bluuebunny/crossref_metadata_2025_split huggingface dataset:
Habitat associations and seasonal abundance of coprophilous coleoptera (Staphylinidae, Hydrophilidae and Histeridae) in the Hluhluwe region of South Africa
Authors: Davis Adrian L. V. , Doube Bernard M. , McLennan Paul D. 
Published: July 2009

AbstractA total of 134 species of Coleoptera (100 of staphylinids, 13 of hydrophilids and 21 of histerids) was extracted from pads of cattle dung placed in four contrasting habitats in both Hluhluwe Game Reserve, Natal, South Africa, and the surrounding pastoral regions. Pads were exposed to colonists for 24 h on eight occasions over one year. Forty-six species and species complexes were captured in numbers sufficient to permit analysis of their distribution patterns. Of 27 species significantly influenced by vegetation type, 22 were more abundant in unshaded situations and five more abundant in situations shaded by high profile vegetation. The total numbers of individual predatory staphylinids were evenly distributed between vegetation types, but members of coprophagous staphylinid and other predatory taxa were more numerous in unshaded situations. Of 13 species significantly influenced by soil type, six were more abundant on clay and seven more abundant on deep sand. The total numbers of individual coprophagous oxyteline staphylinids were greater on clay than on sand, but the members of predatory taxa, including staphylinids, were evenly distributed across soil types. Of 14 species showing significant seasonal changes in abundance, 13 were more abundant in hot wet months and one in cool dry months. The total numbers of hydrophilid individuals were greater in the cool dry season, but the other taxa were active predominantly in the rainy season. Most species were present in similar numbers in both the game reserve and pastoral regions. Enclosure of dung pads within wiremesh cones to exclude large dung-burying beetles resulted in reduced colonization by most beetle species regardless of their size.
Cardiochiles (Hymenoptera: Braconidae), a parasitoid of lepidopterous larvae, in the Sahel of Africa, with a review of the biology and host relationships of the genus
Authors: Huddleston T. , Walker Annette K. 
Published: July 2009

AbstractIn the ecologically sensitive Sahel of West Africa, two major crop pests, Helicoverpa armigera (Hübner) and Heliocheilus albipunctella (de Joannis), are attacked by Cardiochiles variegatus Szépligeti and C. sahelensis sp. n., respectively. The twelve Cardiochiles species present in the Sahel are revised, and a key is given for their identification. Five of these species (C. calvus sp. n., C. coelofrons sp. n., C. exiguurus sp. n., C. nixoni sp. n. and C. sahelensis sp. n.) are described, and C. striatus Brues is made a synonym of C. punctatus Szépligeti. Host relationships of the genus worldwide are discussed and the host records, principally involving Pyralidae and Noctuidae, collated. The known biology is summarized from the literature on the North American species C. nigriceps Viereck, and a comprehensive bibliography on the genus is given.Dans la région écologiquement difficile du Sahel de l'Afrique de l'Ouest, on a découvert que deux importantes variétés d'insectes nuisibles à la culture, Helicoverpa armigera (Hübner) et Heliocheilus albipunctella (de Joannis), sont attaquées respectivement par Cardiochiles variegatus Szépligeti et C. sahelensis sp. n. Les douze espèces de Cardiochiles qui se trouvent dans la région du Sahel sont réétudiés, et une clé est formulée afin de les identifier. Cinq de ces espèces (C. calvus sp. n., C. coelofrons sp. n., C. exiguurus sp. n., C. nixoni sp. n. et C. sahelensis sp. n.) sont décrites, et C. striatus Brues devient synonyme du C. punctatus Szépligeti. Les rapports universels de ces genres d'hôtes sont discutés ainsi que la comparaison des rapports d'observation, principalement en ce qui concerne les pyralides et les noctuides. La biologie actuelle est resumée de la littérature sur l'espèce C. nigriceps Viereck nord américain et une vaste bibliographie du genre est présentée.
Influence of diet on the survival and wood consumption ofPorotermes adamsoni(Froggatt) (Isoptera: Termopsidae) at different temperatures
Authors: Lenz M. , Barrett R. A. , Williams E. R. 
Published: July 2009

AbstractSurvival and wood consumption were measured for laboratory groups ofPorotermes adamsoni(Frogg.) maintained over a range of constant temperatures from 8 to 29°C. The termites were fed on sound blocks ofPinus radiata, Eucalyptus regnans, decayedE. ?viminalis, and outer (sound) and inner (decayed) heartwood ofE. pauciflora. Above 21 °C, diet influenced the pattern of survival, wood consumption and wood consumption adjusted for survival, resulting in a significant temperature × timber interaction. In the upper range of the temperatures used, the termites survived in larger numbers or for longer periods on decayed than on sound wood and ate more of it. From the results, it is clear that difficulties arise when employing laboratory data to estimate feeding activity of termite populations in the field. Knowledge of the correlation between the performance of termites in laboratory groups with that of members of a field colony is still sparse.
Factors affecting uptake and loss of diflubenzuron in the tsetse flyGlossina morsitans morsitansWestwood (Diptera: Glossinidae)
Authors: Clarke L. 
Published: July 2009

AbstractInterference with reproduction inGlossina morsitans morsitansWestw. by diflubenzuron depends on a variety of factors that influence its uptake and loss from the female fly. The duration of its eftect depends on the site and method of application to the fly as well as the amount of material applied. In nulliparous females, loss of diflubenzuron was by excretion, but as the fly aged approximately 50% of the material remaining within the fly was lost with each larviposition. Following injection, the rate of loss of diflubenzuron by excretion was twice that from flies treated topically, but in neither was it directly related to the amount of diflubenzuron within the fly. Loss to the in utero larva, however, was governed by the amount of material within the fly, at least 9 ng diflubenzuron being necessary for production of an abnormal offspring. In injected flies, the overall loss was twice that from flies treated topically on the dorsal thorax and similar to those treated topically on the ventral abdomen. This difference in the rate of loss from topically-treated flies seems to be related to the amount of material available on the surface of the fly, the cuticle apparently acting as a storage site from which there is a gradual release of diflubenzuron into the fly.
Survival and dispersal of young larvae of Chilo partellus (Swinhoe) (Lepi-doptera: Pyralidae) in two cultivars of sorghum
Authors: Chapman R. F. , Woodhead S. , Bernays E. A. 
Published: July 2009

AbstractThe establishment and survival of larvae of Chilo partellus (Swinh.) on two sorghum cultivars in the six days after hatching was investigated in the field in India. During this period relatively few larvae are present outside the whorls of the plants, and the numbers present six hours and three days after hatching are proportional to the numbers hatching. The number of larvae in the plants declines during these first three days, but subsequently is stable. Some dispersal to adjacent plants occurs during this period and, at the plant spacing used, approximately seven plants were infested by larvae from a single egg-mass of 40 eggs. The relative susceptibilities of the two cultivars, IS 1151 and IS 2205, altered with the age and size of the plants. This is a vulnerable period in the life-history of the insect and attention should be focused on it in developing resistant cultivars, but because the susceptibility of the plants changes with age it is important to decide the age at which protection would have the greatest economic value.
Possible sources of outbreaks of the armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in East Africa at the beginning of the season
Authors: Tucker M. R. 
Published: July 2009

AbstractPossible sources of adults of Spodoptera exempta (Wlk.) giving rise to outbreaks in East Africa at the beginning of the season were estimated by assuming downwind displacement and using the technique of backtracking. The accuracy of backtracks was limited by the availability of suitable weather data, but they provided a reasonably objective means of analysis. Eastern Kenya and eastern Tanzania were found to be the most likely source areas for moths. Migration from Ethiopia was very unlikely. Immigration from southern Somalia into Kenya, and from Malawi, Zambia or northern Mozambique into southern Tanzania was possible in a few years. In most years, there were likely to be sources in Kenya or Tanzania, probably of low density and in places suitable for the larvae to survive the dry season.
Carbamate and organophosphate resistance inCulex pipiensL. (Diptera: Culicidae) in southern France and the significance ofEst-3A
Authors: Wood R. J. , Pasteur N. , Sinégre G. 
Published: July 2009

AbstractThree French strains ofCulex pipiensL. were compared at the fourth larval instar for tolerance to organophosphate and carbamate insecticides, with and without the addition of synergists (the oxidase inhibitors piperonyl butoxide and CGA 84708) (a propynyl compound) and the carboxylesterase inhibitors triphenyl phosphate (TPP) andS,S,S-tributyl phosphorotrithioate (TBPT). The S54 strain was resistant to all the organophosphates tested (chlorpyrifos, malathion, monocrotophos and profenofos) compared to the susceptible LA VIS strain but only slightly tolerant to the two carbamates (carbaryl and naphthyl phenylcarbamate). The MAURIN strain was resistant to all the insecticides, including the carbamates, at a higher level. The action of chlorpyrifos and malathion on S54 was very strongly synergised by TBPT, less strongly by TPP and not at all by piperonyl butoxide. In fact, resistance was enhanced by piperonyl butoxide, as was resistance to monocrotophos and profenofos by CGA 84708. No synergist had much effect on the MAURIN strain, although TPP slightly increased the toxicity of malathion, and piperonyl butoxide and CGA 84708 slightly increased the toxicity of carbaryl. The toxic effect of carbaryl was also increased by the addition of extra acetone. Electrophoretic studies showed that the carboxylesterase enzyme coded by geneEst-20.64(which is in linkage disequilibrium withEst-3Aand acts as a marker for it) was absent from LA VIS but present in the resistant strains; but, whereas S54 was monomorphic for the gene, MAURIN was polymorphic (frequency 0·5). It is concluded that organophosphate resistance in S54 was due to detoxification by carboxylesterase wherease organophosphate and carbamate resistance in MAURIN had a strong non-metabolic component, possibly an insensitive acetylcholinesterase.
Studies of elemental composition as a biological marker in insects. II. The elemental composition of apterae of Rhopalosiphum padi (L.) and Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) from different soils and host-plants
Authors: Bowden J. , Sherlock P. L. , Digby P. G. N. , Fox J. S. , Rhodes J. A. 
Published: July 2009

AbstractEnergy-dispersive X-ray spectrometry was used to make quantitative determinations of the elemental composition of plasma-ashed apterous individuals of Rhopalosiphum padi (L.) and Metopolophium dirhodum (Walker). R. padi was reared on 24 plant–soil combinations and M. dirhodum on nine plant-soil combinations. Analyses were done for 12 elements: Na, Mg, Al, P, S, Cl, K, Ca, Mn, Fe, Cu and Zn. Principal components analyses of individuals showed no distinction, in either aphid species, between insects reared on any plant–soil combination, whether all elements, elemental sub-sets, soil sub-sets or host-plant sub-sets were considered. When group means (mean for all individuals from a particular plant-soil combination) were used in principal components analyses, five groups of R. padi could be distinguished from the other 19, although neither set could be further separated. Four of the five distinguishable groups were from plants that grew particularly poorly, and the fifth was from plants in a soil in which all host-plants grew less well than in other soils. There were no distinct separations between groups of M. dirhodum, though there were slight indications that soils were distinguishable. In both R. padi and M. dirhodum, elemental differences involved the minor elements, particularly Mn, Fe, Cu and Zn. The uniformity of elemental content in the apterae of both aphid species may be a consequence of genetic uniformity within clones of parthenogenetically reproducing species.
Electrophoretic study of enzymes from cereal aphid populations. III. Spatial and temporal genetic variation of populations ofSitobion avenae(F.) (Hemiptera: Aphididae)
Authors: Loxdale H. D. , Tarr I. J. , Weber C. P. , Brookes C. P. , Digby P. G. N. , Castañera P. 
Published: July 2009

AbstractNinety-two individuals ofSitobion avenae(F.) collected throughout Britain in 1979 and 1980, were cloned and investigated genetically by electrophoresis of 14 enzymes representing 26 loci. Percentage polymorphism (P) differed considerably between years, 64% (16/25 loci) in 1979 and 19% (5/26) in 1980, whereas average heterozygosity () was low (ca. 2%) in both years and confined mainly to one locus, EST-1. The prevalence of homozygous allozyme variation supports ecological findings suggestingS. avenaeto be largely anholocyclic in Britain. In 1981 and 1982, large populations, sampled from 11 sites in Britain and Spain, were examined at 13 loci.ranged from 2 to 7·6%, with heterozygosity restricted again mainly to EST-1. Some alleles were unique to certain geographical regions (including Britain or Spain); others showed significant spatial, and in two British populations examined in successive years, temporal frequency differences. Calculating Nei’s genetic identity (I) and distance (D) coefficients for each population pair mostly gaveI>0·8,D<0·2 with overall means (± s.e.m.) of 0·896 ± 0·006 and 0·111 ± 0·006, respectively, which are comparable with geographical population values for other insects.Dwas poorly correlated with geographical distance, although values were slightly greater (ca. 0·025) for international population comparisons and did not overlap on a principal coordinates plot. The overall population similarity suggests substantial inter-population gene flow; geographical barriers may have restricted movements but seemingly have not led to allopatric race formation. P andvalues resemble those for many other aphids, but H values are lower than typically found in other insects. Possible causes of this heterozygote deficiency are discussed.
The role of 1-octen-3-ol, acetone and carbon dioxide in the attraction of tsetse flies, Glossina spp. (Diptera: Glossinidae), to ox odour
Authors: Vale G. A. , Hall D. R. 
Published: July 2009

AbstractIn the Zambezi Valley of Zimbabwe, the numbers of Glossina morsitans morsitans Westwood and G. pallidipes Austen electrocuted on grids placed across their flight paths as they arrived at various natural and synthetic odour sources demonstrated that ox odour comprises two broad fractions of attractants. One fraction can be trapped by a charcoal filter and, in part, consists of 1-octen-3-ol. A more volatile fraction passes through the filter and, in part, consists of carbon dioxide and acetone. Levels of acetone and 1-octen-3-ol in ox odour varied considerably, up to maxima of 24 mg/h and 0·025 mg/h, respectively. Catches were roughly doubled when octenol at 0·5 mg/h was added to ox odour, but declined when the dose was increased to 50–500 mg/h. A synthetic odour consisting of 2 litres of carbon dioxide/mm, 5 mg of acetone/h and 0·05 mg of 1-octen-3-ol/h, was nearly as effective as ox odour for G. m. morsitans but only half as effective as ox odour for G. pallidipes. Increases to the doses of each attractant in the synthetic odour increased the catches, to roughly double those with ox odour. Data for other Diptera are also presented.
Theoretical models of the use of insecticide mixtures for the management of resistance
Authors: Curtis C. F. 
Published: July 2009

AbstractSimple one- and multi-generation models are used to show the essential features of the dynamics of selection for resistance to one insecticide or two unrelated insecticides in insect populations, part of which are unexposed to either compound. The use of a mixture appears advantageous provided that resistance is not fully dominant, but, if it is, linkage disequilibrium builds up rapidly and nullifies the advantage of the mixture
Relationship between red scale, Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae), and its natural enemies in the upper and lower parts of citrus trees in South Africa
Authors: Samways M. J. 
Published: July 2009

AbstractIn mature Valencia orange trees at three sites in the Transvaal lowveld, there was a variable differential between levels of Aonidiella aurantii (Maskell) in the upper and lower parts of the trees. At one site there were high scale levels in the crowns of the trees as a result of past poor chemical spray procedure. In recent years, pest management has maximized on the use of natural enemies, especially Aphytis spp. However, the natural enemies have not been able to ameliorate the crown problem. At generally high levels of Aonidiella aurantii, the natural enemies were ableonly, more or less, to maintain the average overall level of the scale from one year to the next; they could not bring it down. This arose each year from too many scales escaping parasitism and reaching the relatively invincible adult stage early in the season. As the behaviour of the parasitoids was inversely density-dependent at these relatively high scale levels, this led to a greater increase in scale numbers, leading eventually to up to 90% of the population (excluding crawlers) being composed of adult females. The inverse density dependence was also partly because the majority of single scales escaped parasitoid attack. In the lowveld, it is a prerequisite that the density of A. aurantii first be lowered by an introduced natural enemy (e.g. the coccinellid Chilocorus nigritus (F.)) that attacks the adult stage and&sol; or by chemical means before maximal use is made of the regulatory influence of the existing natural enemies, particularly Aphytis spp.
The effect ofSitona discoideusGyllenhal (Coleoptera: Curculionidae) on lucerne yields in New Zealand
Authors: Goldson S. L. , Dyson C. B. , Proffitt J. R. , Frampton E. R. , Logan J. A. 
Published: July 2009

AbstractThe impact of injury by larvae and adults ofSitona discoideusGyllenhal on lucerne production was studied in two consecutive seasons at two adjacent sites near Christchurch, New Zealand. The root-feeding larvae were found to be more damaging than the adults; in the first cut in the 1982–83 season in a three-year-old stand, larvae reduced dry matter yield by 18%. In the wetter following season in a one-year-old stand, second and third cut losses of 43 and 30% dry matter production, respectively, were recorded. In both seasons, the lucerne had apparently substantially recovered from larval damage by the time of the last cuts. In the drier 1982–83 season, two cuts were taken compared with four in the 1983–84 season. Adult feeding was found to reduce second cut wet yields by 20–30% in the 1982–83 season but had no measurable effect in the 1983–84 season. In both seasons, manipulated ranges of larval densities showed that damage appeared only when larval populations were in excess of a distinct larval population density threshold. At larval densities less than this threshold, yield was unaffected; above the threshold, yield losses were independent of larval density. Such a yield response curve was found to be adequately described mathematically by a simple arctan model; this approach allowed the threshold to be further defined and overall estimates to be made of the yield losses arising from larval damage. The threshold occurred at about 1200 larvae/m2in the dry season and about 2100 larvae/m2in the wet season. This suggested moisture sensitivity and the possibility that the crop may enter a damage-induced dormancy related to that observed during a severe drought.
Meligethes heteropus Gerstaecker (Coleoptera: Nitidulidae), a new pest of bulrush millet in West Africa
Authors: Spriggs-Kirk A. H. 
Published: July 2009

AbstractVast populations of Meligethes heteropus Gerstaecker have recently been found on millet in Nigeria. The damage they cause is described and the previously unknown male is described and figured. The validity of characters previously used in the diagnosis of Meligethes is discussed.
An experimental evaluation of conventional control measures against the sheep tick,Ixodes ricinus(L.) (Acari: Ixodidae). I. A unimodal seasonal activity pattern
Authors: Steele Gordon M. , Randolph Sarah E. 
Published: July 2009

AbstractQuesting individuals ofIxodes ricinus(L.) on a naturally infested moorland in Wales were censused every fortnight from January 1981 to October 1982 by blanket-dragging, and feeding ticks were counted on the sheep hosts. The seasonal activity patterns for ticks in all three stages were unimodal, with nymphs and adults active between March and July, and larvae active between April and August. This unimodal, as opposed to the usually described bimodal, pattern is explained in terms of the long cold winters and short summers of this field site. The survival time of questing nymphs was calculated from an analysis of their changing lipid content during the activity season to be a maximum of four months, which is consistent with the other field observations. The precise identification of the pattern of activity, as well as being essential for the application of appropriately timed control procedures, is necessary for the interpretation of the tick-host interactions under various control regimes that were applied.
Spatial and temporal population patterns of Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) parasitoids (Hymenoptera: Aphelinidae and Encyrtidae) caught on yellow sticky traps in citrus
Authors: Samways M. J. 
Published: July 2009

AbstractParasitoids of Aonidiella aurantii (Maskell) on citrus in South Africa were monitored using two types of yellow sticky trap. One of these traps was highly efficient, being fluorescent with peak reflectance at about 530 nm. Aphytis spp. populations were low before February and high thereafter. Citrus surrounded by natural bush was an isolated reservoir of high host and parasitoid population levels. Aphytis spatial distribution within the orchard was extremely patchy, with over 100-fold differences in population levels over a distance of a few metres. This patchiness mirrored that of its host. This contagious spatial pattern was maintained despite 1000-fold seasonal changes in population levels. These temporal changes were characteristic and general throughout an orchard, and independent of patchiness. Initial Aphytis population levels did not dictate the final population level at the end of the season. Comperiella bifasciata Howard and its hyperparasitoid Marietta javensis (Howard) also showed clear seasonal population trends, but not of the same magnitude as those of Aphytis. There was no statistically significant correlation between the spatial distribution of one parasitoid with that of another, even between C. bifasciata and M. javensis. The patchiness of these two species was not correlated with overall host density. Aphytis and C. bifasciata were partially mutually exclusive. Aphytis was by far the most economically important of the parasitoids. Pest management practices, therefore, should aim at conserving the pool of Aphytis within the orchard as far as practicable.