bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of the mealybug Planococcus halli Ezzat & McConnell (Hemiptera: Pseudococcidae) commonly occurring on yams (Dioscorea spp.) in Africa and the West Indies
Authors: Cox Jennifer M. , Wetton Mark N. 
Published: July 2009

AbstractMultivariate analysis was used to demonstrate that specimens of Planococcus collected from yams (Dioscorea spp.) in both the West Indies and Africa can be differentiated from the similar P. ficus (Signoret) which occurs on figs, grapevines and pomegranates in the Mediterranean Basin, Pakistan, South Africa and Argentina. The specimens from yams are considered here to be a distinct species, to which the name P. halli Ezzat & McConnell is applied. Examination of material of both species reared on potato tubers at various temperatures showed that the differentiation is not a host-induced effect. Independent canonical variates analysis of the field-collected and reared material each showed clear differentiation of the two groups. However, the coefficients obtained for each character differed markedly between the analysis of the field-collected material and that of the reared material, and thus could not be used to assign individuals to groups. This difference in the values of the coefficients is considered to have been due to the peculiarities of individual populations, as the field-collected material included many genotypes while only three genotypes were represented by the reared material. A key and illustrations are provided for the separation of the two species.
The effect of colour on trap- and screen-orientated responses in Glossina palpalis palpalis (Robineau-Desvoidy) (Diptera: Glossinidae)
Authors: Green C. H. 
Published: July 2009

AbstractThe importance of colour in the attraction of Glossina palpalis palpalis (Robineau-Desvoidy) to trapping devices was investigated in the Ivory Coast. Biconical traps were tested with the normally royal blue lower cone replaced with one of 25 differently coloured cloths. Royal blues were consistently the best colours for traps; yellow and orange were the worst, catching less than 1% as many as the best royal blue. Modelling trap data from the spectral reflectivities of the colours used showed that blue wavelengths contributed positively, and ultraviolet and green-yellow-red negatively, to trap performance. The responses to screens were studied using electric nets, deployed to catch flies both circling around and landing on the screen. The overall catch (of circling and landing flies) was greatest for royal blue screens, intermediate for yellow and green ones, and lowest for screens highly reflective of ultraviolet light; the total range of variation between colours was much smaller than was the case with traps. The relationship of catch to spectral reflectivity was similar to that described for trap score. An achromatic series of screens (black, white and greys) all attracted significantly fewer females than did royal blue screens, implying that attraction to blue depends on colour discrimination and not on intensity contrasts alone. For most colours, the majority of flies circled the screen without landing; with materials strongly reflecting ultraviolet, however, a high proportion of flies (especially females) landed.
Solitarization in the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae)
Authors: Gillett Sylvia D. 
Published: July 2009

AbstractThe rate at which gregarious nymphs of Schistocerca gregaria (Forskål) lose the tendency to form groups after different periods of isolation was measured. There was a marked loss of social grouping after isolation for 24 h. The fall in level of grouping was highly significantly correlated with the number of days the nymphs had been isolated. Further experiments showed that the extent of loss of grouping behaviour could be significantly modified by the length of time the nymphs spent in crowded conditions before they were isolated, but the density during previous crowding did not have a consistent effect on reduction in grouping. It had been previously considered that S. gregaria nymphs lose very little of their gregarious tendency once it is acquired; this is now shown not to be the case. The behaviour of this species is very responsive to the social environment, whether the locusts are learning to form groups or are losing that tendency.
The location of floral nectar sources by mosquitoes: the long-range responses of Anopheles arabiensis Patton (Diptera: Culicidae) to Achillea millefolium flowers and isolated floral odour
Authors: Healy T. P. , Jepson P. C. 
Published: July 2009

AbstractA 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.
Phenological development and seasonal distribution of the rutherglen bug,Nnysius vinitorBergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia
Authors: McDonald Garrick , Smith A. Mark 
Published: July 2009

AbstractPopulations ofNysius vinitorBergroth were studied from 1979 to 1982 in two weed hosts,Arctotheca calendulaandPolygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing floweringA.calendulaplants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared.P. aviculareattracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development ofN. vinitorin spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.
Aspects of the biology of Rastrococcus invadens Williams (Hemiptera: Pseudococcidae), a pest of fruit crops in West Africa, and one of its primary parasitoids, Gyranusoidea tebygi Noyes (Hymenoptera: Encyrtidae)
Authors: Willink E. , Moore D. 
Published: July 2009

AbstractRastrococcus invadens Williams, a serious pest of fruit crops in West Africa was studied under controlled conditions. The different stages of the mealybug are described and data given on development times, adult lifespan, fecundity, sex ratio and mortality rates. Similar data are also given for a primary parasitoid, Gyranusoidea tebygi Noyes. The parasitoid completed almost two generations for each one of the mealybug and had a female-biased sex ratio compared with a male-biased one for R. invadens. The parasitoid did not parasitize other species of mealybugs offered. G. tebygi was considered a suitable candidate for a biological control programme and was introduced into Togo in October 1987.
DDT resistance in Anopheles culicifacies Giles and A. subpictus Grassi (Diptera: Culicidae) from Sri Lanka: a field study on the mechanisms and changes in gene frequency after cessation of DDT spraying
Authors: Herath P. R. J. , Jayawardena K. G. I. , Hemingway J. , Harris J. 
Published: July 2009

AbstractThe frequency of DDT resistance in Anopheles culicifacies Giles in Sri Lanka remained relatively constant from the cessation of DDT use for malaria control in 1975 until 1982. From 1983 to 1986, the frequency of resistance decreased slowly but significantly. In contrast, the resistance gene frequency in A. subpictus Grassi declined between 1980 and 1983, after which the trend was reversed, and there was a significant increase in DDT resistance in 1984–86. This rise in DDT resistance cannot be attributed to positive DDT selection pressure as there has been little or no agricultural use of DDT during this period. It is also unlikely that the rise in resistance is due to pyrethroid selection as the quantity of pyrethroids used on the island is low and there is no evidence of pyrethroid resistance from WHO susceptibility tests. Studies with the synergists FDMC (4-chloro-α-(4-chlorophenyl)-α-(trifluoromethyl)benzenemethanol) and piperonyl butoxide indicated the involvement of DDT-dehydrochlorinase rather than oxidase in the resistance. This was confirmed by metabolism studies, as DDT-resistant adults of both A. culicifacies and A. subpictus showed an increase in the rate of DDE production, which was also correlated with an increase in glutathione transferase activity.
Age-grading methods in adult insects: a review
Authors: Tyndale-Biscoe M. 
Published: July 2009

AbstractThe literature on age-grading techniques of adult insects, published since 1968, is reviewed. The techniques described include those which deal with changes in the reproductive system, as well as somatic changes which take place with age. They also include techniques based on changes induced by wear and tear. Follicular relics found in different orders of insects are described, and their origin, fate and relative usefulness in age-grading studies are discussed. Attention is drawn to the formation of anomalous, or aberrant dilatations, particularly ones formed as a result of follicle resorption. The suitability of the various techniques to the study of different insect species is compared, and the advantages of using more than one type of age-grading method in the study of one species are discussed. Enough detail of each technique is given to permit field workers to choose and apply the technique most suitable for the study of the insect of their choice, and for the degree of accuracy required by them. Lists of species which have been studied by particular age-grading techniques, or combinations of them, are given. Finally, examples are cited of the types of problems entomologists have sought to solve, often successfully, using age-grading methods.
Encarsia bennetti sp. n. (Hymenoptera: Aphelinidae) from India, associated with the citrus black fly, Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae)
Authors: Hayat Mohammad 
Published: July 2009

AbstractThe aphelinid Encarsia bennetti sp. n. is described from material collected in India and associated with Aleurocanthus woglumi Ashby, a pest of citrus.
Adaptive significance of brood care of Copris diversus Waterhouse (Coleoptera: Scarabaeidae)
Authors: Tyndale-Biscoe Marina 
Published: July 2009

AbstractBrood care in Copris diversus Waterh. enhanced survival of progeny. Reallocation of dung from brood balls with no live progeny to brood balls containing live progeny was. a typical behaviour pattern in this species and resulted in fewer, larger brood balls. The advantage of this behaviour is that larger brood balls produced larger progeny, which in turn produced a greater number of offspring.
Distribution of moths of the Egyptian cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), in the Nile Delta interpreted from catches in a pheromone trap network in relation to meteorological factors
Authors: Nasr El-Sayed A. , Tucker M. R. , Campion D. G. 
Published: July 2009

AbstractRecords of daily catches of males of Spodoptera littoralis (Boisd.) at pheromone traps in or near the Nile Delta, Egypt, during 1979 and 1980 were used to investigate both the seasonal variation in catch and the possibility that migration, associated with particular weather systems, may significantly affect moth numbers in a particular area. Although more moths were caught in 1979 than in 1980, in both years there was a similar seasonal variation in catch, with low numbers in January and February followed by an increase to a maximum in June or August. There was no systematic seasonal change in the area of highest catch that would suggest seasonal migrations. On some nights, large increases in catch were associated with weather disturbances, notably windshift lines, suggesting that flying moths are sometimes redistributed by wind systems. Catches at two traps far from the main source area suggest that moths may have flown at least 50 km downwind from sources in the Nile Delta. The pattern of nightly catches at most traps indicated that build-up of local populations is the most important factor affecting the population dynamics of the pest but that some, mainly local, redistribution by wind systems takes place.
Comparative studies on the resistance of materials to species of Coptotermes (Isoptera: Rhinotermitidae). I. The susceptibilities of various plastics to C. acinaciformis (Froggatt) from Australia and C. formosanus Shiraki from China
Authors: Watson J. A. L. , Zi-Rong Dai , Barrett R. A. 
Published: July 2009

AbstractThe susceptibilities of 14 plastics formulations (four polyethylenes, one polypropylene, one polyester, two polyamides, one polyurethane and five poly(vinyl chlorides)) to attack by Coptotermes acinaciformis (Frogg.) and C. formosanus Shir. in the laboratory were broadly related to hardness and surface finish. Overall, C. acinaciformis inflicted more damage than C. formosanus, despite lower survival, but some formulations appeared more susceptible to C. formosanus than to C. acinaciformis.
The feeding behaviour ofSimuliumlarvae, and the development, testing and monitoring of the use of larvicides, with special reference to the control ofSimulium damnosumTheobald s.l. (Diptera: Simuliidae): a review
Authors: Walsh J. F. 
Published: July 2009

AbstractThe control ofSimuliumhas always relied largely on the use of insecticides against the larvae, and this is the case in the current large-scale Onchocerciasis Control Programme against the vectorS. damnosumTheobald in West Africa. Resistance to temephos has occurred in some vector species, and it is necessary to find alternatives to this preferred larvicide. In order to provide a frame of reference for the development of new larvicides or formulations, the literature relating to larval filter-feeding behaviour is first reviewed in detail. Then the physico-chemical conditions in larval habitats are outlined. The types of formulations and classes of insecticide used inSimuliumcontrol are considered, with particular attention being given to emulsifiable concentrate formulations and the reasons for their effectiveness. Particulate formulations, which have been recommended on environmental grounds, are also discussed. Techniques used in the screening of larvicides are considered, and it is concluded that flow-through systems are necessary; mini-gutter tests conducted using water and fauna from rivers to be treated are to be strongly preferred, followed by stream trials. Knowledge ofBacillus thuringiensisvar.israelensisas aSimuliumlarvicide is reviewed in detail. The environmental impact of control ofSimuliumlarvae, both in the tropics and the temperate zone, is extensively reviewed. Throughout, key features which might lead to improved larvicide formulations and testing procedures, together with serious gaps in our knowledge are emphasized.
Mealybugs of the genusRhizoecus(Hemiptera: Pseudococcidae) on African violets (Saintpauliaspp.), with a description of a new species from Thailand
Authors: Williams D. J. 
Published: July 2009

AbstractFour species of hypogeic mealybugs are known to infest African violets (Saintpauliaspp.). These areRhizoecus americanus(Hambleton),R. cacticans(Hambleton),R. dianthiGreen andR. saintpauliaesp. n. The last species has some striking characters and is described here from specimens fromS. ionanthain a nursery in Thailand. None of these species is known to occur on plants in their natural habitat, the mountainous areas of Kenya and Tanzania, where the survival of most of the 20 species ofSaintpauliais threatened. Although infestations ofR. dianthion African violets may be severe, the mealybugs only affect these and other potted plants in the extensive horticultural trade. A key is provided to separate the four species.
Development of a synthetic diet for Glossina (Diptera: Glossinidae)
Authors: Kabayo J. P. , Taher M. , Van Der Vloedt A. M. 
Published: July 2009

AbstractA semi-defined synthetic diet for Glossina spp. was developed and used successfully to rear G. palpalis palpalis (Robineau-Desvoidy) for five generations. The survival, fecundity and offspring size achieved were similar to those obtained when flies are fed on whole blood in vitro. The diet was also tested on G. morsitans morsitans Westwood, G. austeni Newstead and Stomoxys calcitrans (L.), and in all cases was satisfactory. The diet consists of commercially available ingredients and is the first such diet to be developed for obligate haematophagous insects.
Observations on the dispersal and survival of a population of Aedes lineatopennis (Ludlow) (Diptera: Culicidae) in Kenya
Authors: Linthicum K. J. , Bailey C. L. , Davies F. G. , Kairo A. 
Published: July 2009

AbstractAedes lineatopennis (Ludlow) is thought to be a vector and maintenance host for Rift Valley fever virus in Kenya and perhaps other parts of sub-Saharan Africa. Immature examples are often found in tremendous numbers in restricted, low lying habitats known as dambos. A dambo in Thika District, Central Province, Kenya, was artificially flooded to simulate the conditions occurring when this area naturally floods and induces the hatch of A. lineatopennis eggs. Observations on the dispersion and survival of the emerging adult population were made at a time when no other adult A. lineatopennis populations existed. More than 10% (87 511) of the estimated A. lineatopennis adults that emerged from the flooded dambo were collected during a 45-day period. The overall mean distance travelled by males in the 45 days after emergence was only 0·07 km. Female dispersal was interrupted but generally was with the prevailing wind. The overall mean distance travelled by females in the 44 days after emergence was 0·15 km. Mortality of both males and females was independent of age. The high daily survival rate of males (0·83) was not significantly different from that of the females (0·85).
Studies of elemental composition as a biological marker in insects. IV. The influence of soil type and host-plant on elemental composition of Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae)
Authors: Sherlock P. L. , Bowden J. , Digby P. G. N. 
Published: July 2009

AbstractWavelength dispersive X-ray fluorescence spectrometry was used to make quantitative determinations of the elemental composition of adults of Agrotis segetum (Denis & Schiffermüller) that had been reared on one of eight soil-plant combinations or a semi-synthetic diet. Robust-means principal components analysis (RMPCA) of the data for eight elements and all treatments (except for the semi-synthetic diet) separated the means of the groups by soil type, irrespective of host-plant. However, individuals could not be separated until the data were grouped into the two host-plant sub-sets. The main discriminant, Al, was of doubtful validity and was therefore excluded from the data which were reanalysed by RMPCA. This failed to discriminate either group means or individuals until each host-plant sub-set was analysed separately; then, individuals could be differentiated by soil type although not as distinctly as when Al was included in the data. There was, however, a clear separation of the sexes because of a higher content of K and lower content of Ca in females; these two elements, together with S and Cl, were the main discriminants of soil type. It is concluded that larval host-plant is a significant factor in the elemental composition of adults of A. segetum but limiting and confounding in respect of identification of soil type and, therefore, geographical source. This conclusion probably applies also to other similar polyphagous species, but specific differences in biology and behaviour may influence the applicability of the technique to field studies.
Responses of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), to carbon dioxide and host odours. II. Orientation
Authors: Warnes M. L. , Finlayson L. H. 
Published: July 2009

AbstractExperiments were carried out in a slow speed wind tunnel and in a moving air observation chamber on anemotactic and visual responses of Stomoxys calcitrans (L.). An increase in carbon dioxide concentration elicited an anemotactic response, which was enhanced by odours from expired human breath and odours from a live guineapig. Acetone vapour also elicited an anemotactic response, but acetic acid was repellent. The response to visual targets increased in proportion to the increase in flight activity induced by raising the concentration of carbon dioxide in the airstream. Cattle sebum had an arrestant effect but also elicited further searching activity.
Age distributions and reproductive status of declining and stationary populations of Glossina pallidipes Austen (Diptera: Glossinidae) in Zimbabwe
Authors: Van Sickle J. , Phelps R. J. 
Published: July 2009

AbstractAge structures and reproductive anomalies of two field populations of Glossina pallidipes Austen in Zimbabwe were compared. One population was treated with insecticide sprayed on odour-baited targets, while the other was left undisturbed. Both populations were sampled with F3 prism-type traps. Capture probabilities were higher for females in early stages of pregnancy than for those in later stages. Per-capita mortality rates were estimated from age distributions which had been corrected for rate of increase. The mortality rate steadily increased over time in the insecticide-treated area but remained roughly constant in the undisturbed area. Estimates of mortality had wide confidence intervals, and the mortality model is critically reviewed. No evidence was seen in the treated population for an increased incidence of abortion or other reproductive anomalies, or for a decrease in insemination rate.
Monitoring frequencies of insecticide resistance in Myzus persicae (Sulzer) (Hemiptera: Aphididae) in England during 1985–86 by immunoassay
Authors: Ffrenchconstant R. H. , DEVONSHIRE A. L. 
Published: July 2009

AbstractAn immunoassay for the carboxylesterase E4, which confers insecticide resistance in Myzus persicae (Sulzer), was used to monitor the distributions of E4 activity within samples comprising more than 5000 aphids from sites in eastern and southern England. The quantitative precision of this assay is an improvement on the subjective assessment of E4 band intensity on electrophoresis gels previously used. Activity distributions did not always show discrete components corresponding to S, R1, R2 or R3 variants and thus, though convenient, this classification should be used cautiously. Distributions derived by immunoassay of many insects from the field are best compared to those of laboratory-reared standards classified according to E4 quantity (V1-V64). Data from untreated crops are presented in this way and discussed in the light of previous surveys. A large proportion of aphids corresponding to the V8 variant (intermediate between ‘R1’ and ‘R2’ categories) were found, and frequencies of resistance differed on both a local and regional scale. The majority of aphids from treated crops had E4 activities equivalent to, or above, that of V16 (i.e. ‘R2’).