bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host plant specificity, oviposition behaviour and egg parasitism in some leafhoppers of the genus Eupteryx (Hemiptera: Cicadellidae)
Authors: STILING PETER D. 
Published: March 2008

Abstract.

Three species of Eupteryx, E.aurata, E.cyclops and E.urticae are regularly found on stinging nettles in South Wales.
E.aurata host alternates between nettles in spring and autumn, and Heraclewn, Eupatorium and Mentha species in summer. E.cyclops and E.urticae attack only nettles.
All species are host specific during oviposition and show preferences to lay eggs in discrete plant regions.
A Mymarid egg parasite of the genus Anagrus was reared more commonly from eggs laid in nettles than from eggs laid in alternative hosts.
Density‐dependent changes in sex ratio in Colias lesbia (Lepidoptera: Pieridae)
Authors: BERNSTEIN CARLOS 
Published: March 2008

Abstract.

The changes in sex ratio of a population of Colias lesbia were studied for four consecutive years.
A constant sex ratio was found in the samples taken in the 34 days following the last harvest of the alfalfa.
For the samples taken 35 or more days after the harvest the sex ratio decreases as the total number of adults caught increases.
The indirect evidence collected suggests that differences in emigration tendencies between sexes play a major role in determining the sex ratio in this species.
Invertebrate predation of leaf‐miners at low densities
Authors: FAETH STANLEY H. 
Published: March 2008

Abstract.

Predation on a species of leaf‐mining insect, Eriocraniella sp., by two species of ants, Crematogaster ashmeadii Mayr and Pseudomyrmex brunnea F. Smith, is documented.
Exclusion experiments show that ants and other terrestrial invertebrates can greatly contribute to mortality of leaf‐miners and significantly decrease survivorship of the larval stages even when densities are low.
Comparison of two leaf‐mining species, Eriocraniella sp. and Cameraria sp. nov. Davis, indicates that factors of mortality depend on the maturity of the leaf being mined.
Ecological studies on the parasite complex associated with typhlocybine leafhoppers (Homoptera, Cicadellidae)
Authors: JERVIS MARK A. 
Published: March 2008

Abstract.

The parasite complex associated with nymphal and adult typhlocybine leafhoppers consists of the following: Dryinidae (Aphelopus species), Pipunculidae (Chalarus species) and Diapriidae (Ismarus dorsiger Curtis), the last being parasitic on species of Aphelopus.
The life cycles and temporal distribution patterns of twenty‐nine species of Typhlocybinae are summarized together with the life cycles of British Aphelopus and Chalarus.
Closely related primary parasite species differ in their adult emergence times. Species differences in adult emergence times of diapausing Chalarus are correlated with species differences in host relations.
Each primary parasite genus contains both monophagous and polyphagous species. Each polyphagous species shows a distinct ‘preference’ for a particular range of hosts.
The parasite complexes of different leafhopper communities are compared, and it is concluded that it is the taxonomic composition of the leafhopper communities which is chiefly responsible for the structure and taxonomic composition of their associated parasite complexes.
Individual species of both Aphelopus and Chalarus show a degree of sensitivity to the physiology of their hosts, so achieving a high degree of synchrony.
Life budgets for a population of Tipula sacra (Diptera; Tipulidae)
Authors: PRITCHARD GORDON 
Published: March 2008

Abstract.

A population of Tipula sacra was studied intensively from 1969 to 1974 in a series of abandoned beaver ponds. Beavers recolonized the ponds from 1974 to 1976 and again in 1978.
The basic life‐cycle is of 2 years duration, but cohort‐splitting occurs in the autumn as a result of some larvae growing faster and completing the life‐cycle in 1 year.
Some periods are more favourable for growth than others and the size of the fast‐growing cohort varies from year to year. This insight allows some anomalies in the estimates of population size to be explained and life budgets have been produced for three year‐classes.
The short‐fall in realization of egg potential is massive, apparently due to heavy female mortality by predation and the prevention of oviposition by inclement weather.
Mortality rate is relatively low and constant from stage II larvae until pupation, but increases to adult emergence. There is a correlation between larval density and mortality rate.
Certain aspects of the life‐history (e.g. high fecundity, variability in growth rate) appear to fit the species to life in a temporally unstable habitat.
Another look at prey detection by coccinellids
Authors: STUBBS MARY 
Published: March 2008

Abstract.

Adult and fourth instar larvae of Coccinella septempunctata (L.) were tested to see whether or not they could detect prey prior to physical contact.
Adult predators found aphid prey and a silver foil dummy significantly faster than an X‐mark on the floor of the arena covering the same area.
Fourth instar larvae found crushed prey more quickly than the X‐mark but were not able to detect whole frozen prey.
The distances at which the predators could detect prey were calculated. This distance was found to be about 1.0 cm for the adults and 0.7 cm for the fourth instar larvae.
Taxonomic isolation and the accumulation of herbivorous insects: a comparison of introduced and native trees
Authors: CONNOR EDWARD F. , FAETH STANLEY H. , SIMBERLOFF DANIEL , OPLER PAUL A. 
Published: March 2008

Abstract.

Evidence from leaf‐mining insects on Fagaceous hosts suggests that range expansions of insects onto introduced trees often involve species that feed on native hosts closely related to the introduced host.
An examination of the herbivorous entomofauna of British trees illustrates that the size of the entomofauna is partially determined by the taxonomic isolation of the host tree.
Adaptive dispersal and appetitive flight in the green lacewing, Chrysopa cornea
Authors: DUELLI PETER 
Published: March 2008

Abstract.

The flight behaviour of Chrysopa cornea Steph. (Neuroptera: Chrysopidae) with regard to dispersal activity has been investigated in field experiments. There are three main types of flight activities.
Shortly after emergence (in the first two nights) the adults perform adaptive dispersal flights which are straight downwind flights mostly at elevations higher than 3 m above ground. The lacewings do not react to the presence of honey dew in the crop.
After 2—3 days the scent of honeydew becomes a strong landing stimulus. The flight is now an appetitive downwind flight which usually is lower than 3 m above ground.
Once landed, the lacewings' subsequent flights are toward the source of the kairomone which signals honeydew. This can be termed appetitive upwind flight. It is a low stepwise flight within the ‘boundary layer’ which rarely exceeds 1 m above crop level.
Dispersal takes place in a continuous ‘rolling’ downwind movement of the whole lacewing population. The immigration rate into a field is thus not a function of the quality of that field but rather of upwind fields. Emigration, however, strongly depends on the presence of honeydew (retaining of ovipositing immigrants) and the density of aphids or other food for the larvae (production of new adults).
Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. I. Apion curtirostre Germ, and Rumex acetosa L.
Authors: HOPKINS M. J. G. , WHITTAKER J. B. 
Published: March 2008

Abstract.

Apion curtirostre is the commonest weevil attacking Rumex acetosa in the Lancaster area.
The ovipositional behaviour, larval development, emergence and hibernation of A. curtirostre are described.
From dissection of samples of stems of R. acetosa, abundance curves for the stages of A. curtirostre and its chalcid parasitoids were constructed and the between‐stage mortalities determined.
There is an exponential relationship between R. acetosa stem height and number of A. curtirostre eggs laid.
Male stems of R. acetosa appear earlier and are smaller than female stems. Taller stems, at least in female plants, live longer than shorter ones.
Apion survival is lower in male than in female stems.
Stem sex is the primary determinant of opposition choice with stem thickness a secondary determinant.
A. curtirostre eggs introduced experimentally into stems of four Rumex species survived significiantly better in R. acetosa than in any other species. Survival in R. acetosa female plants was twice that in males.
Survival of A. curtirostre eggs at densities of 4, 8 and 16 per R. acetosa stem was twice that at densities of 32 and 64 per stem.
The stem size of female R. acetosa was reduced as the number of attacking weevils increased. There was no significant effect in males. No adverse effect on seed production was detected.
The nature of the relationship between A. curtirostre and R. acetosa is discussed.
Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. II. Apion violaceum Kirby and Rumex obtusifolius L.
Authors: HOPKINS M. J. G. , WHITTAKER J. B. 
Published: March 2008

Abstract.

The biology of Apion violaceum is described, particularly with respect to its primary host, Rumex obtusifolius.
Oviposition in Rumex acetosa is directly into the stem, but in R. obtusifolius it takes place through the sheath enclosing developing flowers, stem leaves and stem.
Larvae cannot complete development in the leaf petioles and must migrate downwards to the stem or die before pupation.
Mortality of A. violaceum in the stems was highest in eggs and first instar larvae and in third instar larvae. The latter mortality was caused almost entirely by parasitoids.
Stems of R. obtusifolius on the study site increased in number up to August and reached the maximum height in late June.
Over the 4 year study period there was a parallel decline in stem numbers and mean stem height at two of the sites studied. At these sites there was also a decline in A. violaceum numbers and density per stem.
The quality of sites for A. violaceum, as defined by the product of stem numbers and stem height, showed a significant correlation with A. violaceum numbers.
Recapture studies of the harvester ant, Pogonomyrmex owyheei Cole, using a fluorescent marking technique
Authors: PORTER SANFORD D. , JORGENSEN CLIVE D. 
Published: March 2008

Abstract.

Mark—recapture sampling must be stratified because populations of foragers and defenders are partitioned by trunk trails and order of emergence respectively.
Foragers and defenders form overlapping subsets of the total colony population, each of which is correlated with total colony population size.
Foragers and defenders have an average life expectancy of approximately 2 weeks.
The fluorescent marking procedure did not significantly affect harvester ant mortality and only temporarily affected their behaviour.
Combinations and mixtures of fluorescent ink allow at least eight groups in a colony to be distinctly marked for periods exceeding 4 months.
The life history of Philanisus plebeius Walker (Trichoptera: Chathamiidae), a caddisfly whose eggs were found in a starfish
Authors: WINTERBOURN M. J. , ANDERSON N. H. 
Published: March 2008

Abstract.

Philanisus plebeius had a univoltine life cycle with adults present from November to April in the South Island of New Zealand. Males predominated in light trap collections in all months and the mean size of adult insects declined over the flight period.
There are probably seven larval instars which inhabited the marine intertidal zone and fed primarily on non‐calcareous algae. Pupae were found only on the red alga, Corallina officinalis.
Caddisfly eggs were found during most of the year in the coelom of an intertidal starfish, Patiriella regularis. Oviposition is probably through the popular pores and newly hatched larvae may leave the host via the same route or through the stomach wall.
Egg development time was greater than 30 days at 16–18°C.
P.plebeius probably colonized New Zealand from Australia after the unusual oviposition behaviour had evolved in association with the Australian cushion star, Patiriella exigua. P.regularis is less abundant and occurs lower on the shore than P.exigua and may be inaccessible to some caddisflies which oviposit amongst intertidal algae.
The relation between body size and resistance to desiccation in two species of Zaprionus (Drosophilidae)
Authors: BARKER JOHN F. , BARKER ANTJE 
Published: March 2008

Abstract.

Resistance to desiccation and body size were studied in the drosophilid flies Zaprionus vittiger and Z.tuberculatus.
Populations in a hot dry low altitude area were compared with those in a nearby cooler wetter high altitude area in the north‐eastern Transvaal of South Africa, using laboratory strains established from these populations.
No between‐area differences were found for either body size or resistance to desiccation considered separately.
However, in Z.tuberculatus, regression analyses using strain mean values showed a strong positive correlation between the two characters amongst strains derived from low altitude populations but not amongst strains derived from high altitude populations.
It is concluded that differences of genetic organization have evolved between low and high altitude populations of Z.tuberculutus.
From differences between species and sexes it is concluded that both body size and some unknown factor related to sex may influence resistance of desiccation.
The reproductive biology and diapause of the British fungal‐breeding Drosophila
Authors: CHARLESWORTH PAUL , SHORROCKS BRYAN 
Published: March 2008

Abstract.

Seasonal reproductive development was investigated in four obligate fungivorous species, D.phalerata Meigen, D.transversa Fallen, D.cameraria Haliday and D.confusa Staeger.
Samples of females taken from woodlands over a 2 year period were scored for reproductive status and fat content.
Populations of D.phalerata and D.cameraria maintained in an outdoor insectary provided information on developmental time and adult mortality throughout the year.
Experiments in controlled environmental chambers gave percentage diapause curves against day length for all four species.
In D.phalerata the influence of temperature and fungus upon diapause behaviour was also investigated.
In D.phalerata the optimal strategy for reproductive development can vary from month to month. Maturation of females may be immediate, dependent upon a fungal cue or completely prevented.
Susceptibility of Scaevola taccada (Gaertn.) Roxb. bushes to attack by the coccid Icerya seychellarum Westwood: the effects of leaf loss
Authors: HILL M. G. 
Published: March 2008

Abstract.

The distribution of infestation levels of the coccid Iceryu seychellarum on bushes of Scuevola taccudu and its population fluctuations over a 10 month period on Aldabra atoll show that individual plants of S. taccada exhibit differential susceptibility to attack.
Coccids on heavily and lightly infested bushes show no important differences in growth rate, fecundity or plant induced death rate. There were also no demonstrable differences in bush exposure, food quality (total and soluble nitrogen levels) or settlement behaviour of first instar larvae (crawlers).
Detailed examination of Iceryu populations on individual leaf clusters showed that mortality caused by leaf fall is density dependent and can be avoided only if a large proportion of the population frequently moves from senescing to mature leaves. The proportion of the population required to move to younger leaves in order to complete development is greater in low density Zceryu populations.
The effects of leaf fall are discussed with reference to the maintenance of differential susceptibility within the plant population.
Foraging patterns in three sympatric forest ant species, Prenolepis imparis, Paratrechina melanderi and Aphaenogaster rudis (Hymenoptera: Formicidae)
Authors: LYNCH JAMES F. , BALINSKY EDWARD C. , VAIL STEPHEN G. 
Published: March 2008

Abstract.

Ecological segregation was studied in Aphaenogaster rudis Emery, Paratrechina melanderi (Wheeler) and Prenolepis imparis (Say), the three commonest surface‐foraging ants in a Maryland (U.S.A.) hardwood forest community.
P.imparis retreats from the surface during mid‐summer, but shows more cool‐season activity than do the other two species. P.melanderi is most active during the warmest months of the years. A.rudis is the most generalized of the three species in its seasonal activity pattern.
P.imparis is a highly aggressive species which forms large mobilizations at rich food sources. P.melanderi is a timid species which forms small mobilizations. A.rudis is intermediate in both respects.
Based on the results of baiting trials, P.imparis shows an apparent preference for protein‐fat food, P.melanderi prefers carbohydrate food, and A.rudis exhibits no significant preference for either fclod type.
As a result of its extended seasonal activity, weak circadian periodicity, and lack of food specialization, A.rudis has the broadest annual niche of the three species studied.
The unusual seasonal activity pattern of P.imparis results in a relatively low degree of annual niche overlap between this species and either of the other two. Overlap between A.rudis and P.melanderi is substantially higher.
Experimental manipulations confirm that rates of resource removal by a behaviourally subordinate species (Amdis) are reduced in the presence of a dominant species (P.imparis).
Persistence of these three widespread, abundant, relatively generalized ant species in local sympatry may in part reflect their differential success in: (a) finding food, (b) defending food, and (c) handling food items of different sizes.
Latin Square designs in field experiments involving insect sex attractants
Authors: PERRY J. N. , WALL C. , GREENWAY A. R. 
Published: March 2008

Abstract.Interactions between insect sex attractant traps are of ecological interest in themselves, but may cause problems in field experiments in which attractants, or control measures, are compared quantitatively.Some of these problems are solved by experimental designs based on the Latin Square.The applicability of the designs to research involving comparison of attractants, effectiveness of control measures and attractant trap interactions is discussed, and examples are given with field data.Efficiencies of different designs are compared using data from fifteen experiments.Disadvantages and extensions of the design are discussed.Latin Square designs are simple, practical, and usually more efficient than other designs.
Coexistence of two species of Binella Motchulsky (Coleoptera: Ptiliidae) and the significance of their adaptation to different temperature ranges
Authors: TAYLOR VICTORIA A. 
Published: March 2008

Abstract.

Ptinella aptera and Ptinella errabunda often coexist where their distributions overlap.
The ecological requirements of P.aptera and P.errabunda are similar. Both are generalized mycetophages restricted to the same subcortical habitat of trees in a particular state of decay. Relative humidity appears important in determining habitat suitability for both species, neither of which survived in laboratory regimes below approximately 100% relative humidity.
In laboratory studies the beetles differed in their response to temperature. Recorded maxima for activity and rate of increase were at higher temperatures for P.aptera than for Perrabunda.
Temperatures which ‘Ptinella were exposed to in the laboratory occur in natural conditions under bark. Their effects on the species’ distributions are considered.
The differential temperature adaptations of P.aptera and P.errabunda were probably evolved in allopatry, in response to different environmental conditions. In view of this, it is unreasonable to infer past interspecies competition from these niche differences.
The niche difference between coexisting Ptinella species is discussed in the light of current ideas concerning the relative importance of competition and other factors in natural communities.
Cohort studies on mosquito (Diptera: Culicidae) larvae living in the water‐filled floral bracts of Heliconia aurea (Zingiberales: Musaceae)
Authors: SEIFERT RICHARD P. , ROBERTO BARRERA R. 
Published: March 2008

Abstract. 1. An experimental and observational study of the three species of mosquito larvae living in the water‐filled floral bracts of Heliconia aurea at Rancho Grande, Venezuela, was designed to determine if each mosquito species forms instar cohorts and excludes conspecifics of younger instars. This study was motivated by a statement of Maguire (1971) who suggested that mosquito larvae in Puerto Rican Heliconia inflorescences form instar cohorts and exclude younger mosquitoes from the floral bracts.2. Field observations of naturally occurring populations of mosquito larvae from fifty‐three H.aurea inflorescences give no indication that cohorts are formed for Wyeomyia felicia and Culex bihaicolus. However, there is strong evidence that cohorts of Trichoprosopon digitatum occur. These cohorts are not structured by larval competition but by female preference of the youngest bracts as oviposition sites and by large T.digitatum larvae feeding on smaller con‐specifics.3. Field experiments show that first instar W.felicia and C.bihaicolus survive as well over a 6 day period in the presence of third instar conspecifics as they do when all mosquito larvae in an experimental bract are first instars.
Effects of host needle age on the settling behaviour of two morphs of Adelges cooleyi (Gill.)
Authors: SPIRES S. 
Published: March 2008

Abstract. 1. On Douglas fir progredientes of A.cooleyi migrate onto current‐year needles whereas the later‐hatching sistentes settle on older needles. The behaviour of these two morphs was compared in the laboratory.2. The track length of progredientes was slightly greater than that of sistentes, but the tracks of the two morphs did not differ in terms of degree of irregularity or linear displacement.3. Progredientes preferred current‐year needles whereas sistentes preferred previous‐year needles, especially on young branches.4. Probing by sistentes was strongly inhibited on young current‐year needles.5. This appears to be the first report in which two morphs of a single insect species on one host species prefer foliage of different ages.
Host plant associations, diversity and species—area relationships of mesophyll‐feeding leafhoppers of trees and shrubs in Britain
Authors: CLARIDGE M. F. , WILSON M. R. 
Published: March 2008

Abstract. 1. Sixty‐two British species of Typhlocybine leafhoppers are known to feed on the leaf‐mesophyll tissue of trees and shrubs. British host records for fifty‐five of these are given.2. The leafhopper faunas of thirty‐six species of native and introduced trees and shrubs are described.3. The Shannon‐Wiener equation was used to calculate species diversity for adult samples collected from twenty different species at sixteen different localities in Wales, southern England and northern Scotland.4. Sørensen's coefficients were calculated for rearing data from Britain generally, and subjected to cluster analysis. Most trees have low similarities with respect to leafhopper faunas and are quite distinct. Taxonomic relationships of trees appear to be relatively unimportant in determining the similarities of their leaf‐hopper faunas.5. Using the same data, species—area relationships were calculated for thirty‐four different tree and shrub species and their associated leaf‐hoppers. A significant regression was obtained, but it explained only 16% of the variation. It is thus suggested that host plant range is relatively unimportant in determining the numbers of these species associated with different trees in Britain.6. Some introduced species of trees, particularly the recently planted Nothofagus, have acquired large leafhopper faunas.