bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sex ratio and adult behaviour of the Antarctic midge Belgica antarctica (Diptera, Chironomklae)
Authors: EDWARDS JOHN S. , BAUST JOHN 
Published: March 2008

Abstract. 1. The sex ratio in populations of the Antarctic chironomid Belgica antarctica approximates 1:1 at eclosion.2. Male predominance in surface populations of the short‐lived adult persists throughout the summer. The mean ratio, based on data from surface aggregations (austral summer 1977–78) and from sticky traps (1978–79) is about 6:1, with a steady seasonal decline from 10–20:1 to 2–5:1.3. Males live slightly longer than females but the difference does not account for observed ratios.4. Samples of adult populations taken from subsurface sites have sex ratios nearer to equality than surface populations.5. It is concluded that the male‐dominated surface populations are equivalent to the male swarms typical of winged Chironomidae.6. Capture of airborne adults shows that aerial transport as well as water‐surface rafting may play a role in dispersal of adults.
The influence of age and season on dispersal and recapture of Anopheles culicifacies in Sri Lanka
Authors: RAWLINGS P. , CURTIS C. F. , WICKRAMASINGHE M. B. , LINES J. 
Published: March 2008

Abstract. 1. Three mark—release—recapture experiments with Anopheles culicifacies were carried out at different seasons in Sri Lanka. Blood fed females were collected daily in cattle baited huts, marked with fluorescent powder and released in the same village. In two of the experiments males and females were reared, marked when newly emerged, and released. The recapture rates were recorded in the same village and in a second village 2 km away.2. The mosquitoes marked when already mature yielded an estimate that 2–7% of the mosquitoes in the second village had flown from the first. The recapture rate of reared mosquitoes in the first village was much lower than with those marked when already mature. This difference could be at least partly attributed to a tendency to disperse when young, as shown by the considerable number of recaptures of young mosquitoes in the second village.3. By varying the colour used for marking, estimates were made of the amount of dispersal from hut to hut in the first village, the daily survival rate and the proportion of the wild population resting in the collecting huts each day.4. Using the latter two estimates equations have been solved predicting the rate of build‐up of the proportion of recaptures. These predictions were compared with the observed results. The data on dispersal are discussed in relation to possible method for delaying the build‐up of insecticide resistance.
Plant tannins and insect herbivores: an appraisal
Authors: BERNAYS E. A. 
Published: March 2008

Abstract. 1. The bioassays with tannins and insects, and the ecological studies on insects implicating tannins, are summarized and discussed.2. Because of the great variation now shown in all aspects of the insect‐tannin relationship, the difficulty of making generalizations is stressed.3. The significance of plant tannins for insect herbivores is reconsidered in the light of recent work and little‐known older work, which illustrate the very varied nature of its effects.
The nesting biology and population dynamics of the Seychelles potter wasp Eumenes alluaudi Perez
Authors: BROOKE M. DE L. 
Published: March 2008

Abstract. 1. The nesting biology of the solitary potter wasp Eumenes alluaudi was studied on Cousin Island, Seychelles.2. Although the rainy season was from October to April there was no indication of strong seasonality in the wasps' nesting.3. Females tended to nest close to where other females were nesting.4. The mean number of cells per nest was 3.71, the mean number of nests made per female 135, and the percentage of cells from which adults emerged 65.87; thus the mean number of adult wasps emerging from the nest(s) of each breeding female was 3.29.5. Male‐producing eggs were laid before female‐producing eggs and the estimated sex ratio at emergence was, at 1:2.52, female biassed. It is possible that inbreeding occurred.6. Daily mortality of nesting females was estimated as 0.088.7. The mean interval between a female's emergence and her starting to nest was 19.7 days.8. Marking showed that only 26.7 ± 6.3% of females emerging from cells in the study area returned to breed there. Since the number of emerging daughters per breeding female was only 5.01 times 0.66 times 0.72 = 2.36 (fecundity x proportion emerging x proportion of females emerging), the number of returning females would be only 236 times 0.267 = 0.63, and hence, in order to maintain numbers over many generations, 037 females must have been immigrants.
Abundance and survival of a seed‐infesting weevil, Pseudanthonomus hamamelidis (Coleoptera: Curculionidae), on its variable‐fruiting host plant, witch‐hazel (Hamamelis virginiana)
Authors: STEVEN DIANE DE 
Published: March 2008

Abstract. 1. The relative importance of seed abundance and of mortality factors in the population biology of Pseudanthonomus hamamelidis, a hostspecific predispersal seed predator on Hamamelis virginiana, is evaluated by analysis of weevil life tables and abundance estimates in three years with markedly different magnitudes of fruit production.2. Fruit production of marked Hamamelis individuals averaged 336 m‐2 in 1978, increased three‐ to four‐fold in 1979, and declined again in 1980. More individuals fruited in 1979 than in the other two years.3. The early larval stage of P.hamamelidis incurred the greatest mortality, with 42–58% dying from often undeterminable causes. Losses in the egg stage ranged from 22% to 31%. Three parasitoid species each accounted for minor mortality. Generation survival was similar in all three years, ranging from 21% to 28%.4. The percentage of Hamamelis fruit crops infested by P.hamamelidis was high in 1978, averaging 76%, but was much lower in 1979, the year of abundant fruit. In 1980, when fruit were less abundant again, infestation was nearly complete. Egg densities on fruits were lower in 1979 than in the other two years.5. The fluctuating fruit crops of Hamamelis are responsible for limitation of P.hamamelidis numbers during poor fruiting years. The occasional highly productive fruiting year results in satiation of weevil populations and concomitant seed escape by Hamamelis. Mortality factors appear less important in influencing weevil population dynamics.
Relation of oxygen consumption to size and temperature in desert arthropods
Authors: MISPAGEL MICHAEL E. 
Published: March 2008

Abstract. 1. Oxygen consumption was determined for ninety‐three taxa of desert‐inhabiting arthropods of various life stages over the temperature range 10–40d̀C. Regression analysis of O2 consumed/individual/h on the mean dry weight of individual adult insects yielded a slope of 0.70 (r= 0.87) while the same analysis for non‐insect arthropods gave a slope of 0.74 (r ‐ 0.87).2. Average Q10 for all insects was 2.16 ± 0.66 over the 10–40d̀C temperature range. Q10was not significantly different among orders of arthropods at each 10d̀ temperature interval but decreased significantly with an increase in temperature.3. Per cent water content ranged from a mean of 60% for Coleoptera to 78% for Lepidoptera larvae and indicated the necessity of using dry weight values in analyses of the relationship between size and oxygen consumption rates.4. Models are supplied for each taxon to calculate the minimum energy for basic metabolism of field populations per unit time and area.
Successful and unsuccessful development of colonies ofVespula vulgaris(Linn.) (Hymenoptera: Vespidae)
Authors: ARCHER MICHAEL E. 
Published: March 2008

Abstract.Six categories of immature and five categories of mature colonies are described and their developmental relationships suggested.Mature brood destroyed by the workers became numerous in 46.4% of the immature colonies. Most of these formed unsuccessful colonies (36.9%) producing few or no queens. The remaining 9.5% recovered to form successful colonies.Successful colonies either reared queens only (mean 356 queens), or queens (mean 1461) and males (mean 254) in their large cells.The number of small cells in mature colonies correlated with the number of cells built by the founder queen.The greater the number of large cells in a mature colony the greater were the chances that a larger proportion of these cells would be used to rear adults.The number of small and large cells are correlated in mature successful colonies.Queen activity and quality are important factors in the control of colony size and success.Selective destruction of male sealed brood in the large cells is linked to worker, rather than queen, control.
Patterns of herbivory on Passiflora leaf tissues and species by generalized and specialized feeding insects
Authors: DENNO ROBERT F. , DONNELLY MAUREEN A. 
Published: March 2008

Abstract.

The feeding patterns of specialized (Heliconius butterflies) and generalized (the grasshopper, Osmilia flavolineata) herbivores on leaf age classes and species of neotropical vines in the genus Passiflora are compared by offering them leaf discs in choice experiments.
Heliconius larvae selected young meristematic leaves over medium aged and mature leaves of Passiflora auriculata on which to feed.
Adults of O. flavolineata consumed more young leaves of P. pittieri from an array of different ages of leaf tissue, but showed no preference for young over mature leaves of P. tetrastylus or P. data.
In choice tests conducted with medium aged leaves of four species of Passiflora, O. flavolineata selected P. tetrastylus over P. pittieri and P. vitifolia, which were consumed more than P. alata.
P. alata, which was avoided by O. flavolineata in feeding trials, was the only abundant Passiflora in neotropical habitats where generalized herbivores (grasshoppers and katydids) were common.
Our results suggest that Passiflora species in forest habitats where some generalized herbivores are rare have fewer chemical defences, but retain physical defences (tough leaves and hooked trichomes) rendering them unpalatable to specialized herbivores like the larvae of Heliconius butterflies.
The feeding behaviour of two leafhoppers on Vicia faba
Authors: GÜNTHARDT M. S. , WANNER H. 
Published: March 2008

Abstract.

The feeding behaviour of the two Typhlocybinae Empoasca decipiens Paoli and Eupteryx atropunctata Goetze and the nature of the damage caused to Vicia faba L. were investigated.
Sections with stylets in situ, i.e. within the plant, were obtained. Eupteryx atropunctata sucked mainly from the palisade parenchyma of the leaf, while several generations of Empoasca decipiens could also live from the stem parenchyma and pierced into phloem if this was reachable.
Acoustic competition in bush crickets
Authors: LATIMER W. 
Published: March 2008

Abstract.

The bush crickets Platycleis albopunctata (Goeze) and Metriop‐tera roeselii (Hagenbach) interact acoustically in the laboratory. The interaction is principally one‐way, resulting in modification of the song pattern of P. albopunctata or its inhibition. Similarity of the frequency spectra of songs of both species is one of the principal reasons for reactivity.
Nymphal male P. albopunctata individuals are randomly distributed in dense Brachypodium pinnatum L. grasslands. Adult males become regularly spaced with the onset of singing activity. Acoustic behaviour is the most likely mechanism maintaining regular spacing within the male P.albopunctata population.
In many localities juvenile P. albopunctata and M. roeselii are sympatric, occurring together in the same vegetation.
With the onset of singing activity by the adult males the two species separate though there is no detectable difference in habitat preference.
The separation is effected by a negative phonotactic response by P. albopunctata to the song of M. roeselii. It is suggested that this response is derived from behaviour patterns that result in ‘territorial’ spacing within the P. albopunctata (male) population.
This behaviour prevents the occurrence of song modification in the field but also excludes P. albopunctata from areas of suitable habitat where the population density of M. roeselii is high.
Population fluctuations of mosquitoes in the non‐seasonal tropics
Authors: WOLDA HENK , GALINDO PEDRO 
Published: March 2008

Abstract.

Seasonal and annual fluctuations in abundance of a number of species of mosquitoes were studied in a relatively non‐seasonal climate near Almirante, Panama.
The fluctuations observed were large, but did not have a period of 1 year and should be classified as non‐seasonal.
At each site the various species were not synchronous in their fluctuation pattern, but the fluctuations of each species were synchronous over an area of at least 4 km long, in spite of large differences in habitat.
Changes in abundance from year to year observed in these mosquitoes are large compared with those of insects, including mosquitoes, in other areas of Panama.
The importance of such large and unpredictable fluctuations in abundance for planning control measures is discussed.
Insect herbivore guilds and species—area relationships: leafminers on British trees
Authors: CLARIDGE M. F. , WILSON M. R. 
Published: March 2008

Abstract. 1. 239 species of leafmining insects have been recorded from thirty‐seven species of trees and large shrubs in Britain.2. A significant species—area relationship was obtained for these insects, but it explained only 19% of the variation about the regression he. A further 23% of the variation may be accounted for by taxonomic relationship of host plants.3. A significant correlation was established between the number of species of leafminers and those of mesophyll‐feeding leafhoppers for twentyeight host tree species. Both guilds are dominated by host specific feeders.4. It is suggested that species—area effects are important in determining species richness of phytophagous insects mainly when groups of closely related host plants are considered. With more diverse arrays of hosts, taxonomic influences, which are probably mainly chemical, may outweigh such area related effects.
The distribution and biology of Lonchopteridae (Diptera) in upland regions of northern England
Authors: COULSON J. C. , BUTTERFIELD JENNIFER 
Published: March 2008

Abstract. 1. A survey was made of the distribution of Lonchopteridae over 2 years at forty sites in northern England. Material was collected by pitfall trapping.2. Two species, Lonchoptera lutea and L.furcata, were taken in approximately similar numbers. No other species were recorded.3. Considerable separation of the two species was found, with both species occurring at ten sites, whilst one species only was taken at twenty‐five sites. L.furcata occurred coinrnonly on upland mineral sods, shallow peat soils and on lowland bogs whilst L.lutea was numerically most abundant on upland blanket bog.4. Almost 39% of the L.lutea specimens and 14% of the L.furcata captures were males.5. The capture of numbers of males of L.furcata is unusual, since the species is regarded as being parthenogenetic and males occur only in a very small part of the species' range. Confirmation of the association between the males and females of L.furcata is given, whilst there is close agreement between the cliaetotaxy of British males and females, and British and continental European females. The suggestion that the males belong to an undescribed species is rejected.6. The seasonal capture of L.lutea adults is similar at all altitudes. Captures of males of L.furcata show an abrupt seasonal change above and below about 420 m; captures being in mid‐summer in the higher altitude zone and between October and December at lower altitudes. The captures of females of L.furcata show the same trend, but this is partially obscured by the longer life‐span of the females. It is suggested that this difference represents a change in the lifecycle, possibly from an annual to a biannual one at the higher altitudes.7. The biology and distribution of the Lonchopteridae at low altitudes requires investigation.
Intraspecific competition amongst larval Aedes aegypti: food exploitation or chemical interference?
Authors: DYE CHRISTOPHER 
Published: March 2008

Abstract. 1. Competition within and between the larval instars of the yellow fever mosquito, Aedes aegypti, can be measured by its effect on stage duration. In a series of laboratory experiments the relative importance of chemical interference and food exploitation in mediating competition between first and fourth instar larvae was investigated.2. In contrast to the results of three previous studies, I found no evidence that a chemical growth retardant played any part in greatly prolonging the stage durations of larvae in both age classes.3. When competition between the two age classes became important, the relative increase in stage duration wasgreater for first instar larvae than for fourth instar larvae. This result can be reproduced with Gilpin & McClelland's (1979) model of competition by food exploitation alone, providing the range of available food particle size is assumed to be an increasing function of age. An additional, but less important, refinement makes the conversion efficiency of food into larval biomass a decreasing function of age.
Entomogenous fungi in tropical forest ecosystems: an appraisal
Authors: EVANS H. C. 
Published: March 2008

Abstract. 1. Species of the genus Cordyceps (Ascomycotina; Clavicipitales) are the commonest fungi encountered on arthropods in tropical forests.2. The asexual states of Cordyceps may occur in conjunction with or separately from the perfect state and are classified in the genera Hirsutella, Hymenostilbe, Nomuraea, Paecilomyces and Verticillium of the imperfect fungi (Deuteromycotina; Moniliales).3. Most Cordyceps species have a restricted host range and this rigid host specificity, at the generic or tribal level, is especially evident in ant‐fungal associations.4. Pathogenicity was not tested but circumstantial evidence is presented which supports the view that Cordyceps species are primary pathogens of arthropods.5. Observations of living, infected ants suggest that behavioural patterns are radically altered, possibly altruistically orientated.6. It is thought that entomogenous fungi are involved in the regulation of arthropod populations and may help to maintain stability in tropical forest ecosystems.7. The value of these organisms to man may be in the metabolites they produce rather than in their direct usage as biological control agents of insect pests.
Interspecific competition between two field populations of grass‐feeding bugs
Authors: GIBSON CHARLIE , VISSER MAYKE 
Published: March 2008

Abstract. 1. We tested the hypothesis that interspecific competition between two grass‐feeding stenodemine bug species (Notostira elongata Geoffroy and Megaloceraeu recticornis Geoffroy) was capable of causing population‐scale mortality in the field. 2. N.elongata nymphs were added to two field enclosures in which the M.recti‐cornis population was to hatch. In one of these enclosures the grass Arrhena‐therum elatius L., on which only M.recticornis can feed, was also added. Population changes of the bug species were then monitored. An unmanipulated enclosure and an unfenced plot of grassland were used as controls.3. The results demonstrated that N.elongata lowered the survival of M.recticornis and that this effect was removed by the addition ofA.elatius. The results also suggested that N.elongata suffered less from the effects of competition with M.recticornis when the latter had access to the refuge foodplant.4. Interspecific competition was rare among members of the grass‐feeding stenodemine guild in the area studied. Only one out of fifteen possible pairs competed, and this competition occurred only under special circumstances.
Normal and atypical nesting behaviour of Copris lunaris (L.): comparison with related species (Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G. 
Published: March 2008

Abstract. 1. The lifecycle, mating and larval behaviour of Clunaris are described. Adults appeared in the autumn and nested in the following spring. The female beetle remained in the nest with the brood and could nest again the following year.2. Nesting was initiated when virgin females were mated in the spring. Brood balls were formed by techniques sirnilar to those used by Scarabaeini. The female beetle left the nest soon after the first imagos broke out of the brood balls.3. Nesting behaviour was readily modified by external conditions. Many parts of the sequence could be repeated or omitted. The female beetle left the nest if the brood was removed, but she remained for longer than usual if younger brood was substituted near the end of the normal nesting period.4. Certain experimental conditions released behaviour patterns typical of other species. These were formation of superficial nests or of two‐chambered nests, oviposition before completing the brood ball, and coating of the brood balls with soil (all found in other Coprina), as well as ball rolling and ball burial (found in Scarabaeini). The results are discussed in relation to the evolution of Copris nesting behaviour.
Oviposition behaviour of the grasshopper Zonocerus variegatus
Authors: McCAFFERY A. R. , PAGE W. W. 
Published: March 2008

Abstract. 1. Long‐term changes in the numbers of Zonocerus at oviposition sites reflect changes in the maturity of the general population.2. Short‐term changes in the numbers of Zonocerus at oviposition sites are associated partly with normal diurnal behaviour in which roosting occurs at night.3. Immigration of Zonucems, particularly females, into the oviposition site occurs prior to periods of oviposition activity. Emigration follows oviposition.4. The majority of Zonocerus move upwind into the oviposition site suggesting an odour and/or sound attraction.5. Periods of intense oviposition activity follow heavy rainfall.
Instar duration, adult consumption, oviposition and nitrogen utilization efficiencies of leafhoppers feeding on different quality food (Auchenorrhyncha: Homoptera)
Authors: PRESTIDGE R. A. 
Published: March 2008

Abstract. 1. Plant material of Holcus lanatus L. removed from an artificially fertilized trial was used to rear leafhoppers of three feeding types: Dicrano‐tropis hamata Boheman and Ebmana sulphurella Zetterstedt, (phloem feeders), Eucelis incisus Kirschbaum (xylem feeder) and Zyginidia scutellaris Herrich‐Schaeffer (mesophyll feeder).2. In the laboratory, leafhopper instar durations, adult consumption rate, oviposition rate, and nitrogen utilization efficiency were influenced by the quality of the food consumed. Adult longevity was unaffected by the level of food quality normally found in plants.3. Z.scutellanis consumed mesophyll contents equivalent to 72% of its body weight each day but only digested about 30% of its intake. Eincicus had a low dry weight consumption rate (12% body weight/day) but digested its food more efficiently (60%) than the other feeding types. The two phloem feeders consumed mounts equivalent to 25% of their body weight each day and digested 40–50% of their intake.4. Each species reached maximum nitrogen utilization efficiencies at different plant nitrogen levels. This suggests that leafhopper species may be associated with a particular nitrogen concentration in the grasses.