bluuebunny/crossref_metadata_2025_split huggingface dataset:
Indicators of children's development: considerations when constructing a set of national Child Health Indicators for the European Union
Authors: Köhler L. , Rigby M. 
Published: November 2003

AbstractBackground  In a recent project, commissioned by the European Union, a set of Child Health Indicators were identified and recommended for use in all Member States. In that work, by a group of European experts, children's development was one of the key areas that were reviewed to clarify its role in this set of indicators. This paper deals with neurological (in a broad sense), social and moral aspects of development; other aspects, such as nutrition and physical growth, mental health, quality of life were dealt with in other areas.Methods  A number of methods are used to monitor children's neurodevelopment, to identify early deviations that could be treated or alleviated. Few tests fulfil basic criteria of screening and quality of evidence. For Child Health Programmes, developmental surveillance is instead recommended. As a proxy to social development, as part of children's process of adaptation into society, education indicators are recommended, such as suggested by OECD and UNICEF. Moral development is discarded as an indicator, because norms and values vary too much between countries.Conclusion  For now the Child Health Indicators of Life and Development Project found no ground to recommend any particular method or combination of methods for a general monitoring of children's neurological, intellectual, language and moral development, and for including the results as national indicators of children's health and well‐being in EU. For social development, indicators in the educational area seem most promising, as they have been proposed and used by OECD and UNESCO. In an ambitious monitoring programme, these indicators could be included as determinants of children's health and development.
Annual growth rates in newly established populations of the butterfly Pararge aegeria
Authors: POLLARD E. , ROTHERY P. , YATES T.J. 
Published: November 2003

1. The likelihood of range changes in the event of climate change makes study of the foundation and establishment of populations of particular relevance and interest.2. The butterfly Pararge aegeria has expanded its range in Britain over many decades. Since 1985, ten monitored sites in eastern England have been colonized and the pattern of population growth examined.3. Geometric annual growth rates in the establishing populations were initially, on average, three‐ to fourfold but subsequently declined. The decline provides possible evidence that density‐dependence limits final population densities, but other explanations are possible.
Temperature‐related fluctuations in the timing of emergence and pupation of Windermere alder‐flies over 30 years
Authors: ELLIOTT J. M. 
Published: November 2003

Abstract.

From 1966 to 1995, dates were recorded when adult alder‐flies, Sialis lutaria L., were first seen (30‐year range: 23 April − 25 May), 50% of the maximum density occurred (4 May − 4 June), and maximum density occurred (11 May − 17 June) along 200 m of Windermere shore. These emergence dates occurred at similar temperatures, estimated by mean values for both the emergence date and the week prior to emergence. The latter was the least variable at 10.1 °C (95% CL ± 0.37) for start of emergence, 11.2 °C (± 0.49) for 50% maximum density, 14.2 °C (± 0.51) for maximum density.
Final‐instar larvae pupated in damp soil just above the water line. As laboratory temperatures were increased slowly from an initial 5 °C, the cumulative number of larvae leaving the water to pupate increased. A quadratic equation described this relationship from a threshold temperature of 7.2 °C to completion at 14.0 °C (50% point, 9.3 °C). The relationship between successful pupations and constant temperatures in the laboratory was well described by a quadratic equation with an optimum 14.9 °C (over 90% success) and no success outside the range 7–23 °C. A negative power‐function described the relationship between days required for pupation and temperature, ranging from c. 28 days at 8.2 °C to c. 4 days at 22.1 °C.
Dates for larvae leaving the lake to pupate were back‐calculated from dates for adult emergence, using the power‐function for pupation time. Mean temperatures for estimated dates on which larvae left the lake to pupate were less variable than those for adult emergence, being 7.5 °C (± 0.20) for the start of pupation, 9.4 °C (± 0.16) for 50% maximum density, 13.7 °C (± 0.16) for maximum density. These values are similar to those obtained in the laboratory and can be used to predict pupation and adult emergence for different temperature regimes.
Male size and survival: the effects of male combat and bird predation in Dawson’s burrowing bees, Amegilladawsoni
Authors: ALCOCK JOHN 
Published: November 2003

1. Males of Dawson’s burrowing bee, Amegilla dawsoni, occur in two size classes, large majors and small minors. Major males compete aggressively for emerging females in completely exposed emergence areas, whereas minors often employ an alternative mating tactic, which involves rapid patrolling in the vegetated periphery of emergence areas.2. Because major males wrestle violently with rivals on the ground, they experience greater wing wear and a higher risk of wing damage than minor males. In addition, males patrolling emergence areas and waiting on the ground for emerging females are more likely to be killed by predatory birds than are peripheral minors.3. Measurements of longevity based on mark–recapture data suggest that majors are slightly shorter‐lived than minor males. If male–male combat and predators do reduce the lifespan of major males relative to minors, the effect would be to decrease the lifetime mating advantage of majors relative to minors.4. Differential mortality could therefore be a factor in the maintenance of the two forms of males in this species.
Colonization of host patches following long‐distance dispersal by a goldenrod beetle, Trirhabda virgata
Authors: HERZIG ROOT ANN, L. 
Published: November 2003

1. The arrival of the chrysomelid beetle Trirhabda virgata on isolated patches of its host Solidago altissima was closely monitored to determine how conspecific density and host condition influence colonization.2. Experimental host patches, which were set on the roof of a four‐storey building located 0.7 km from the nearest naturally occurring hosts, were frequently colonized by beetles over a 2‐week dispersal period.3. Females preferred lush host patches that were free from simulated Trirhabda chewing damage. Females colonized lush patches more often than defoliated patches at two spatial scales, when patches were 2 m and 25 m apart. Males did not show a strong preference for lush plants.4. Males aggregated on plants that already contained adult conspecifics, apparently increasing their reproductive success. Females did not respond to the presence of adults on the patch.5. Ninety‐five per cent of the females arriving on the isolated plants had mated before flying, indicating that lone females are able to colonize empty stands.6. By avoiding heavily defoliated plants, females should dissipate local outbreaks and spread their offspring away from over‐exploited areas.
Influence of larvae of Gastrophysa viridula on the distribution of conspecific adults in the field
Authors: SCHINDEK RALF , HILKER MONIKA 
Published: November 2003

1. Previous laboratory bioassays indicate that exocrine glandular secretions of larvae of Gastrophysaviridula repel conspecific adults and deter them from feeding and oviposition. The present study was conducted to investigate the influence of larvae of G. viridula on conspecific adults in the field.2. Within the G. viridula population studied, two generations were observed in a year. Occurrence of the different developmental stages overlapped temporally.3. Some individual plants of Rumex obtusifolius, the host of the G. viridula population studied, grew so close to each other that they were considered as a plant group. When investigating the spatial distribution of larvae and adults within such plant groups, larvae were rarely found on plant groups on which adults were feeding.4. A field experiment revealed that adults avoided plants of R. obtusifolius infested by conspecific larvae of the second and third instar. Adults still avoided these damaged plants when larvae had left them for pupation.5. Gastrophysaviridula avoided oviposition on leaves and plants infested by conspecific larvae. Larvae of the second instar significantly deterred oviposition when present at a high density (33.3 larvae/dm2), whereas larvae of the first instar did not deter oviposition of conspecifics at either density tested. The oviposition deterring effect was also observed when just exocrine glandular secretion of larvae of the second instar was applied to the leaves in amounts equivalent to a density of 33.3 larvae/dm2.6. Availability of food (R. obtusifolius) largely exceeded its exploitation in each group of plants examined. This may be due to either the spatial separation of adults and larvae or the low population density observed on these plant groups.
Increased fecundity, as a function of multiple mating, in an arctiid moth, Utetheisa ornatrix
Authors: LAMUNYON CRAIG 
Published: November 2003

1. Female Utetheisa ornatrix mate multiply and may receive up to thirteen spermatophores. Spermatophores provide the female not only with sperm but also with a nuptial gift of pyrrolizidine alkaloid that she transmits to the eggs, protecting them against predation. Thus, through multiple mating the female accrues nuptial gifts that add to the defence of her offspring.2. Multiple mating in female U. ornatrix brings about increases in fecundity, but not in longevity or egg mass. These increases occur through the third mating; the fourth and fifth matings, however, have no additional effect on fecundity.3. These results, taken with the fact that spermatophores are sizeable and are digested within the female, suggest that they bear nutritive gifts that the female uses in egg construction. Multiple mating thus allows females to accrue the resources to build additional eggs.4. These results are discussed in relation to the potential benefits accruing to donating such gifts and to male and female mating strategies.
Progressive restriction of host plant exploitation along a climatic gradient: the willow psyllid Cacopsylla groenlandica in Greenland
Authors: HODKINSON IAN 
Published: November 2003

1. Host plant selection by the endemic willow psyllid Cacopsylla groenlandica was studied at eight sites in three locations along a N–S climatic gradient in west Greenland.2. C. groenlandica oviposited and developed on four willow species: Salix glauca, S. arctophila, S. uva‐ursi and S. herbacea. Development took place on female catkins of all species and on leaf shoots of S. glauca.3. At sites in southern Greenland, C. groenlandica fully utilized all four willow species. However, there was progressive reduction of host plant species and tissues exploited as latitude increased, such that towards the northern limit of its range the psyllid became highly specialized, feeding only on female catkins of S. glauca, despite the presence of alternative hosts. Where plant growth was tightly constrained within a restricted growing season, the demands of synchronizing with more than one species may have become too great, resulting in specialization on a single host.4. The probable mechanisms producing specialization were between‐species differences in host plant phenology, linked to variation in the growing season, set against the partially non‐overlapping geographical distribution patterns of the host willows.5. A small degree of phenological asynchrony between host plants can be advantageous for the insect. Under favourable conditions the reproductive season can be extended by using a series of host plants with staggered phenologies. Some ‘early’ hosts also create predator‐free space. However, as asynchrony increases, the advantages disappear as the insect becomes unable to exploit the full range of host options.6. The importance of host plant synchrony in the life histories of arctic insects is discussed.
Effects of temperature and season on egg size, hatchling size and adult size in Notiophilus biguttatus
Authors: ERNSTING G. , ISAAKS J.A. 
Published: November 2003

1. Temperature‐induced egg size variation and its effects on successive life stages in the carabid beetle Notiophilus biguttatus were examined.2. In the laboratory, across temperature regimes, egg size and number were inversely related; number of eggs and total egg mass were higher, but egg size was smaller at high temperatures.3. Food intake rate was shown not to be involved in the temperature effect on egg size.4. Within the higher temperature regimes, among females, egg size was negatively correlated with number of eggs and with total egg mass.5. Data on egg mortality and egg development time did not explain why at low temperature eggs were larger than at high temperature.6. Larvae hatching from eggs produced at a low temperature were heavier than larvae from eggs produced at a high temperature, irrespective of temperature during development.7. In a prolonged outdoor experiment (January – July), encompassing the main breeding period of N. biguttatus, egg size decreased and both egg production rate and total egg mass increased in the course of the experiment.8. In the field, an effect of seasonal change in temperature on adult body size was found; teneral beetles that had their juvenile period early in the season were larger than those that had their juvenile period later in the season.9. The results of the study suggest a mechanistic explanation in which the egg size response to temperature follows from a difference in temperature sensitivity between two processes in oogenesis; adaptiveness of the temperature response was not clarified.
Persistent, localized outbreaks in the western tussock moth Orgyia vetusta: the roles of resource quality, predation and poor dispersal
Authors: HARRISON SUSAN 
Published: November 2003

1. On stands of the abundant perennial lupins Lupinus arboreus and L. chamissonis on the California coast, the western tussock moth Orgyia vetusta Bdv. occurs as only a few localized populations, which are locally dense enough to defoliate the host plants and yet do not appear to spread.2. To determine what limits the spatial distribution of this insect, and therefore its global abundance, experiments were performed at three sites, examining the roles of host‐plant quality, predator abundance, rates of predation and dispersal.3. At no site did host quality, predator abundance or rates of predation vary spatially in a way that would explain the location of the outbreak. However, adult female tussock moths are flightless, and rates of long‐distance aerial dispersal (‘ballooning’) by first‐instar larvae were very low at all sites. Poor dispersal is the only consistent explanation for the limited distribution of the tussock moth.
The Pieris napi /bryoniae hybrid zone at Pont de Nant, Switzerland: broad overlap in the range of suitable host plants
Authors: PORTER ADAM 
Published: November 2003

1. The butterflies Pieris napi and Pieris bryoniae hybridize in a narrow zone at ≈ 1200 m in the Alps and Carpathians of Europe. They feed as larvae on a variety of hosts in the Brassicaceae, and few host species occur on both sides of the hybrid zone.2. Females were captured on either side of the hybrid zone at Pont de Nant, Switzerland, eggs obtained, and larvae were offered plants from nineteen species of Brassicaceae and Reseda lutea (Resedaceae).3. Nine of the hosts were found to have eggs or larvae already on them. Only Capsella bursa‐pastoris and R. lutea were unsuitable.4. Significant survivorship differences among suitable hosts were found. There was no interaction between butterfly species and host plant, which would indicate adaptation by these taxa to their respective suites of hosts.5. Among suitable hosts, larvae of both taxa had higher mortality on plants with hairy leaves and on older plants beginning to senesce.6. Differential selection on host use, if it occurs at all, is likely to be a very minor factor in the dynamics of the Pieris napi/bryoniae hybrid zone.
Nitrogen and carbon isotope ratios in termites: an indicator of trophic habit along the gradient from wood‐feeding to soil‐feeding
Authors: TAYASU I. , ABE T. , EGGLETON P. , BIGNELL D. E. 
Published: November 2003

1. Nitrogen and carbon stable‐isotope ratios (δ15N and δ13C) of body tissues, mound/nest materials and dietary substrates were determined in termite species with differing trophic habits, sampled from the Mbalmayo Forest Reserve, southern Cameroon.2. δ15N of termite tissues was enriched gradually along a spectrum of species representing a trophic gradient from wood‐ to soil‐feeding. Species that could be identified from their general biology and from gut content analysis as feeding on well‐rotted wood or as wood/soil interface feeders showed δ15N intermediate between sound‐wood‐feeders and soil‐feeders. It is proposed that δ15N is therefore a possible indicator of the functional position of species in the humification process. Differences in δ13C were also observed between wood‐feeding and soil‐feeding forms.3. High values of δ15N in soil‐feeding termites suggest that nitrogen fixation is of little importance in these species.4. A wide range of isotope effects (the difference in isotope ratios between termites and their diet) was observed for both nitrogen (Δδ15N = –1.6 to + 8.8‰) and carbon (Δδ13C = –2.2 to + 3.0‰), which suggests a diversity of nutrient acquisition mechanisms within termites and diverse relationships between termites and their intestinal micro‐organisms.
Population structure of a monophagous moth in a patchy landscape
Authors: FÖRARE JONAS , SOLBRECK CHRISTER 
Published: November 2003

1. The population structure of a monophagous noctuid moth, Abrostola asclepiadis, living on a patchily distributed perennial herb, Vincetoxicum hirundinaria is described. The study took place over 5 years at a landscape scale (about 12 km2).2. Patch occupancy rates and population densities were studied in relation to patch size, degree of patch isolation, level of sun exposure and distance from the coast. In addition, flight tests in the laboratory were performed to estimate the potential dispersal capacity of the moth.3. Occupancy rates were high and the likelihood of extinction depended on patch size. Small patches were less likely to be occupied than were large patches (> 10 m2). Sun‐exposed patches were occupied for a lower proportion of years than were shaded patches. No distance effects could be discerned at the spatial scale of study, presumably because the insect is a strong flier.4. Population densities in occupied patches decreased with increasing patch size. Furthermore, insect densities tended to increase with distance from the coast. Density changes in patches were synchronized.5. The studied insect population can be described as a ‘patchy population’sensu Harrison (1991) with spatially correlated population dynamics. These dynamics are superimposed on a landscape gradient.
Enemy‐free space and the feeding niche ofan aphid
Authors: HOPKINS GRAHAM , DIXON ANTHONY 
Published: November 2003

1. The nymphs of the aphid Monaphis antennata occupy an unusual feeding niche, being restricted to the upper surfaces of leaves and petioles. The possibility that this is a predator‐avoidance strategy was investigated.2. Nymphs could be induced to feed on the under surfaces of petioles and the mortality of these nymphs was then compared with the mortality of nymphs feeding from the upper surfaces when exposed to coccinellid predators.3. Coccinellid larvae spent less time foraging on the upper surfaces of leaves and petioles than on the under surfaces of leaves and petioles.4. The nymphs occupying the upper surfaces of petioles, the normal feeding position, were encountered by the coccinellids later and less often, and fewer were attacked compared with those occupying the under surfaces.5. It is concluded that the feeding niche of the nymphs of this aphid is adaptive in that it reduces exposure to foraging predators and is the result of selection to occupy enemy‐free space.
Factors affecting host selection in an insect host–parasitoid interaction
Authors: SAIT S. M. , BEGON M. , THOMPSON D. J. , HARVEY J. A. , HAILS R. S. 
Published: November 2003

1. Many parasitoids can develop successfully in different stages of the same host but the costs of parasitism may vary between the stages. The stage of host attacked has generally been determined when there is no choice, giving a misleading impression of host selection or preference.2. The rate of parasitism by a solitary endoparasitoid, Venturia canescens, of each larval stage of the Indian meal moth, Plodia interpunctella, was examined with and without a host refuge from parasitism. In addition, when given a choice of host stages, with and without a refuge, the influence of parasitoid age on host selection was examined.3. Wasps were able to parasitize all except the first instar, but second instars experienced significantly reduced parasitism, in both refuge treatments, compared with third to fifth instars. Whilst parasitoid emergence was always significantly less when all host stages had a refuge, the reduction was only marginally significant when second instars were attacked.4. When given a choice of second‐ and fifth‐instar larvae, wasps consistently parasitized more fifth instars, both with and without a refuge. Moreover, significantly fewer second‐instar larvae were parasitized in the presence of fifth instars than when presented alone to the wasps. This pattern of parasitism was unaffected by the increasing age of the parasitoids.5. Host selection by V. canescens is discussed in terms of host–parasitoid population dynamics and structure.
Economic motivation for plant species preferences of pollen‐collecting bumble bees
Authors: RASHEED SALMAN , HARDER LAWRENCE 
Published: November 2003

1. Pollen is an essential resource for bees as it provides the proteins needed for larval development and growth. Bumble bees typically collect pollen from a limited subset of the available plant species, indicating that bees perceive qualitative and/or quantitative differences between species. Because bumble bees typically exhibit different foraging behaviours when collecting pollen than when collecting nectar, and often visit different plant species, the economics of pollen collection are subject to unique benefits and costs.2. The influences of pollen standing crop, grain volume, protein content and foraging costs on the choice of plant species by pollen‐collecting bumble bees were assessed. Pollen was collected from different plant species available to bees and these species were ranked according to eleven currencies that differentially incorporate these influences on foraging economics.3. Comparison of observed preferences at three sites with species rankings based on foraging currencies revealed that bumble bees do not assess plant species based solely on intrafloral characteristics. Instead, pollen‐foraging bumble bees are sensitive to protein availability at the site as a whole as well as foraging costs, and forage in a manner that maximizes the site‐specific efficiency of protein collection (protein collected/energetic costs). Such behaviour would promote proper larval development while maximizing forager lifespan.