenae(F.) andMicrolophium carnosum(Buckt.) in Britain but parasitised few examples ofS. avenaeplaced on trap plants in winter wheat, nettle-grass edge areas or lucerne-wheat strip crops. In laboratory experiments,Aphidius ervireared fromAcyrthosiphon pisumdid not parasitiseM. carnosum, and significantly fewer mummies were formed onS. avenaethan onA. pisum. After rearingAphidius ervifor 4–5 generations onS. avenae, similar numbers of mummies were formed on both hosts. The switch of hosts fromAcyrthosiphon pisumtoS. avenaewas associated with the loss of certain parasitoid esterase enzyme bands revealed following electrophoretic separation of parasitoid proteins. Slow adaptation to new aphid hosts by polyphagous parasitoids such asAphidius ervimay reduce the usefulness of reservoirs as a source of beneficial species.
Movement Patterns of the testse fly Glossina palpalis palpalis (Robineau-Desvoidy) (Dipter: Glossinidae) around villages in the pre-forest Zone of lvory Coast
Authors: Randolph Sarah E. , Rogers David J. 
Published: July 2009

AbstractThe movement patterns of Glossina palpalis palpalis (R.-D.) around villages in Ivory Coast were investigated by means of mark-release-recapture studies at two different sites. At one site, Congo Aboisso I, there appears to have been a single fly population based on the village, with an asymmetric ebb and flow of flies between the village and the surrounding bush; flies tended to remain in or around the village once they had arrived there. At the other site, Degbézéré, on the other hand, there were two populations, one centred on the village and the other on a nearby lake, with considerable exchange between the two. It is suggested that flies go to Degbézéré Village and remain there to feed, primarily on domestic pigs, and females return to the lake briefly to larviposit; males stay longer at the lake, perhaps to increase their chances of mating with emerging females. Long-distance movement of flies between villages, and also an analysis of the spatial pattern of fly movement between Congo Aboisso I and the surrounding bush, shows that human activity may affect the pattern of tsetse movement. Flight activity, and the consequent fly movement, was related to the nutritional status of the flies; males with greater fat content undertook more flight activity and thus tended to move further away from the village. The implications of these results for attempts at local trypanosomiasis control are discussed.
Nuclear magnetic resonance spectroscopy for studying the development and detection of the grain weevil,Sitophilus granarius(L.) (Coleoptera: Curculionidae), within wheat kernels
Authors: Chambers J. , McKevitt N. J. , Stubbs M. R. 
Published: July 2009

AbstractA novel non-destructive method was devised for studying the development of insects hidden within individual wheat grains using a standard nuclear magnetic resonance (NMR) spectrometer. The development ofSitophilus granarius(L.) at 25°C and 70% RH was studied from egg-laying to emergence by NMR, X-radiography and weighing. The results of the three methods correlated quite well. Neither the NMR nor the X-radiation appeared to harm the insects. The NMR method did not usually detect the insects until they were in the third larval instars, but after that the areas of the two NMR peaks observed with each infested grain followed a pattern which was readily interpreted in terms of the insect development. The major NMR peak was found to be due almost wholly to water and the minor peak to lipid, and the size of the major peak obtained with adults was close to that expected on the basis of their water content. The movement of some of the insects within the grains was observed for short periods and appeared to be characteristic of each developmental stage. Preliminary work with a less sophisticated NMR machine showed that it is possible in a single scan to detect ten grains infested withS. granariuslarvae in a batch of 500 grains, but further work is required to see whether single eggs can be detected. The results obtained in this study were sufficiently encouraging for a wide variety of other areas to be suggested in which use of NMR might help to solve some entomological problems.
Variability of vigour between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) and its implications for laboratory experimentation
Authors: Lenz M. 
Published: July 2009

AbstractGroups of Coptotermes acinaciformis (Froggatt) originating from six colonies, three taken from each of two widely separated localities in northern Australia (Townsville and Darwin), were kept at population densities of 0·005, 0·001 or 0·020 g termites/ml. Survival and wood consumption of the groups after eight weeks followed a similar pattern in the colonies from both collection areas. Groups exhibited least vigour at the lowest population density, most vigour at the middle density and slightly less than maximum vigour at the highest density. However, the actual values for survival and wood consumption varied widely between colonies, irrespective of their origin. The implications of these and related results for laboratory experiments which rely on survival and wood consumption as indicators of termite vigour are discussed.
Genetic factors controlling flight performance and migration in the African armyworm moth,Spodoptera exempta(Walker) (Lepidoptera: Noctuidae)
Authors: Parker W. E. , Gatehouse A. G. 
Published: July 2009

AbstractThe existence of a genetic component in the determination of flight capacity suggested by the results of previous experiments on the effects of environmental factors on flight performance inSpodoptera exempta(Walker) was confirmed by successful selection for and against the capacity for prolonged flight. The results of selection experiments were consistent with those expected when a polygenic character is subjected to directional selection. Heritability estimates for flight duration were 0·4 for overall heritability (mean offspring on mid parent regression) and 0·5–0·9 for single sex offspring on female and male parent regressions, demonstrating that flight capacity has a substantial additive genetic component. Although there can be no doubt that genetic factors play a major role in the control of migration inS. exempta, it is not yet clear whether flight capacity is a continuously varying character or whether discontinuous variation in the form of a genetically controlled flight polymorphism is involved. It is suggested that the life-history strategy ofS. exemptais adapted to maximise dispersal in the rains when a massive extension of favourable habitat occurs, and to maintain populations in those habitats which remain favourable in the dry season. The present evidence suggests that this strategy is achieved by cyclic selection of genetically determined variability in potential flight capacity.
Baseline responses of United Kingdom field populations of Macrosiphum euphorbiae (Thomas) and Brevicoryne brassicae (L.) (Hemiptera: Aphididae) to demeton-S-methyl
Authors: Furk C. , Roberts H. 
Published: July 2009

AbstractBaseline responses of United Kingdom field populations of Macrosiphum euphorbiae (Thomas) and Brevicoryne brassicae (L.) to demeton-S-methyl were investigated using the FAO-recommended dip-test bioassay. Dose-response lines were produced, and discriminating doses for the two species were derived from the results (320 and 500 mg a.i./litre, respectively) and validated by testing further field populations at those single doses. Of the 1620 individuals of M. euphorbiae and 330 of B. brassicae tested, none survived the discriminating doses.
Revisionary notes on the New World genera of cercopid froghoppers (Homoptera: Cercopoidea). III. The genus Isozulia
Authors: Fennah R. G. 
Published: July 2009

AbstractThe genus Isozulia is re-characterized and compared with Aeneolamia. Two species are transferred from Aeneolamia to become I. astralis (Distant) comb. n. and I. christenseni (Lallemand) comb. n., and I. flamen Fennah is reduced to a subspecies, I. astralis flamen, stat. n. Two populations from Ecuador and Peru are described as new species, I. minor sp. n. and I. charaxus sp. n., respectively, and a population of I. christenseni in Jujuy Province, Argentina, is recognised as a distinct subspecies, I. c. jujuyana subsp. n. Both this subspecies and I. minor are reported as attacking sugarcane.
A new species of Ferrisia (Hemiptera: Pseudococcidae) on cassava (Manihot esculenta) from Paraguay and on ragweed (Ambrosia tenuifolia) from Argentina
Authors: Williams D. J. 
Published: July 2009

AbstractFerrisia meridionalis sp. n. is described from Paraguay on cassava and from Argentina on ragweed (Ambrosia tenuifolia). Characters are given to separate it from F. virgata (Cockerell) with which it may easily be confused in life in South America on cassava.
Factors affecting resistance to insecticides in house-flies,Musca domesticaL. (Diptera: Muscidae). IV. The population biology of flies on animal farms in south-eastern England and its implications for the management of resistance
Authors: Denholm I. , Sawicki R. M. , Farnham A. W. 
Published: July 2009

AbstractWays in which the bionomics and dynamics of populations ofMusca domesticaL. can influence the development of insecticide resistance, and how resistance genes spread within and between farms was investigated in a three-year study of the biology and movement of flies on 63 pig-rearing farms in south-eastern England. House-flies survived winter only on 12 ‘overwintering’ farms where they bred in heated pig-rearing houses (‘closed buildings’) throughout the year. In late spring they appeared out doors, and their descendents founded populations on neighbouring ‘summer’ farms where pigs breed only in unheated (‘open’) buildings. There, flies reached peak numbers in August–September and died out by mid-November. Gene flow within and between farms was studied indirectly by mark-release-recapture of colour-marked adults, and directly by monitoring the diffusion of the visible marker genebwb(brown body) introduced into indigenous house-fly populations. Although movement between open buildings within a farm was unrestricted, dispersal between farms was limited, and gene flow between even adjacent closed buildings was indirect, and required more than one generation. Likewise, indirect and gradual gene flow during summer probably accounted for the similarity in type and frequency of other independent genetic markers of local overwintering populations. Thus closed buildings played a key role in house-fly ecology and population genetics. Unfortunately, control with persistent insecticides in these buildings ensures efficient resistance selection, ultimately resulting in its spread to all pig farms. Less selective control practices are needed at these sites.
Tanaostigmodes cajaninae LaSalle sp. n. (Hymenoptera: Tanaostigmatidae), a potential pest of pigeon pea in India
Authors: Lateef S. S. , Reed W. , LaSalle J. 
Published: July 2009

AbstractTanaostigmodes cajaninae LaSalle sp. n., the larvae of which feed in pods of pigeon pea (Cajanus cajan), is described. This insect, which also feeds on the weeds Atylosia spp. and Rhynchosia spp., has reached pest status on ICRISAT's research farm in Andhra Pradesh, India, where more than half of the pods on the late-maturing pigeon pea crops may be infested. However, surveys of the crops in farmers' fields in India showed that, although this insect is widespread, it is not yet a serious pest. The abnormal populations of this insect on the ICRISAT research farm appear to be associated with an abundance of its wild hosts, the availability of pigeon pea pods for many months in each year and the use of endosulfan, which does not control the pest but reduces its parasites. The potential for T. cajaninae to become a major pest in farmers' fields is discussed, and control measures are suggested.
Effects of temperature on the development of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae)
Authors: Miller Gareth W. , Isger Mark B. 
Published: July 2009

AbstractThe effect of constant and sinusoidally cycling temperatures on the durations of combined egg and larval development and of pupal development of Liriomyza trifolii (Burgess) was studied. The observed and estimated durations accorded well using 147·5 day-degrees above 10 1°C for eggs and larvae and 138·7 day-degrees above 10·8°C for pupae. A few pupae survived for 76 days in outdoor cages during a winter in southern England. Eggs hatched at 6–16°C (cycling), but larvae did not complete their development under this regime. Adults emerged from pupae at 6–16°C, and a few deformed adults emerged after 65 days at 11·5°C (constant). Some pupal development was detectable at 8°C. Pupae exposed to 1·1°C for 20 days all died, but some adults emerged at 14–26°C from pupae that had been kept at 1·1°C for 15 days.
Control of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in Egypt by mating disruption using hollow-fibre, laminate-flake and microencapsulated formulations of synthetic pheromone
Authors: Critchley B. R. , Campion D. G. , McVeigh L. J. , McVeigh E. M. , Cavanagh G. G. , Hosny M. M. , Nasr EL-Sayed A. , Khidr A. A. , Naguib M. 
Published: July 2009

AbstractHollow-fibre, laminate-flake and microencapsulated formulations of the synthetic sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-7, 11-hexadecadienyl acetate) of Pectinophora gossypiella (Saunders) were compared in large-scale mating disruption trials in Egypt in 1982. Fifty-hectare blocks of cotton were treated at regular intervals throughout the season with the formulated pheromone as the sole means of controlling the pest. The pheromone treatments were compared with conventional insecticide spray treatments in other 50-ha blocks of cotton sited in the same localities. Comparisons of numbers of infested flowers and green boils, open boll counts, crop development, yield of seed cotton, lint quality and seed damage in pheromone-and insecticide-treated blocks, showed that adequate levels of control were achieved using the pheromone formulations, which were equal in effect to the insecticide sprays. Beneficial insects were found in greater numbers in the pheromone-treated areas than in areas treated with insecticides.
Colony development and alate production in Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) on winter wheat
Authors: Cannon R. J. C. 
Published: July 2009

AbstractAn ecological study of summer populations of Metopolophium dirhodum (Walker) on winter wheat, was carried out near Bedford, UK, in 1978–80. Alate production (as percentages of alatiform fourth-instar nymphs) followed a consistent and synchronous three-phase pattern: with increases to 50% in early June in 1978–80 and 90% in late July in 1978–79. The proportions of winged offspring deposited by apterous parents also showed a similar increase, changing from 5% on 14–20 June to 91% on 5–11 July. Alate parents deposited mostly (75%) wingless offspring. Frequency distributions for nymph batch sizes were obtained for both morphs in 1979. Alate deposition was bimodally distributed. For apterous aphids, the fourth instar was the main dispersal stage. The numbers of adult apterae expressed as proportions of the total population were generally lower in 1979 than in 1978. The numbers of colonies increased sharply between 19 and 21 June in 1978 and 1979, and remained at similar levels to each other until at least 5 July. Colony and population numbers were highly significantly correlated over certain periods in 1978 and 1979. Colonies with >20 aphids increased sharply in numbers after 6 July, probably as a result of changing aptera dispersiveness. An estimate of mean colony size in 1979 showed a well-defined 14-day plateau phase. Changes in population alate production and changes in the proportions of winged offspring (from apterous parents) are discussed in relation to colony development. It is considered that increases in colony size produce colony-specific patterns of alate production.
An experimental evaluation of conventional control measures against the sheep tick, Ixodes ricinus (L.) (Acari: Ixodidae). II. The dynamics of the tick-host interaction
Authors: Randolph Sarah E. , Steele Gordon M. 
Published: July 2009

AbstractThe experimental manipulation of separate, but originally identical, populations of Ixodes ricinus (L.) by applying three conventional tick control measures in different enclosures on naturally infested moorland in Wales allowed the elements of the tick-host interaction to be analysed quantitatively and the effectiveness of the control methods to be compared. From the relationship between the sheep stocking density and the numbers of questing ticks picked up by fortnightly blanket-dragging in each enclosure, the death rate of ticks during their activity season and the rate of contact between sheep and ticks were calculated. From this, it was possible to investigate the effect of different stocking densities on the feeding success of ticks. A major factor determining the much lower contact rate for larvae than for nymphs was the different spatial distribution of questing ticks, clumped for larvae and random for nymphs. The non-random use by sheep of the three different vegetation zones in the paddock resulted in the highest contact rate between sheep and ticks in the pasture area, but tick survival was apparently highest in the bog area. Combining these factors resulted in the prediction that the bracken area was the least favourable habitat for ticks. In the two enclosures where the sheep were not treated with acaricide the mean tick loads on the sheep were similar, but the lower overall use of the pasture by the sheep in the low stocking density enclosure (2/ha) resulted in slightly lower tick loads there compared with those in the high stocking density enclosure (4/ha). The numbers of ticks counted in the second year showed that pasture spelling was the most effective control method, acaricide treatment was less effective, and the benefits of halving the stocking density were marginal. The implications of these results for control strategies are discussed.
Responses of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), to carbon dioxide and host odours. I. Activation
Authors: Warnes M. L. , Finlayson L. H. 
Published: July 2009

AbstractLaboratory experiments were carried out to investigate the effect of carbon dioxide and breath odours on the flight activity of Stomoxys calcitrans (L.). The flies responded to an increase in carbon dioxide concentration by an increase in flight activity (measured as the number of flights or the number of take-offs). The extent of this response was dependent on the period of starvation before exposure and the level of the increase in the carbon dioxide concentration. Flies rapidly habituated or adapted to new levels of carbon dioxide. Expired human breath elicited a greater increase in flight activity than would be predicted from its carbon dioxide content, and it was shown that the increased activity was caused by breath odours acting synergistically with an increase in the carbon dioxide concentration.
Genetics of an esterase associated with resistance to organophosphorus insecticides in the sheep blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)
Authors: Hughes P. B. , Raftos D. A. 
Published: July 2009

AbstractElectrophoresis was used to characterize the esterases in Lucilia cuprina (Wiedemann). Of the 16 esterase bands visualized, only one was associated with resistance to organophosphorus insecticides. In laboratory reference strains, the esterase E3 was consistently found in both susceptible and heterozygously resistant flies, but was absent from homozygously resistant flies. It was postulated that resistant flies possessed a non-staining form of E3, designated E3null. Genetic analyses mapped the locus for E3null to a position in the same region as the gene for organophosphorus resistance. No recombinants between the genes for resistance and E3null were detected. In field populations of L. cuprina from several areas in Australia, a close association was found between the frequency of E (0·97) and the proportion of flies resistant to organophosphorus insecticide (0·967). This association suggests that E3null represents the product of a major resistance gene in terms of the ‘mutant ali-esterase’ theory. E3 as found in susceptible blowflies, represents the ‘original’ ali-esterase, the gene for which mutated to one coding for E3null. This mutant enzyme can hydrolyse organophosphates more efficiently than E3 but has lost the ability to hydrolyse 1- and 2-naphthyl acetate (the substrates used to visualize the esterases after electrophoresis).
Pseudococcus mandio sp. n. (Hemiptera: Pseudococcidae) on cassava roots in Paraguay, Bolivia and Brazil
Authors: Williams D. J. 
Published: July 2009

AbstractPseudococcus mandio sp. n. is described from the roots of cassava in Paraguay, Bolivia and Brazil. In Paraguay, it is probably associated with wilting of the plant and, in common with most mealybugs, it appears to be a phloem-feeder. There is evidence of sufficient phloem in the roots, and this may be identical with the phloem of the stems. The mealybug is related to P. affinis (Maskell) in possessing swollen hind femora with numerous translucent pores, and discoidal pores around the eyes, but the oral rim ducts are either few or absent entirely.