bluuebunny/crossref_metadata_2025_split huggingface dataset:
Habitat use by bumble bees (Bombusspp.)
Authors: WILLIAMS PAUL H. 
Published: March 2008

ABSTRACT.Analysis of surveys of bumble bee distribution among 2 km grid‐squares in Kent revealed that some species are nearly ubiquitous among localities and abundant within each. For these ubiquitous species, Kent is near the middle of their latitudinal ranges.The other species have very restricted distributions among localities and are less abundant where they occur. For each of these local species, Kent is near the margin of its latitudinal range.The areas to which the local species are restricted are characterized by only a few of the many kinds of vegetation represented in Kent (shingle, sand dune, saltmarsh or old meadow). The ubiquitous species are also more abundant in areas with these kinds of vegetation.A random model (Gause, 1936) and the core/satellite hypothesis (Hanski, 1982a) were proposed to explain similar patterns of distribution. I conclude that their assumptions are not well supported by the results of the present analysis.A marginal mosaic model (after Andrewartha & Birch, 1954; Hengeveld & Haeck, 1981; Brown, 1984) is used to account for these patterns. This model depends on environmental factors (including resource levels and climate) affecting the economics of energy and, consequently, local persistence.It follows from the marginal mosaic model that if the level of limiting resources in a habitat declines, then it is the species closest to their distribution limits that are most likely to face local extinction. These selective extinctions would result in a form of ‘community structure’.
Maternal behaviour of a webspinner (Order Embiidina): mother‐nymph associations
Authors: EDGERLY JANICE S. 
Published: March 2008

ABSTRACT.

The life cycle of Antipaluria urichi (Saussure) (Embiidina: Clothodidae) was aseasonal and without overlap of generations within fifteen closely monitored colonies observed over a 9½ month field season. Adult females remained with their nymphs after hatch but disappeared prior to maturation of their offspring.
Time budgets of nymphs and their mothers differed significantly. Adult females spent significantly more time spinning silk than their offspring. After the nymphs hatched, the increase in area of the silk covering approximated an exponential curve, reflecting the increase in silk spinning behaviour exhibited by the adult female. These results indicate that silk may be a major contribution of the mother.
Observations suggest that silk protects embiids from some predators and from rainfall, which is often torrential in the rainforest.
In experimental field colonies, nymphs with their mothers developed significantly faster than those alone, indicating that maternal behaviours promote the development of their nymphs.
Virginity in haplodiploid populations: a study on fig wasps
Authors: GODFRAY H. C. J. 
Published: March 2008

ABSTRACT.

The fig wasps inhabiting the figs of Ficus hispidioides S. Moore in New Guinea were investigated. The galls formed by the pollinating agaonid were also inhabited by two other non‐pollinating species of wasp; a third non‐pollinating wasp caused the production of a different type of gall, and was itself parasitized by a fourth species. In all species, males were wingless and all matings occurred within the fig.
It was estimated that 2% of the pollinating fig wasps left the fig unmated. The equivalent figures for three of the non‐pollinating wasps were 2%, 4% and 23%. The significance of oviposition by virgin females to the sex allocation strategy of mated females is discussed.
The absence of fighting and male wing dimorphism were studied in the context of the predictions of their occurrence by Hamilton (1979).
The efficiency of pitfall trapping for polyphagous predatory Carabidae
Authors: HALSALL NIGEL B. , WRATTEN STEPHEN D. 
Published: March 2008

ABSTRACT.

The efficiency of pitfall trapping was investigated for seven carabid species, using time‐lapse video recording equipment, in the laboratory.
The effects of differing substrates, trap designs and seasons of collection on the capture rates of the carabids was also investigated.
Capture rate differed significantly between the species studied. The differences in capture rates between the species were unrelated to beetle size, speed of movement and diurnal behaviour.
Few differences arose in the capture rates when type of substrate or trap or season of capture were changed.
Foliar damage, parasitoids and indirect competition: a test using herbivores of birch
Authors: HAWKINS BRADFORD A. 
Published: March 2008

ABSTRACT.

The hypothesis that leaf‐chewing caterpillars and leaf miners indirectly compete via the influence of foliar damage on parasitoids was experimentally tested using the leaf miner Coleophora serratella (L.) and a complex of folivorous caterpillars on birch.
Separate experiments tested the effects of manipulating artificial or caterpillar‐induced leaf damage on parasitism of leaf miners at several spatial scales.
Parasitism of C. serratella by specialist and generalist parasitoids was independent of the extent of either collateral or leaf‐miner damage, whether experimentally or naturally induced.
Support in the literature for the hypothesis is restricted to a single case, and only on a limited spatial scale; thus, the idea that collateral damage directs parasitoid‐mediated competition among herbivores remains highly speculative.
Patterns of parasitism by Trybliographa rapae, a cynipid parasitoid of the cabbage root fly, under laboratory and field conditions
Authors: JONES T. H. , HASSELL M. P. 
Published: March 2008

ABSTRACT.

The spatial patterns of parasitism of the cabbage root fly caused by the cynipid parasitoid Trybliographa rapae (Westw.) have been studied in a laboratory system, within field cages and in a natural situation.
Continuous observations during the laboratory experiments showed the parasitoids to spend proportionately more time on the patches of high host density. This resulted in the per cent parasitism per patch being directly density dependent.
Similar patterns of parasitism were found from the field cage system, and also from experiments using the natural parasitoid population and either manipulated or natural host densities.
While mutual interference was marked in the laboratory experiments, there was little or no sign of it within the larger field cages.
Plant water deficits and insect responses: the preference of Corythucha arcuata (Heteroptera: Tingidae) for the foliage of white oak, Quercus alba
Authors: CONNOR EDWARD F. 
Published: March 2008

ABSTRACT.

The preference of Corythucha arcuata (Say) (Heteroptera: Tingidae) for the foliage of Quercus alba L. (Fagaceae) grown under water deficit was examined. Potted Q.alba saplings were grown under controlled levels of water deficit in a glasshouse. Adult C.arcuata were exposed to excised Q.alba foliage under controlled conditions in a growth chamber, and feeding preference assessed by recording the percentage of individuals feeding on leaves from each level of water deficit.
Two experiments were performed. In the first, all foliage was supplemented with water (via the petiole) to alleviate physical changes in the leaves that accompany plant water deficits. In the second experiment, leaves were not supplemented with water.
C.arcuata had no preference when presented water supplemented leaves, but preferred leaves that were fully hydrated when presented leaves that were not supplemented with water.
These results suggest that plant water deficits are important in determining the feeding preference of C.arcuata because they lead to avoidance of drought grown foliage. This avoidance may be caused by an increase in the metabolic cost to the herbivore of maintaining water balance when ingesting drought grown foliage or to an increase in foliage toughness.
Robber‐like pollinators: overwintered queen bumblebees foraging on Corydalis ambigua
Authors: HIGASHI SEIGO , OHARA MASASHI , ARAI HIROHITO , MATSUO KAZUHITO 
Published: March 2008

ABSTRACT.

The behaviour of nectar‐collecting Bombus hypocrita sapporensis Cockerell queens was observed on a population of a spring ephemeral plant Corydalis ambigua Cham, et Schlecht.
Daily patterns of activity and behaviour changed with the progress of flowering. Activity peaked shortly before sunset early in the flowering season but approximately at noon towards the end of flowering. In the peak flowering period the queens tended to visit nearby plants and to change direction often, whereas early or late in the flowering period they flew further between visits and were less likely to change direction.
Each plant was visited 0 to 24 times (mean 9.4 ±SD 5.2) by the queens during the whole flowering season.
The queens collected nectar, rarely through the front of the flowers but mostly through the spurs perforated by themselves or predecessors. At the beginning of the flowering season the illegitimate foragers often visited the front of the flowers before moving to the spurs; later, most queens quickly learned to land directly on the spurs.
Even the 59.7% of plants that were visited only by illegitimate foragers set seeds. Close observation confirmed that the illegitimate foragers opened the inner petals enclosing anthers and stigma frequently when visiting the front of the flowers before robbing, or occasionally when walking about on the flowers or collecting nectar through the perforated spurs.
Life history strategy and egg diapause in the intertidal collembolan Anurida maritima
Authors: WITTEVEEN J. , VERHOEF H. A. , HUIPEN T. E. A. M. 
Published: March 2008

ABSTRACT.

In a field survey of 1 year the intertidal collembolan Anurida maritima (Guérin) was found to be a univoltine species. Every year in early May a new generation emerges from eggs that overwinter. The first animals become adult in July. Almost all eggs laid in summer do not hatch, but undergo a period of diapause. Diapause is terminated in autumn by temperatures below 5°C. However, due to the low temperatures in winter further egg development is suppressed until spring.
The adult animals die, mainly in autumn. One of the causes of mortality may be starvation. In late autumn body size decreases and glycogen and lipid content are lower.
It is argued that in autumn due to low temperatures A.maritima, which forages during low tide on the open shore and seeks refuge underground before the incoming tide, is too sluggish to find food in the limited period of low water. This probably explains why this cosmopolitan species has developed a strategy to survive the winter in the temperate zone in the egg stage.
The population characteristics of the brown plant hopper, Nilaparvata lugens, in the Philippines
Authors: COOK A. G. , PERFECT T. J. 
Published: March 2008

Abstract. 1. Population characteristics of the brown planthopper, Nilaparvata lugens (Stål), were investigated over eight growing seasons on rainfed rice in the Philippines.2. Three nymphal generation peaks were observed in most seasons. The third peak was not always the largest and peaks varied considerably in size from season to season.3. Generation peaks were less distinct at a second sampling site within an irrigation system, possibly associated with increased asynchrony of planting and the consequent increased immigration potential.4. Mortality was highest for eggs and first instar nymphs. Egg to adult survivorship was estimated as 1–12%.
Nesting of Afrotropical Oniticellus (Coleoptera, Scarabaeidae) and its evolutionary trend from soil to dung
Authors: DAVIS A. L. V. 
Published: March 2008

Abstract. 1. Oniticellus egregius Klug constructs brood ovoids of dung in the soil immediately under the edge of animal droppings. Each successive brood ovoid is enveloped within a soil shell. After completion of brood construction, loose earth is cleared from around the broods to produce a brood chamber. The immatures are then abandoned as eggs or first instar larvae.2. O.planatus Castelnau and O.formosus Chevrolat usually construct brood balls of dung within animal droppings. Each brood is progressively enlarged by the addition of further dung after egg‐laying. This enlargement is slight in O.planatus and marked in O.formosus. Parental females of both species remain in the brood chambers during development of the immatures which are abandoned principally as pupae.3. Under very moist experimental conditions, O.planatus buries dung and constructs broods shallowly in the soil. Such nests are frequently connected to the pad by a short tunnel.4. From a consideration of behavioural patterns it is suggested that the specialized nesting habits of these species have been derived from those of dung‐burying ancestors similar to the modern genus, Euoniticellus, through reduction and loss of tunnelling in the soil.
Population studies of the beech leaf mining weevil (Rhynchaenus fagi) in Ireland and Scotland
Authors: DAY KEITH R. , WATT ALLAN D. 
Published: March 2008

Abstract. 1. Population budgets for Rhynchaenus fagi, based for the most part on samples of beech leaves taken in June, were constructed for a 10‐year period (Northern Ireland) and a 3‐year period (Scottish borders).2. There were years of sustained population growth and sustained decline, but not enough evidence to suggest a cycle. Similar population levels were found at both sites in all but one year.3. Key factors were associated with the adult stage, although egg mortality may also make a significant contribution to population change.4. Unknown sources of mortality embodied in the residual mortality were also suspected of acting in a density dependent manner, compensating for variation in parasitism.5. Death rate of larvae within mines was related to May temperature in Northern Ireland, but not so clearly in Scotland.
Reproductive cost of flight capability: a comparison of life history traits in wing dimorphic planthoppers
Authors: DENNO ROBERT F. , OLMSTEAD KAREN L. , McCLOUD ERIC S. 
Published: March 2008

Abstract. 1. Reproductive costs associated with flight capability were evaluated in the wing dimorphic planthopper, Prokelisia dolus Wilson, by comparing the life history of traits of winged (macropterous) and flightless (brachypterous) females under controlled laboratory conditions.2. Macropters with large thoraces and fully developed wings maintain a greater investment in flight apparatus than brachypters with small thoraces and reduced wings.3. Associated with greater flight capability in the macropter of P.dolus are shorter adult life, decreased total fecundity, and delayed age at first reproduction compared to brachypterous females.4. Under field conditions where mortality is high, the difference in realized fecundity between the two wing forms living on similar resources is further exaggerated with the brachypter having the greater advantage.5. When the life history traits of the wing forms of P. dolus are compared with traits for nine other species of planthoppers, two similarities emerge. First, the preoviposition period of the macropterous wing form is always longer than that for the brachypter resulting in a reproductive delay. Second, most studies show that macropters are less fecund than brachypters.6. There is no general tendency among planthopper species for macropterous adults to live fewer days or develop more slowly as nymphs compared to their flightless counterparts.7. The reproductive delay and reduced fecundity of the volent wing form of planthoppers supports the notion that flight capability is costly and that phenotypic trade‐offs between flight and reproduction exist.
Nonlinear responses of spider mites to drought‐stressed host plants
Authors: ENGLISH‐LOEB GREGORY M. 
Published: March 2008

Abstract. 1. This study examines the shape of the population response curve of the two‐spotted spider mite, Tetranychus urticae Koch, feeding on bean plants, Phaseolus vulgaris L., which have been subjected to one of a range of drought stresses.2. Abundance of spider mites declined at slight drought stress, increased at intermediate intensities of stress, and declined again at severe stress.3. Fecundity showed the same pattern found for total abundance. Developmental rates of immatures, on the other hand, generally increased with stress intensity. Survivorship of immatures and adult females appeared unrelated to stress intensity.4. These results indicate that responses of mites to drought‐stressed beans are nonlinear. Such a pattern helps explain contradictory results obtained for spider mites and other arthropod herbivores.
Sex allocation and egg distribution of an autoparasitoid, Encarsia pergandiella (Hymenoptera: Aphelinidae)
Authors: HUNTER MARTHA S. 
Published: March 2008

Abstract. 1. Encarsia pergandiella Howard females develop as primary parasitoids on immature whiteflies, and males develop as secondary parasitoids on females of their own or a related species. The hypothesis that the sex ratio reflects the relative abundance of the two host types was tested in the laboratory using petri dish arenas with varying proportions of early fourth instar greenhouse whitefly (Trialeurodes vaporariorum (West.)) (primary hosts) and pupal female E.pergandiella (secondary hosts). Egg distribution was analysed with respect to sex ratio, super‐parasitism and host discrimination.2. The proportion of primary and secondary hosts parasitized in each treatment reflected the relative availability of each host type. Thus females presented with 75% primary hosts laid more female eggs than male. However, in all treatments, a greater proportion of secondary hosts were parasitized than would be expected from the proportion of secondary hosts available. This indicates that more male eggs were laid than expected.3. More secondary hosts than primary hosts were superparasitized.4. Host discrimination analysis using a new test statistic showed that females generally laid eggs at random with regard to previous parasitism of primary or secondary hosts. However, females in one treatment with 50% of each host type appeared to preferentially oviposit in secondary hosts which did not contain any eggs.
An alternative mating system in small male insects
Authors: McLACHLAN ATHOL , NEEMS RACHEL 
Published: March 2008

Abstract. 1. Small males of all midge (Diptera: Chironomidae and Chaoboridae) species thus far examined (one chaoborid and six chironomids) are rare in mating swarms. They are found instead in vegetation adjacent to the swarm.2. We show that it is here that females aggregate prior to embarking on mate acquisition flights. In the vegetation females appear to be accessible to males staying behind.3. Such behaviour in small males may exploit the mate‐attracting activities of large males in the swarm and may, at the same time, reduce competition and conserve energy.4. The evolution and maintenance of these size‐related types of mating behaviour are discussed.
Regulation of host diapause by an insect parasitoid
Authors: MOORE SANDRA D. 
Published: March 2008

Abstract. 1. The interaction between larval development and parasitism by the braconid wasp Cotesia koebelei (Riley), was investigated in a population of the butterfly Euphydryas editha (Boisduval) (Nymphalidae). In this population, the butterfly host has an obligatory overwintering larval diapause.2. It was found that E. editha larvae harbouring parasitoids were more likely to pass through an extra feeding instar before entering diapause than were non‐parasitized conspecifics.3. In addition, some individuals that were experimentally exposed to multiple parasitoid attacks bypassed diapause completely; these larvae passed through five or six feeding instars, reaching sizes typical of final instar post‐diapause larvae.4. The observed effect of superparasitism occurred regardless of whether the host larvae subsequently produced mature parasitoids, suggesting that parasitoid attack is sufficient to invoke the response.5. It is proposed that the parasitoid C.koebelei regulates the number of pre‐diapause feeding instars of its insect host E. editha, and that some component of the female venom, injected at oviposition, is responsible for this regulation.
Variations in the life‐history parameters of Hemipyrellia ligurriens (Diptera: Calliphoridae) in response to larval competition for food
Authors: SO PING‐MAN , DUDGEON DAVID 
Published: March 2008

Abstract. 1. Larval rearing densities of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) in standardized carrion were manipulated in order to investigate changes in life‐history parameters in response to larval competition for food.2. Competition was of the typical scramble type. Survivorship remained high at densities up to 32 larvae g liver‐1 but decreased rapidly as larval density increased further.3. Emergent adults were undersized with reduced fecundity and longevity. Variations in adult body size apparently reduced the effects of competition on larval mortality.4. Females of dry weight corresponding to only 10.4% of the potential maximum emerged at the highest rearing densities of 128 larvae g liver‐1. However, these females had a nearly four‐fold increase in reproductive investment (per unit weight) when compared to the largest individuals.5. The duration of larval development declined when competition was intense (i.e. at high larval densities).6. The short adult life of H.ligurriens, combined with the unpredictability of larval habitat availability, may reduce the value of long‐range dispersal so that females ‘do better’ by maintaining reproductive investment despite a concomitant decline in dispersal ability.
Predator‐mediated coexistence in laboratory communities of mycophagous Drosophila (Diptera: Drosophilidae)
Authors: WORTHEN WADE B. 
Published: March 2008

Abstract. 1. This laboratory experiment examined the effects of interspecific competition and predation by Ontholestes cingulatus Gravenhorst (Coleoptera: Staphylinidae) on three species of mycophagous Drosophila (Diptera: Drosophilidae): D.tripunctata Loew, D.falleni Wheeler and D.putrida Sturtevant.2. Single‐species and three‐species assemblages were exposed to single commercial mushrooms on wet pine shavings in 200 ml culture bottles. A predacious rove beetle (Ontholestes cingulatus) was present in half of the three‐species replicates. The stocked adult flies and beetles were removed after 4 days, and the number, biomass and mean mass of emerging progeny was recorded.3. For all three species the abundance and biomass of the progeny emerging in the ‘no predator’ communities' was significantly less than for the progeny emerging in single‐species replicates, suggesting an interspecific competitive effect. D.tripunctata was the competitive dominant; it emerged in abundance from all seven three‐species ‘no predator’ communities while D.putrida and D.falleni were often excluded.4. The decrease in production was attributed to strong interspecific competition among larva and not interference among ovipositing adults.5. Predation on ovipositing adults significantly reduced the number and biomass of D.tripunctata progeny emerging, and indirectly facilitated the number and biomass of emerging D.falleni and D.putrida.Predation on adults reduced larval recruitment, relaxed larval competition, and released the inferior competitors.