bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predation and parasitism in a tropical herbivore community
Authors: MEMMOTT J. , GODFRAY H. C. J. , BOLTON B. 
Published: March 2008

Abstract.

Crawling predators were excluded from bamboos attacked by three species of chrysomelid leaf miner in two plots of tropical dry forest in Costa Rica.
The percentage of predated mines declined from an average of 61 % to an average of 29% in plots where crawling predators had been excluded. There were concomitant increases in successful beetle emergence and in the numbers of beetles attacked by parasitoids.
The probability of a miner that had escaped predation being attacked by a parasitoid was the same in experimental and control treatments, indicating that the risks of predation and parasitism are statistically independent.
The results were consistent across species and plots with the exception of one species in one plot where emergence was lower in the exclusion treatment than in the control because of very severe parasitoid attack. This result is unexplained.
Limited observations, and evidence from the type of damage observed on predated mines, suggest that the most important crawling predators are ants.
Overdispersion of Allothrombium pulvinum larvae (Acari: Trombidiidae) parasitic on Aphis gossypii (Homoptera: Aphididae) in cotton fields
Authors: ZHANG Z.‐Q. , CHEN P.‐R. , WANG K. , WANG X.‐Y. 
Published: March 2008

Abstract.

Dispersion patterns of the protelean parasite, Allothrombium pulvinum Ewing, among individuals of an aphid host, Aphis gossypii Glover, were examined during spring 1991 in several cotton fields in Jiangsu Province, China.
The variance‐to‐mean ratios (i.e. dispersion index) of larval mites per host were greater than 1, indicating that the mite parasites were overdispersed among aphid hosts. The variance increased with the mean according to the power law, variance = 1.51 mean106, which explained 99.7% of the variation in the data.
The negative binomial distribution adequately describes the patterns of larval mite dispersion among aphid hosts in eight out of ten populations. The degree of clumping (1/k) decreased curvilinearly with parasite density (mites per host).
Mites were more clumped among adult aphids than among immature ones.
Ecological and evolutionary consequences of mite overdispersion within host populations are discussed. The role of Allothrombium in pest control is also discussed.
Diversity and faunistics of small moths (Microlepidoptera) in Bornean rainforest
Authors: ROBINSON GADEN S. , TUCK KEVIN R. 
Published: March 2008

Abstract.

Samples of Microlepidoptera (including Pyraloidea) collected at light in mangrove forest, lowland mixed dipterocarp forest, and montane oak‐laurel forest in Borneo are compared.
Diversity (Williams' alpha) is very high in lowland forest, with a value of 414; it is lower, 226, in montane forest and very much lower, 47, at the edge of mangrove forest.
There is some evidence that apparent diversity increases with accumulation of samples.
Samples from the three forest types have very few species in common and come from separate assemblages.
Pyraloidea in samples taken 1km apart in lowland forest represent an assemblage common to the two sites but Microlepidoptera samples appear to represent slightly different assemblages.
There are no abundant species in lowland or montane forest: species with more than ten individuals comprised less than 4% of the samples. Four common species in mangrove forest accounted for 34% of the sample.
The proportion of Tineoidea, Gelechioidea and Pyraloidea is lower in montane forest than in lowland forest, while that of Yponomeutoidea and Tortricoidea is higher.
Just eight families of Microlepidoptera account for 90% of the species in samples from all three forest types.
The number of species of moths in Borneo is suggested to be in excess of 8500.
Efficient floret inspection by honeybees in capitula of Carduus acanthoides
Authors: GIURFA MARTIN , NÚÑEZ JOSUÉ A. 
Published: March 2008

Abstract. 1. The floret inspection by honeybees Apis mellifera ligustica on inflorescences of Carduus acanthoides was studied in a natural patch. First‐day stage capitula were protected with a net hood against insect visits. The next day, the net hood was removed at the time of maximal nectar accumulation, allowing a bee to visit the inflorescence. Walking trajectories on the capitula, the number of florets inspected and the duration of the visit were recorded. After the bee's departure, the inflorescence was cut off and analysed in the laboratory to determine the presence or absence of nectar in each of its florets.2. Bees made inspection trajectories without a defined systematic pattern.3. The number of floret inspections performed represented a high percentage of the available florets (57.37 ± 2.81%; mean ± SE; n = 8).4. The number of depleted florets coincided with the number of floret inspections.5. The number of times a floret is visited in a bee's trajectory is non‐random.6. Strategies that might account for this high foraging efficiency are discussed.
The community ecology of Aedes egg hatching: implications for a mosquito invasion
Authors: EDGERLY JANICE S. , WILLEY MICHELLE S. , LIVDAHL TODD P. 
Published: March 2008

Abstract. 1. A recently introduced treehole mosquito from Asia, Aedes albopictus, is spreading throughout eastern North America, especially in tyre‐refuse piles. Previous studies have identified inhibitory effects of larvae on egg hatch as a potential population regulatory mechanism within Aedes. Larva‐egg interactions may also occur between species. This experiment assesses the ability of larvae of A. albopictus and two possible competitors in North America, A.triseriatus and A.aegypti, to suppress hatching of conspecific and congeneric eggs.2. We exposed eggs of each species to varying combinations of larval species and density for 24h and assessed subsequent hatch rates. Aedes albopictus eggs exhibited the lowest level of inhibition when exposed to high larval densities; moreover, at the lowest larval density they imposed the most intense interspecific hatch inhibition.3. Discretionary hatching in response to larval density may influence community composition by promoting the spread of A.albopictus, perhaps even leading to its dominance within North American Aedes communities.
Effects of herbivory and genotype on growth and survivorship of sand‐dune willow (Salix cordata)
Authors: BACH CATHERINE E. 
Published: March 2008

Abstract.

The response of different clones of sand‐dune willow, Salix cordata, to herbivory by a specialist herbivore, Altica subplicata, was studied in three glasshouse experiments. Plants were caged and exposed to three herbivory treatments: no beetles, low number of beetles, and high number of beetles.
Plants consistently had significantly higher growth rates in the absence of herbivory than under conditions of low or high herbivory (1.5–6 times higher).
Herbivore treatment influenced mortality from drought stress; more plants from the low and high herbivory treatments (40% and 80%) died from drought stress than did control plants (0%).
Clone genotype significantly influenced growth rates and the susceptibility of plants to drought stress. However, clones showed similar growth responses to herbivory, suggesting a lack of genetic variation in tolerance or resistance to herbivory.
Effects of extended and repeated exposures to low temperature on mortality of the peach‐potato aphid Myzus persicae
Authors: HOWLING G.G. , BALE J.S. , HARRINGTON R. 
Published: March 2008

Abstract.

The survival of adult and first‐instar Myzus persicae reared at 20°C and 10°C was investigated after brief (1 min) exposure in the absence of plant material to temperatures between −5°C and −25°C, and extended exposures on plants of 1–10 days at a constant 5°C, 3°C and −5°C and a 24 h cycling regime between 5°C (18 h) and −5°C (6 h).
Life stage, rearing temperature, period of exposure and temperature regime all had a significant effect on the ability of aphids to survive cold. The effects of life stage and rearing temperature were most noticeable following exposure to cycling temperatures and extended exposures at −5°C, and least apparent after 1 min exposures at lower sub‐zero temperatures.
Mortality following exposure to temperatures cycling between −5°C and 5°C was greater than that at 3°C (the mean of the cycling temperatures) and less than at a constant −5°C, suggesting that when temperatures fluctuate by a few degrees around 0°C the minimum temperature may affect survival to a greater extent than the mean.
These results suggest that an overwintering population of acclimated M.persicae would persist without significant mortality after a period of 7–10 days with −5°C frosts each night.
Host‐plant influence on the population ecology of the jack pine budworm, Choristoneura pinus (Lepidoptera: Tortricidae)
Authors: NEALIS V. G. , LOMIC P.V. 
Published: March 2008

Abstract.

Newly‐emerged, second‐instar jack pine budworm (Choristoneura pinus Freeman) establish spring feeding sites preferentially in the pollen cones of their host tree, Pinus banksiana Lamb.
Laboratory studies showed that the rate of establishment and survival of jack pine budworm on pollen cones was high throughout the entire spring emergence period of the insect.
In contrast, the rate of establishment and survival of jack pine budworm on vegetative buds was very poor early in the spring. Vegetative buds were only acceptable as feeding sites to the jack pine budworm for a relatively brief period in late spring.
Field studies showed that the change in population density of jack pine budworm during the spring emergence stage, as expressed by k‐values, was a function of the abundance of pollen cones in the stand. Population reduction was greatest in those stands with the fewest pollen cones.
Direct measurement of spring dispersal by jack pine budworm showed that dispersal and consequent losses to the budworm population were greatest in stands with the fewest pollen cones.
We conclude that changes in the density of jack pine budworm are strongly influenced by production of pollen cones in the host stand. Because pollen cone production is related to previous years of defoliation by the jack pine budworm, we propose that pollen cones act as a density‐dependent factor governing the density of early‐stage jack pine budworm.
The resulting dynamics are compared to those of other budworm species and used to explain observed regional and temporal patterns of jack pine budworm outbreaks.
Alternative seed defence mechanisms in a palo verde (Fabaceae) hybrid zone: effects on bruchid beetle abundance
Authors: SIEMENS DAVID H. , RALSTON BARBARA E. , JOHNSON CLARENCE DAN 
Published: March 2008

Abstract.

We asked three questions about the patterns of relative abundance of insect herbivores across host plant taxa at a palo verde hybrid zone. (1) What is the morphological structure of the hybrid zone and does this suggest a certain pattern of introgression? (2) How are putative parental seed defence mechanisms expressed in hybrid plants? (3) Do ovipositing females prefer host plant taxa on which their offspring have best survivorship?
Morphologically, hybrids were either intermediate or tended to resemble one parental species. Previous studies have suggested that unidirectional introgression results in loss of parental defence mechanisms against herbivores. Hybrid plants in general lacked seed coat resistance and early pod abscission which are known to act as plant defence mechanisms against bruchid beetles in the parental palo verde trees.
All other sources of bruchid mortality that we examined did not vary across parental and hybrid taxa, with the possible exception of egg parasitism which occurred at a lower frequency on one parental palo verde species.
Thus, survivorship of bruchid offspring should be greater on hybrid palo verdes.
Patterns of egg densities suggested that females may prefer hybrid hosts in some years but not others. An oviposition choice experiment conducted in the field, however, showed bruchids have no preference for hybrids over one of the parental species.
These results suggest that some insect herbivores may have higher densities on hybrid host plants because they are less resistant.
Influence of inter‐tree variation in time of budburst of white spruce on herbivory and the behaviour and survivorship of Zeiraphera canadensis
Authors: QUIRING DAN T. 
Published: March 2008

Abstract.

Field studies were carried out during 4 years to determine the effects of inter‐tree variability in the time of budburst of white spruce, Picea glauca Moench (Voss.), on the distribution, behaviour and survivorship of, and herbivory by, the spruce bud moth, Zeiraphera canadensis Mutt. & Free.
Differences between trees in herbivory, bud moth density and survivorship were inversely related to the mean date of budburst. The most and least susceptible half‐sib‘families’evaluated were the first and last to flush, respectively. Differences in herbivory for trees in two families with similar phenologies were partially due to oviposition preference.
Oviposition and larval survivorship were highest on trees in the most susceptible families. Although egg hatch was more closely synchronized with budburst in warm than in cool springs, between tree differences in the time of budburst were consistent over years.
Coastal insect herbivore populations are strongly influenced by environmental variation
Authors: STILING PETER 
Published: March 2008

Abstract.

Pissonotus quadripustulatus is a brachypterous planthopper that feeds on the clonal salt marsh plant, sea oxeye daisy, Borrichia frutescens. Asphondylia borrichiae is a macropterous gall fly that creates galls on the apical meristems. Most Borrichia occurs in isolated patches consisting of more than one genotype.
Densities of Pissonotus and Asphondylia do not significantly differ within patches but they do differ between patches. I tried to find out why some patches of Borrichia support consistently higher densities of Pissonotus and Asphondylia than others.
Reciprocal transplants of Borrichia between patches showed that for both Pissonotus and Asphondylia recipient site (local environment) had a strong effect on population densities. However, the best sites for Asphondylia were generally the worst sites for Pissonotus and vice versa.
Donor site (local plant genotypes) was not significant for Pissonotus but was marginally significant for Asphondylia. However, for Asphondylia recipient site had a greater effect. Local plant genotype effects may be greater for gall‐forming insects, which tend to be specialists, than for more generalist sapsucking insects.
Within‐tree and among‐tree variation in growth of Epirrita autumnata on mountain birch leaves
Authors: SUOMELA JANNE , NILSON ANNA 
Published: March 2008

Abstract.

We studied among‐tree and within‐tree variation in the growth of larvae of a geometrid, Epirrita autumnata, on mountain birch (Betula pubescens ssp. tortuosa) leaves at different hierarchical levels: among trees (genets), among ramets within trees, among branches within ramets, among shoots within branches and among leaves within shoots. We used only short shoot leaves, which burst simultaneously in spring.
Trees accounted for most of the variation in larval growth rate, but there was substantial variation also among ramets within trees, among branches within ramets, and among short shoots within branches. Variation among leaves within short shoots was negligible. When the probabilities from different experiments were combined, the differences were statistically significant at the tree, ramet and branch levels, and approached significance at the shoot level.
In different experiments, larval growth was from 9% to 54% lower on the worst tree than on the best tree of the experiment. On average, larval growth rate was in different experiments from 11% to 32% lower on the worst ramet than on the best ramet within tree, from 8% to 18% lower on the worst than on the best branch within ramet, and from 12% to 30% lower on the worst than on the best shoot within branch.
The amount of among‐and within‐tree variation shown by our results may have ecological and evolutionary implications: among‐tree variation should select for discrimination by ovipositing females and dispersing larvae, within‐tree variation should select also for optimal foraging behaviour of larvae.
Energy budget of swarming male mosquitoes
Authors: YUVAL BOAZ , HOLLIDAY‐HANSON MERRY L. , WASHING ROBERT K. 
Published: March 2008

Abstract.

The objective of this study was to determine, in the field, the energetic costs of swarming for male Anopheles freeborni (Diptera: Culicidae). By comparing the caloric contents of resting males to marked males captured after swarming, we established when sugar feeding takes place, what energy source is used to fuel swarming flight, and how much energy is invested in this activity.
Sugar‐feeding takes place sometime during the night after swarming is concluded. Nectar sugars are therefore not immediately available to fuel flight. Stored sugars (trehalose and glucose) and glycogen are the primary sources of energy for flight. Lipids are not used to fuel flight but may be used in resting metabolism.
Male size is not related to feeding success. For males of all sizes, swarming consumes more than 50% of available calories. Accordingly, the ability of an individual to find and exploit nectar sources will greatly affect reproductive success.
Activity patterns of females of the solitary bee Anthophora plumipes in relation to temperature, nectar supplies and body size
Authors: STONE GRAHAM N. 
Published: March 2008

Abstract.

Patterns of activity at a large nesting aggregation and at foraging sites are described for females of the solitary bee Anthophora plumipes (Pallas). Changes in the quality and quantity of the resource collected by females provisioning cells are related to variation in female body mass and microclimate.
Activity at the nest site demonstrated relationships with aspects of the thermal environment experienced by A.plumipes. Measures of temperature showing significant relationships differed for females in different stages in the nesting cycle exhibiting characteristically different behaviour patterns.
Larger females emerged from nest tunnels earlier in the morning and provisioned cells at lower ambient temperatures than smaller individuals. Body size therefore predicts reproductive success at low ambient temperatures.
Pollen and nectar loads carried by females increased with ambient temperature. Because only one cell is completed per day and the size of offspring is determined by the quality and quantity of resource provided by the mother, the body size of individuals emerging in the following season will depend on interactions between climate and body size, in addition to any heritable component.
Variation in activity levels at foraging sites is attributed not only to thermal considerations, but also to variation in the quality of rewards available at different floral sources.
The effects of crop diversification on herbivorous insects: a meta‐analysis approach
Authors: TONHASCA ATHAYDE , BYRNE DAVID N. 
Published: March 2008

Abstract.

We used a meta‐analysis to evaluate the hypothesis that diversified crops are subject to lower density of herbivorous insects. This method consists of integrating findings of independent studies by calculating the magnitude of treatment effects (effect size).
A literature review covering a period of over 10 years yielded twenty‐one studies that contained sufficient information for the meta‐analysis. The data were analysed according to three criteria: yearly replications of the same study were considered independent data so that research repeated over time would have greater weight; a second meta‐analysis was conducted with results of only 1 year because of possible lack of independence between results of the same study; the third approach was to remove studies involving Brassica spp. from the analysis because they are redundant from the standpoint of testing a general hypothesis of crop diversification.
The three analyses resulted in effect sizes of 0.50, 0.35 and 0.27, respectively, and all were statistically significant. These results correspond to 69%, 63% and 60% differences between average insect densities for treatment (diversified crops) and control groups.
We considered the last criterion for data analysis as the most appropriate because of lowest bias from non‐independence between samples. Therefore we concluded that crop diversity caused moderate reduction of herbivorous insect populations.
The implications and limitations of meta‐analyses are discussed.
Intraspecific variability in host plant quality and ovipositionaI preferences in Eucheira socialis (Lepidoptera: Pieridae)
Authors: UNDERWOOD DESSIE L. A. 
Published: March 2008

Abstract.

This study investigates interactions between Eucheira socialis (Pieridae: Lepidoptera), a strict monophagous herbivore, on Arbutus xalapensis (Ericaceae), a host plant with few herbivores. This tight association of insect on plant has many attributes conducive to reciprocal rather than diffuse evolution.
An indirect way of testing plant–insect coevolutionary theories is to test for the necessary conditions for reciprocal evolution in ecological time. Two conditions for coevolution were studied: (1) host plants vary in their suitability for larval growth and development, and (2) ovipositing insects discriminate among these plants based on their relative suitability.
Large differences in host plant suitability were found and relative differences were consistent from year to year.
There was no evidence that female insects based their ovipositional decisions on relative tree quality, which implies that factors other than host plant quality are involved in the maintenance and evolution of oviposition behaviour in Eucheira.
Of seven factors known to influence ovipositional preferences of insects among plants independent of potential larval success, the most likely causal factor in this system is the ability of females to balance a time/energy budget for finding potential oviposition sites, discriminating among them, and actually ovipositing.
Seasonal polyphenism in the wild: survey of wing patterns in five species of Bicyclus butterflies in Malawi
Authors: WINDIG JACK J. , BRAKEFIELD PAUL M. , REITSMA NICO , WILSON JOHN G. M. 
Published: March 2008

Abstract.

For three successive years Bicyclus butterflies were caught on a daily basis at a field site in Malawi.
Over 5000 butterflies, belonging to five species, were captured. Eight characters describing their plastic wing pattern were measured and analyzed.
Broadly speaking, the plasticity is similar for all species, with the wet season forms having conspicuous wing markings (e.g. eyespots), and dry season forms lacking these markings.
However, at a more detailed level, each species has its own specific form of plasticity with especially clear differences in the number of intermediate forms.
Females generally show a higher degree of plasticity than males.
The relative frequencies of intermediate forms and the difference between the sexes are associated with differences between the species in their preference for more open habitats or forests.
The species with the most divergent plasticity is also ecologically and phylogenetically comparatively distant from the others.