bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal population dynamics of the immature stages ofAedes africanus(Theobald) (Diptera: Culicidae) in Zika Forest, Uganda
Authors: Sempala S. D. K. 
Published: July 2009

AbstractThe seasonal population trends of the immature stages ofAedes africanus(Theo.), an important vector of yellow fever virus and other arboviruses, were studied in Zika Forest, Uganda, for two years during 1974–75. Data were collected from natural breeding places in tree holes and from bamboo pots placed 80 cm above the ground. Developing larvae and pupae were present at all times of year, and there were monthly, seasonal and annual fluctuations in density. These fluctuations followed the seasonal distribution of rainfall and were more marked in the natural breeding places, which were subject to irregular fluctuations in water level, than in the bamboo pots, which were constantly supplied with water. Thus, in addition to the drought-resistant eggs whose erratic hatching by instalments could ensure the presence ofA. africanusthroughout the year, there are probably also present at any given time females that are capable of ovipositing. As a measure of the seasonal population changes, it was found that both the percentage of positive containers index and the mean number per container index were almost equally sensitive.
Interactions between immature Aedes africanus (Theobald) and larvae of two predatory species of Toxorhynchites (Diptera: Culicidae) in Zika Forest, Uganda
Authors: Sempala S. D. K. 
Published: July 2009

AbstractStudies conducted in Zika Forest, Uganda, on the breeding interactions between Aedes africanus (Theo.) and two mosquito predators, Toxorhynchites brevipalpis conradti Grünb. and T. kaimosi (van Som.), revealed a significant reduction in the numbers of A. africanus larvae and pupae in tree holes that were also inhabited by the predator larvae. There was a tendency for seasonal peaks in numbers of A. africanus to be followed two months later by peaks in Toxorhynchites spp. Cannibalism appeared to play an important role in the regulation of the population size of the two species of Toxorhynchites. The implications of these results in relation to the possible use of Toxorhynchites mosquitoes for biological control of A. africanus and other mosquitoes breeding in tree holes are discussed.
Behaviour of newly hatched larvae of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) associated with their establishment in the host-plant, sorghum
Authors: Bernays E. A. , Chapman R. F. , Woodhead S. 
Published: July 2009

AbstractThe climbing behaviour of newly hatched larvae of Chilo partellus (Swinh.) on sorghum plants was studied in the laboratory and in the field in India. The upward movement is directed by light, while the final downwards movement into the whorl is probably a response to the contrast of light above and dark below. Many larvae fail to reach the whorl, and success is reduced by high winds and rain, and by some physical features of the plants. Two sorghum cultivars, IS 1151 and IS 2205, differed in the extent to which larvae successfully reached their whorls, and their relative susceptibilities altered with age.
Development of a monitoring trap for the olive fly, Dacus oleae (Gmelin) (Diptera: Tephritidae), using a component of its sex pheromone as lure
Authors: Jones O. T. , Lisk J. C. , Longhurst C. , Howse P. E. , Ramos P , Campos M. 
Published: July 2009

AbstractA major component of the sex pheromone of Dacus oleae (Gmel.) has recently been identified as a spiroacetal. The use of this compound as a lure for use in the development of a monitoring trap for that species is described. Polyethylene vials gave a slower release rate of the spiroacetal than rubber septa or microfibres, but even in polyethylene vials a loading in excess of 10 mg was required (optimum 20 to 25 mg) to obtain catches in delta traps which were comparable with those in unbaited vertical yellow sticky traps. In studies in an olive grove near Granada, Spain, a 25-mg spiroacetal lure used with a vertical yellow trap gave catches of males of D. oleae which were four times as great as those in delta traps with the same lure or in unbaited yellow traps. The height of the trap had no apparent effect on catch. Previously recorded components of the sex pheromone did not prove to be effective when combined with the spiroacetal. Combined monitoring of Prays oleae (Bern.) and D. oleae, using their respective pheromones in the same trap, appears to be feasible with delta traps.
The influence of host-plant on the development of the adult brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), and its significance in migration
Authors: Padgham D. E. 
Published: July 2009

AbstractThe development of adults of Nilaparvata lugens (Stål) reared on one susceptible and one resistant variety of rice plants of different ages was compared. Throughout the range of plants tested there was an overall trend for the newly moulted adult to synthesise and store a reserve of lipid and to lose most of the stored glycogen accumulated during the nymphal stage. N. lugens has two wing morphs, and whilst lipid deposits were greatest in the macropterous ‘migrant’ males, in females it was the brachypterous ‘reproductive’ insects that had the highest lipid deposits and also the greatest residual body weight. However, because of their lower body weight, the macropterous females had the greater percentage of lipid. Both flight willingness and the percentage of macropterous females showing flight-orientated physiological development increased with the age of the host-plant. Both survival and migration potential were lower in insects reared on the resistant rice variety compared to those reared on the susceptible variety. The pattern of post-flight resynthesis of fuels suggests that more than one major migration is unlikely.
The biology of Bubas bison (L.) (Coleoptera: Scarabaeidae) in southern France and its potential for recycling dung in Australia
Authors: Kirk A. A. 
Published: July 2009

AbstractThe biology of Bubas bison (L.) was studied in southern France. It was active from September to the end of May. Adult emergence lasted from September to January; 8 % of the female population was parous and laying eggs in September, and 100% were parous from February to the end of June. Females exhibited extraovariolar egg resorption, which may have been a response to adverse conditions. Eggs laid in October, November, February and March hatched synchronously in May. Adults resulting from eggs laid in March emerged in early September. The rate of oviposition varied from 0–03 egg/day in January to 0·5 in March. Females stopped laying eggs for three weeks in January. The structure of the nests formed from buried dung brood-masses was studied. Each brood-mass contained two eggs, one at each pole. About 12 brood-masses were formed under each dung pad in October 1981. The mean length of each mass was 96 mm and the dry weight 10–5 g. The mean number of masses in a nest was 24, with a mean number of 4–9 nests under each dung pad. The dry weight of dung buried under a pad in October 1981 was 1239 g, 66–6%, of the mean dry weight of an experimental dung pad. B. bison has the potential for recycling large amounts of dung in climatic areas of Australia equivalent to southern France.
Inheritance and activity of some esterases associated with organophosphate resistance in mosquitoes of the complex ofCulex pipiensL. (Diptera: Cnlicidae)
Authors: Villani F. , White G. B. , Curtis C. F. , Miles S. J. 
Published: July 2009

AbstractEighteen strains of the complex ofCulex pipiensL. from Africa, Asia and Europe were bioassayed for resistance to chlorpyrifos and electro-phoresed and stained for esterases. Susceptible strains showed only low activity esterase bands. The resistant strains ofC. quinquefasciatusSay from hot countries (Liberia, Nigeria, Sri Lanka, Tanzania, Thailand) all showed the same two high intensity esterase bands (Rm 0·60 + 0·82). Different patterns of high esterase were found in resistantC. pipiensstrains from cooler localities in Nairobi, Kenya (Rm 100), and Mont-pellier, France (Rm 0–50). Selection experiments on strains originally polymorphic for resistance and esterase pattern showed, without exception, that high esterase remained associated with resistance, and it is concluded that the association is almost certainly causal and not merely due to genetic linkage. The high intensity esterase bands were probably due to alleles of the loci Est-l, Est-2 and Est-3, separated by crossover distances of approximately 2·4 and 5·5 units, respectively. Strains monomorphic for what appeared to be the same high esterase pattern varied markedly in resistance level. Enzyme assays showed a direct relationship between levels of enzyme activity and resistance. Bioassays with fenthion and chlorpyrifos revealed differences in the relative resistance ofC. quinquefasciatusfrom Colombo (Sri Lanka) and Dar-es-Salaam (Tanzania). Despite these differential degrees of cross-effectiveness, it is concluded that high intensity esterases are reliable indicators of organophosphate resistance in mosquitoes of theC. pipienscomplex, although the possibility of other resistance mechanisms means that the lack of abnormally active esterases does not necessarily indicate the absence of resistance.
New species of Platygastridae (Hymenoptera) from India which parasitise pests of mango, particularly Procontarinia spp. (Diptera: Cecidomyiidae)
Authors: Austin A. D. 
Published: July 2009

AbstractFive new species of Platygastridae associated with mango pests in India are described. Synopeas procon sp. n., S. temporale sp. n., S. mangiferae sp. n. and Inostemma oculare sp. n. parasitise mango leaf gall midges, Procontarinia spp. (Cecidomyiidae), while Inostemma apsyllae sp. n. is associated with the psyllid Apsylla cistellata (Buckt.). Notes on a further two species, the platygastrid Trichacoides indicus Jackson and the ceraphronid Aphanogmus sp., associated with Procontarinia are given. A key to separate these parasites as well as comments on their biology and distribution are presented.
Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). III. Relationship between the level of resistance to pyrethroids, control failure in the field and the frequency of gene kdr
Authors: Farnham A. W. , O'dell Kate E. , Denholm I. , Sawicki R. M. 
Published: July 2009

AbstractTolerance of bioresmethrin, permethrin, deltamethrin and the natural pyrethrins with and without synergists (piperonyl butoxide and propyl prop-2-ynyl phenylphosphonate), and the frequency of kdr homozygotes (flies surviving a discriminating dose of DDT+FDMC (1,1-bis(4-chlorophenyl)-2,2,2-trifluoroethanol)) was investigated in 42 strains of Musca domestica L. collected on British pig farms and in one Canadian strain. Although all field strains were at least 4–10 times more tolerant of synthetic pyrethroids at the LD50 than the standard susceptible Cooper strain, and 27 strains (26 British + 1 Canadian) had detectable levels of kdr, pyrethroids failed to control flies on only nine farms where 10% of flies or more were homozygous for kdr and/or the LD50s (in μg/female) in bioassays equalled or exceeded 0·1 for bioresmethrin, 0·12 for permethrin, 0·012 for deltamethrin or 1·1 for pyrethrins. These figures correspond to resistance factors (Cooper strain = 1) of 20, 15, 30 and 4, respectively. Regression analyses showed a close relationship between the LD50s to pyrethroids and the frequency of kdr homozygotes. Cross-resistance to trichlorfon, which in part results in the 4–10-fold increased tolerance to pyrethroids observed in strains lacking kdr, was insufficient to cause control failure. The quantification of the relationship between the frequency of an insecticide-resistant genotype, levels of resistance as measured by bioassays and control failure in the field provides the means of forewarning when control failure is likely to occur and of confirming resistance as the cause when it has taken place.
Relative fitness of organophosphate-resistant and susceptible strains of Culex quinquefasciatus Say (Diptera: Culicidae)
Authors: Amin A. M. , White G. B. 
Published: July 2009

AbstractThe effects of chlorpyrifos resistance on fitness in Culex quinquefasciatus Say was evaluated in terms of life-span, fecundity, fertility and rate of development, and these parameters were integrated by calculating the intrinsic rate of natural increase. A chlorpyrifos-resistant strain from Tanzania had very significantly reduced biotic fitness compared to a standard susceptible strain, CfCA, from Sri Lanka. However, after five generations of backcrossing the resistant gene into the genetic background of the susceptible strain, fitness was found to be closer to that of the susceptible strain. The reduced fitness of the original Tanzanian strain therefore appears to be mainly due to background genetic factors rather than to the major resistance gene itself.
Studies in South America of arthropods on the Salvinia auriculata complex of floating ferns and their effects on S. molesta
Authors: Forno I. W. , Bourne A. S. 
Published: July 2009

AbstractInsects and mites associated with each species in the Salvinia auriculata complex were recorded in Trinidad, Venezuela, Guyana, Brazil, Uruguay, Paraguay and Argentina. There was a consistent pattern of herbivore-plant association throughout the range of the complex. Field studies showed that three insects, the curculionid Cyrtobagous sp., the pyralid Samea multiplicalis Gn. and the pauliniid Paulinia acuminata (Deg.), together contained Salvinia molesta at a density slightly below the carrying capacity of the environment in coastal areas of Brazil.
A field study of the predators of the grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae), in winter wheat in Britain
Authors: Holmes P. R. 
Published: July 2009

AbstractIn a field study of Sitobion avenae (F.) in winter wheat at Cranfield in southern England, the main predators were found to be the larvae of the staphylinid Tachyporus sp. and syrphids. Most predation occurred overnight. These predators were active during the period when the wheat crop was most suitable for aphid population increase, and in 1982 were apparently responsible for preventing an outbreak at Cranfield.
Winter mortality, development and reproduction in a field population of Myzus persicae (Sulzer) (Hemiptera: Aphididae) in England
Authors: Harrington R. , Xia-Nian Cheng 
Published: July 2009

AbstractPopulation change in Myzus persicae (Sulz.) overwintering on spring cabbage in south-eastern England was studied in relation to meteorological and biological factors. Leaf surface wetness and temperature were correlated significantly with rate of population change, but rainfall and wind were not. Growth and development continued slowly throughout the winter, and the relationship with temperature is shown. Hymenopterous parasites, the fungus Entomophthora and predatory spiders did not affect winter survival.
On the accuracy of age-grading neotropical Phlebotomines by counting follicular dilatations: first laboratory experiments, using colonies of Lutzomyia flaviscutellata (Mangabeira) and L. furcata (Mangabeira) (Diptera: Psychodidae)
Authors: Ready P. D. , Lainson R. , Wilkes T. J. , Killick-Kendrick R. 
Published: July 2009

Abstract‘Blind’ trials using laboratory-bred females that had completed 0–3 gonotrophic cycles showed that Polovodova's method of assessing parity, by noting the presence of follicular dilatations, is applicable to Lutzomyia flaviscutellata (Mangabeira) and L. furcata (Mangabeira). However, at the resolution of the techniques used, classification is limited to a simple division into nulliparous and parous flies. The presence of granules in the ovarian accessory glands was found to be an unreliable indicator of parity for both species.
Reduced fecundity ofPsoroptes ovis(Hering) (Acari: Psoroptidae) on calves treated with ivermectin
Authors: Guillot Frank S. , Wright Fred C. 
Published: July 2009

AbstractIvermectin injected subcutaneously into calves at the rate of 200 μ/kg body weight completely eliminated females ofPsoroptes ovis(Her.) in 22 days. Injection of ivermectin also adversely affected the number and hatch of eggs and the proportion of adult males forming attachment pairs. The reduced number of eggs recovered in skin scrapings was apparently the result of a significantly lower fecundity among females that temporarily survived on treated calves. Females that were exposed to ivermectin for only three days did not recover their full reproductive potential even though they were transferred to calves not injected with ivermectin. The proportion of ovigerous females among survivors was not significantly affected five days after injection. Since the number of eggs recovered in skin scrapings was substantially reduced after only three days, the effect of ivermectin on female fecundity was not primarily gonadal. Reduction in the number ofP. oviseggs three days after treatment probably occurred because of a combination of mortality of adult females and reduced oviposition by ovigerous females surviving in the population.
A new look at thrips (Thysanoptera) mouthparts, their action and effects of feeding on plant tissue
Authors: Chisholm I. F. , Lewis T. 
Published: July 2009

AbstractTo elucidate how thrips feed, the mouthparts of Limothrips cerealium (Hal.) were examined in dead specimens by scanning electron microscopy and plasma-ashing, and in living specimens by cinematography as individuals fed through a transparent membrane on clear liquid containing small polystyrene latex particles that made its flow visible. Close contact with the food substrate was maintained by the labral pad. The single mandible was used to pierce the membrane and was then withdrawn rapidly and replaced by the maxillary stylets, which formed a tube with either a terminal or sub-terminal opening into which food was drawn by cibarial pumping at 2–6 pulsations/s. Oscillations in the surrounding fluid caused by such pumping were detectable up to 58 μm from the maxillary opening. Feeding persisted from a few seconds to up to half an hour, and when complete the stylets were withdrawn either rapidly and together, or more gradually by sliding one against the other. Whole chloroplasts up to 6 μm in diameter were ingested even though the diameter of the maxillary tube was about 1 μm. The thrips consumed the contents of ruptured plant cells at about 8·5 × 1O-5 μl/min, equivalent to almost 12·5% of their body weight per hour. Probing and feeding removed the surface wax from leaves, and the cuticle was so exposed that it often wrinkled. Leaf cells beneath a pierced epidermal cell were usually emptied completely, and little seepage from the wounded tissue occurred after stylet withdrawal. After intensive feeding, many mesophyll cells were totally destroyed and others showed extreme plasmolysis; grana sacks were contorted and large starch grains formed due to desiccation. Above such internal damage the epidermal cells collapsed, and the outer cuticle wrinkled and appeared silvery before turning yellow and brown.
Wing fray inGlossina morsitans centralisMachado (Diptera: Glossinidae)
Authors: Allsopp R. 
Published: July 2009

AbstractA study of wing fray and ovarian age in females ofGlossina morsitans centralisMachado in Botswana confirmed that although the relationship between the two was strong it varied from month to month. The rate of wing fray with age was greatest in the hot dry season, and in both very young and very old females it was affected by humidity. Both age and activity are manifested as fraying of the wings, but it is considered unlikely that wing fray could be used as a reliable measure of either. It is suggested that wing fray may impose a physiological limitation on the lifespan of tsetse flies and may consequently be a factor in population regulation.
Circadian flight activity ofSimuliumspp. (Diptera: Simuliidae) sampled with a vehicle-mounted net in central Nigeria
Authors: Roberts D. M. , Irving-Bell R. J. 
Published: July 2009

AbstractA vehicle-mounted net was used to study the circadian flight activity of several species ofSimuliumin a northern Guinea savanna area in Nigeria during the dry season. The sampling method yielded large numbers of both sexes ofSimulium squamosum(Endertein) of the,S. damnosumTheobald complex,S. hargreavesiGibbins,S. voraxPomeroy,S. adersiPomeroy,S. hirsutumPomeroy and other species. The main peak of activity of all species recorded occurred just after sunset and there was a smaller peak just before sunrise. Flies continued to be caught at a low level 2·5 h after sunset when sampling ceased. Differences in the activity patterns ofS. squamosummales and females and of the other species were analysed. Of theS. squamosumfemales caught, 12% were blood-fed; these and gravid females were mainly active in the evening, while the blood-thirsty flies had a high level of activity throughout the day. Differences between species in the relative activity of blood-thirsty and gravid flies, and nulliparous and parous flies are noted.
The effect of larval rearing conditions on flight performance in females of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae)
Authors: Parker W. E. , Gatehouse A. G. 
Published: July 2009

AbstractThe effect of quantitative and qualitative differences in maize leaf fed to larvae of Spodoptera exempta (Walker), and of larval density, on flight duration in female moths was investigated using a tethered-flight technique. Neither food deprivation nor diets of water-stressed maize influenced the proportion of moths flying for long periods. However, a significant increase in the incidence of long flights was recorded in moths from larvae reared at high densities. Significant differences were observed in the weights and sizes of moths from the different larval treatments. Wing-loading was shown to be a function of moth weight, with lighter moths having lower wing-loadings. However, wing-loadings of long-flying moths and those of short-fliers were similar, and it is concluded that the migratory potential of females of S. exempta cannot be predicted from moth weight or morphometric data. A feature of the results was the variable proportion of long-flying moths in the test and control groups, irrespective of larval treatment. Re-examination of the data showed that a high incidence of long flights was evident in the experimental insects at approximately one-generation intervals, and it is suggested that there is a major genetic component in the determination of flight capacity in this species.
Interpretation of the flight activity of Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Hemiptera: Delphacidae) based on comparative trap catches and field marking with rubidium
Authors: Perfect T. J. , Cook A. G. , Padgham D. E. , Crisostomo J. M. 
Published: July 2009

AbstractDetailed studies were conducted over a five-year period at a rice farm in the Philippines on the flight activity of Nilaparvata lugens Stål) and Sogatella furcifera (Horváth). Suction traps were used to measure aerial density, and catches included immigrants, emigrants and insects undertaking trivial flight. Activity was partitioned using a variety of other trap types. Emigration was effectively monitored using net canopy traps and immigration was best measured using green water traps. Yellow water traps also measured immigration, but when macropterous adults were being produced within the plot, insects undertaking trivial flight were also caught. The light-trap caught immigrant and over-flying migrant insects.