bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenotypic plasticity and geographical variation in the pre‐reproductive period of Autographa gamma (Lepidoptera: Noctuidae) and its implications for migration in this species
Authors: HILL JANE K. , GATEHOUSE A. GAVIN 
Published: March 2008

Abstract.

Adults of the noctuid moth Autographa gamma undertake seasonal migrations into areas where they are unable to breed continuously. Individuals migrate into Britain each spring, and offspring of these migrants probably return in autumn to over‐wintering areas in North Africa and the Middle East. However, the existence of these return migrations has been questioned.
Insects usually migrate during the adults' pre‐reproductive period (PRP). The length of this period is therefore an index of migratory potential since individuals with longer PRPs have more time to express their potential for flight and to travel further before becoming sexually mature.
Offspring of insects from Morocco, Britain and Germany showed that, under both long and short photoperiods, PRP increased with latitude over the range 34–53°N. There were significant genotype—environment interactions in the effect of photoperiod on length of PRP.
However, PRPs of offspring from insects collected in Sweden were no different under a long photoperiod from those of offspring collected further south, and were significantly shorter under a short photoperiod than those of insects from Morocco.
With the exception of Swedish moths, offspring from insects collected at higher latitudes had longer PRPs and, therefore, the potential to travel further during migrations. The ability of some individuals to respond to environmental cues signalling habitat deterioration will further increase their potential to return to over‐wintering areas further south.
Do host alternating aphids know which plant they are on?
Authors: KUNDU R. , DIXON A. F. G. 
Published: March 2008

Abstract.

To determine whether an aphid is ‘aware’ of which plant it is on, clones of a host alternating aphid, Cavariella aegopodii Scop., reared on its primary (Salix) or secondary (Daucus) host, were subjected to autumnal conditions.
Old clones produced males and egg laying females when exposed to autumnal conditions on the primary host but autumnal migrants and males when on the secondary host.
Unlike some other host alternating aphids, Cavariella did not have to spend a period on the secondary host or go through the spring migrant stage before producing sexuals.
The adaptive significance of a host alternating aphid being ‘aware’ of which host plant it is on is discussed in the light of these results.
Contest competition among Maculinea rebeli butterfly larvae in ant nests
Authors: THOMAS J. A. , ELMES G. W. , WARDLAW J. C. 
Published: March 2008

Abstract.

Caterpillars of the myrmecophilous butterfly Maculinea rebeli showed strong evidence of contest competition when introduced at high densities to laboratory nests of Myrmica ants.
This is attributed to the direct feeding of caterpillars by workers, which select a few individuals to nurture when food or ant numbers are limiting. It contrasts with published data for a congener, Maculinea arion, which has predacious larvae and experiences scramble competition in crowded ant nests.
Worker ants from two Myrmica rubra colonies (I and II) were used to found the laboratory nests hosting Maculinea rebeli. Nests from each source reared a similar biomass of Maculinea, but whereas those containing M. rubra I workers reared eight to ten lightweight caterpillars each, cultures from colony II reared half as many caterpillars, each of about double the weight.
Differences in nest capacity may be due to the different social structures of colonies I and II at the start of the experiment.
Calculation of collated indices of abundance of butterflies based on monitored sites
Authors: MOSS D. , POLLARD E. 
Published: March 2008

Abstract.

The Butterfly Monitoring Scheme uses regular transect counts on fixed sites to establish annual indices of abundance of butterfly species in the United Kingdom. The annual change in collated index for each species has hitherto been calculated as a simple ratio between total counts summed over all participating sites.
A revised method for calculation of collated indices is proposed, which applies a logarithmic transformation to site values so as to downweight the influence on the index of the sites with greatest numbers of a species. Zero counts are handled comparably with non‐zero values. An alternative method using geometric mean ratios is also examined.
Indices calculated using the logarithmic transformation are compared with those calculated using the traditional method. Two internal tests of dependency of collated indices on the sites with highest abundance are made. Another evaluation uses regression analysis for the effects of temperature and rainfall on collated indices of butterfly abundance.
The first internal test shows that logarithmic transformation reduces the dependence of the collated index on the sites of highest abundance for twenty‐five out of twenty‐seven species examined; while a second test shows a reduction for twenty‐six out of forty‐two species, and an increase for one species. The number of significant regressions on temperature variables increases with the use of the logarithmic transformation from 11% to 13% of tests made, and on rainfall from 10% to 11%.
The geometric mean ratio method introduces considerable biases in its treatment of zero values, for which a remedy is not available.
Although the revised collated indices calculated using logarithmic transformation are broadly comparable with traditionally calculated values, the reductions in dependency on sites with the most abundant populations render the revised indices less subject to perturbation due to local ‘noise’, and so more suitable for research on factors influencing butterfly abundance.
Ecology of body size in Drosophila buzzatii: untangling the effects of temperature and nutrition
Authors: THOMAS RICHARD H. 
Published: March 2008

Abstract.

A method of separating the effects of two important determinants of body size in natural populations, temperature of larval development and level of larval nutrition, by making measurements of thorax length and wing length of adult flies is investigated.
I show that at any given time variation in body size of Drosophila buzzatii from two sites in eastern Australia is determined primarily by variation in the quality of nutrition available to larvae.
Throughout the year adult flies are consistently at least 25% smaller in volume than predicted for optimal nutrition at their predicted temperature of larval development.
Nutritional stress is therefore a year‐round problem for these flies.
Measurements of adult flies emerging from individual breeding substrates (rotting cactus cladodes) show that there is substantial variation among these substrates in the nutrition available to larvae.
This method will allow study of spatial and temporal variation in the temperature of larval substrates and in the nutritional resources available to flies in natural populations.
Fluctuating asymmetry and lifetime mating success are correlated in males of the damselfly Coenagrion puella (Odonata: Coenagrionidae)
Authors: HARVEY IAN F. , WALSH KITT J. 
Published: March 2008

Abstract.

The influence of fluctuating asymmetry on lifetime mating success of males of the damselfly Coenagrion puella (Odonata: Coenagrionidae) was investigated. Fluctuating asymmetry was measured as the difference in length of left and right fore and hind wings.
Males with more symmetrical wings enjoyed higher lifetime mating success.
Larger males, in contrast to a previous study of this species, also had higher mating success. This may be attributed to differences in the weather conditions prevailing at the time of the studies.
The arthropod predators of ant‐mimetic and aposematic prey: a serological analysis
Authors: McIVER JAMES D. , TEMPELIS CONSTANTINE H. 
Published: March 2008

Abstract.

ELISA (enzyme‐linked immunosorbant assay) was used to identify the arthropod predators of two common herbivores of a desert lupine: the aposematic plant bug Lopidea nigridea and the ant‐mimetic plant bug Coquillettia insignis.
Despite the fact that the prey are closely related, the two antisera were sufficiently specific to distinguish between the antigen against which they were formed and the antigen of the other species: both antisera were 3 times as reactive against their homologous antigen as they were against their heterologous antigen.
In tests on gut contents of field‐collected predators, ELISA results were generally consistent with laboratory no‐choice data for the five most common arthropod species on lupine: there was a strong correlation between attack rates for each predator‐prey pair as measured in the laboratory, and per cent positive reactions in ELISA as measured using field‐collected predators. In particular, L.nigridea antiserum was shown to be significantly less reactive against the crab spider Xysticus montanensis when compared to C.insignis antiserum, paralleling results of laboratory no‐choice experiments.
The usefulness of serological analysis as a tool for arthropod trophic link identification is discussed.
A nectar‐secreting gall wasp and ant mutualism: selection and counter‐selection shaping gall wasp phenology, fecundity and persistence
Authors: SEIBERT T. F. 
Published: March 2008

Abstract.

The natural history of a gall wasp including interactions with inquilines, parasites, and a mutualistic ant are examined. The stability of the system is described from the perspective of influences on gall wasp life history characteristics.
An exclusion experiment demonstrated that the nectar‐secreting gall of Disholcaspis perniciosa mediates a mutualism with the tending ant, Formica obscuripes. Survivorship increased from 0% in the absence of ants to 25.3% in their presence, largely due to the exclusion of inquilines.
Specialized parasites, Eudecatoma spp., attacked before the ant‐gall interaction began, when the developing gall was still beneath the host plant (Quercus gambellii) epidermis and ants were not in attendance. They may select for later developing gall wasps, which benefit by having fewer individuals parasitized. However, counter‐selection for earlier development may result from decreased gall wasp size, decreased fecundity, and an increase in gall failures resulting from late development.
Local persistence of the gall wasp population despite increased pressure from inquilines and parasites was attributed to gall wasp escape in time due to polymorphic emergence resulting from diapause. Most individuals emerge at the end of the summer, but approximately 15% remain in the galls as prepupae for 1–5 years.
Fire ant predation on native and introduced subterranean termites in the laboratory: effect of high soldier number in Coptotermes formosanus
Authors: WELLS JEFFREY D. , HENDERSON GREGG 
Published: March 2008

Abstract.

Native Reticulitermes spp. Holmgren and the introduced Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) were exposed to predation in the laboratory by Solenopsis invicta Buren (Hymenoptera: Formicidae), a known predator of Reticulitermes.
In one experiment, both taxa contained the 2.4% soldiers commonly found in Reticulitermes. In a second experiment, Reticulitermes contained 2.4% and C.formosanus a more normal 18.3% soldiers.
When soldier proportions were equal, C.formosanus soldiers suffered less of a decrease in survivorship due to predation compared with Reticulitermes soldiers. Little difference was found between taxa in the effect of predation on termite workers or in the effect of termites on predator survivorship.
When soldier proportions were unequal, both C.formosanus castes suffered less from predation than those of Reticulitermes. Again, little difference was found in the effect of termites on ants.
C.formosanus showed less movement into new containers when soldier number was abnormally low, compared with both taxa with normal caste proportions.
Relationships between abundance and body size: where do tourists fit?
Authors: GASTON KEVIN J. , BLACKBURN TIM M. , HAMMOND PETER M. , STORK NIGEL E. 
Published: March 2008

Abstract.

The possible effects of the inclusion of ‘tourist’ species have been the cause of some concern in investigations of interspecific relationships between abundance and body size.
Data for adult beetles (Coleoptera) from oak trees in Britain are used to investigate the relationship of abundance to body size when tourists are and are not included.
For this particular assemblage, tourists do not fundamentally alter the basic statistics of the relationship between abundance and body size. However, they are not a random sample of the beetle assemblage. They have lower abundances and are also of smaller body size than other species.
Flower constancy and learning in foraging preferences of the green‐veined white butterfly Pleris napi
Authors: GOULSON D. , CORY J. S. 
Published: March 2008

Abstract.

Evolutionary pressure should select for efficient foraging strategies, within the constraints of other selective forces. We assess the mechanisms underlying flower choice in the butterfly, Pieris napi (L.), which as an adult forages for nectar. Experiments were carried out on a laboratory colony, using artificial flowers of two colours, and replicated on two successive generations.
When nectar was freely available from all flowers, equal numbers of butterflies visited each colour, but individual butterflies exhibited flower constancy, showing a strong preference for one colour or the other.
Following 3 day conditioning periods in which nectar was available from flowers of one colour only, butterflies responded by developing a preference for this colour, which persisted when both flower colours were refilled. This preference could subsequently be switched to the other flower colour following a further 3 days of conditioning. These are interpreted as adaptive (learned) responses, which would have obvious selective benefits in the field, enabling butterflies to avoid flower species which experience has shown are poor sources of nectar, and to adapt to temporal and spatial changes in nectar availability.
Gall aphids do not select optimal galling sites (Smynthurodes betae; Pemphigidae)
Authors: BURSTEIN MOSHE , WOOL DAVID 
Published: March 2008

Abstract. 1. In studies of insect‐host plant interaction it is often suggested that insects preferentially colonize host plants (or sites within plants) on which their fitness is maximized (a positive covariance of preference and performance). This suggestion stems from the assumption that natural selection has driven the system toward optimal use of resources.2. Our study of the galling aphid Smynthurodes betae Westw. demonstrates that the distribution of galls on leaves is not due to preference, and can be altered by manipulating the aphid arrival time or the shoot growth rate.3. We found no correlation between gall density and performance (aphid clone size) at different positions along the shoot.4. Because leaves on the growing shoot are not equally responsive to aphid stimulation, the colonizers have no choice but to settle on leaves that are at the right stage when they arrive.5. S.betae colonizers did not discriminate between shoots of their host and a congeneric non‐host, on which their fitness is invariably zero.6. Synchronization between galler and host plant phenologies seems to be the key to the observed distribution of galls on the tree. The data give no support to the preference‐performance hypothesis.
Long‐term dynamics of leaf miners,Eriocraniaspp., on mountain birch: alternate year fluctuations and interaction withEpirrita autumnata
Authors: BYLUND HELENA , TENOW OLLE 
Published: March 2008

Abstract.Abundance of leaf‐mining larvae of the outbreak speciesEriocraniaspp. was monitored in northern Sweden in 1955–67 and 1984–92 in a mountain birch forest rejuvenated by anEpirrita autumnataoutbreak in 1954–55.Eriocraniamine density fluctuated in a regular biennial pattern, probably due to a semivoltine life cycle. The alternate year fluctuations had shifted phase between the two study periods.The density fluctuated at a significantly higher mean level and with a lower amplitude in thec.10‐year‐old forest in the 1960s than in the 30‐year‐old forest in the 1980s. However, no difference was found in mine density betweenc.30‐ and >60‐year‐old stands in the 1980s.Significant correlations between the density of mines in high‐density years and date of budburst, and between rate of change between high‐density years and the time between snow‐melt and budburst indicate effects of weather. No correlation was found between yearly average mine density and date of budburst, precipitation or temperatures in May or June.No correlation was found between the mean densities ofEriocraniamines andE.autumnatacaterpillars in the same and the two preceding years. However, in the first (1955) and highest of three studiedE.autumnatapeaks a negative effect on population density ofEriocraniawas indicated.A significant, negative correlation between the number ofEriocraniamines andE.autumnatacaterpillars on single branches was found in three out of eighteen years. The separation of caterpillars and mines at branch level indicates an effect of avoidance at intermediate population densities.
The effect of a foliar disease (rust) on the development of Gastrophysa viridula (Coleoptera: Chrysomelidae)
Authors: HATCHER PAUL E. , PAUL NIGEL D. , AYRES PETER G. , WHITTAKER JOHN B. 
Published: March 2008

Abstract.

Gastrophysa viridula Degeer (Coleoptera: Chrysomelidae) and the pathogenic rust fungus Uromyces rumicis (Schum.) Wint. both occur on leaves of Rumex crispus L. and R.obtusifolius L. Individual stages of beetle development, and egg laying, were compared on healthy and infected leaves of each plant species in the laboratory. Oviposition choice was investigated in the field and laboratory.
Beetles reared on infected leaves of each species had greater larval mortality and slower development than those reared on healthy leaves. Although larvae feeding on infected leaves consumed up to 2.5 times more dry weight than those reared on healthy leaves, they had a lower relative growth rate and pupated at a lower weight. These changes were consistent with the reduced nutritive quality of rust‐infected Rumex leaves.
Fecundity of beetles reared on infected leaves of both species was considerably reduced. Eggs laid by beetles feeding on infected R.crispus leaves also had a reduced viability.
The beetle developed consistently poorer on healthy R.crispus than on healthy R.obtusifolius throughout its life‐cycle. Differences in larval performance were greater between host species than between infected and healthy leaves.
Oviposition was similar on infected and healthy R.crispus in both the laboratory and field. However, adults consumed less, and laid fewer eggs on infected than on healthy R.obtusifolius. The pattern of egg laying on different aged leaves was affected by rust infection: a greater proportion of eggs was laid on the older, infected leaves, than on the equivalent aged leaves on the healthy plants. Few larvae survived from eggs laid on rusted leaves in the field.
Spittlebug indicators of nitrogen‐fixing plants
Authors: THOMPSON VINTON 
Published: March 2008

Abstract.Spittlebugs (Homoptera: Cercopoidea) are preferentially associated with nitrogen‐fixing angiosperms. Generally, the Aphrophoridae associate with legumes, the Clastopteridae with actinorhizal plants, and the Cercopidae with associative nitrogen‐fixing grasses. This is the first reported insect—host association specific to nitrogen‐fixing plants.It is probable that spittlebugs are attracted to nitrogen‐fixing plants because these hosts provide a relatively rich, reliable source of organic nitrogen compounds for xylem‐sucking insects.Many spittlebugs live on plants that do not fix nitrogen, and ecological, mechanical or chemical factors may bar some spittlebugs from otherwise suitable nitrogen‐fixing plants.Among nitrogen‐fixing hosts, spittlebugs appear to prefer plants that transport fixed nitrogen as amino acids and amides to plants that transport fixed nitrogen as ureides.
Adult movements between populations in the specialist butterflyProclossiana eunomia(Lepidoptera, Nymphalidae)
Authors: BAGUETTE MICHEL , NÈVE GABRIEL 
Published: March 2008

Abstract.The structure of local populations of a monophagous butterfly, the bog fritillaryProclossiana eunomia, was studied in a complex of suitable habitat patches separated by spruce plantations or fertilized pasture.An unexpected high level of adult movements between habitat patches was detected by a mark—release—recapture technique. Local populations were connected by adult movements across unsuitable habitats, leading to a meta‐population structure.This evidence of the metapopulation structure of a specialist butterfly challenges the supposed relationship between habitat specialization and closed, isolated populations.Males and females ofP.eunomiaexhibited different spatial behaviours; females were more likely to emigrate and dispersed further than males. These differences in spatial behaviour are related to the mating system.
Performance of Symydobius americanus (Homoptera: Aphididae) on paper birch grazed by caterpillars
Authors: MARTIN MARC‐ANDRÉ , CAPPUCCINO NAOMI , DUCHARME DOMINIC 
Published: March 2008

Abstract.

The potential for host plant‐mediated interactions between leaf‐chewers and the aphid Symydobius americanus on paper birch (Betula papyrifera) was investigated experimentally.
Datana ministra and Malacosoma disstria caterpillars were caged on randomly chosen, undamaged branches until they had eaten 30–50% of the leaf area. Control branches received cages but no larvae.
Alates of S.americanus were than caged on the experimental and control branches to assess the effect of chewing damage on colony performance.
Chewing damage had no detectable effect on initiation of alate reproduction, development time, mortality of nymphs or colony growth rate.
The feeding behaviour of Carterocephalus palaemon (Lepidoptera: Hesperiidae) caterpillars: does it avoid host defences or maximize nutrient intake?
Authors: RAVENSCROFT N. O. M. 
Published: March 2008

Abstract.

The larvae of the chequered skipper butterfly Carterocephalus palaemon notch the blades of purple moor‐grass Molinia caerulea before feeding.
The nutrient concentrations above and below these notches were measured and the nutrient concentrations of undamaged blades of the host plant.
Nutrient concentrations above the notches remained similar to undamaged blades for a short period, whilst concentrations below declined, especially nitrogen, calcium and magnesium.
The feeding behaviour of C.palaemon larvae is discussed in relation to declining levels of nutrients in the food plant over the larval season and to other possible reasons for this behaviour, such as avoidance of host defences initiated in response to attack.