bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting foraging related behaviours in two sympatric wasps (Vespula maculifrons and V. germanica)
Authors: PARRISH M. D. , FOWLER H. G. 
Published: March 2008

ABSTRACT.

Using pinned freshly killed wasps (yellowjackets) to simulate feeding animals, it was found that V. germanica was socially facilitated, and concentrated its foraging activity on those feeders with the most pinned wasps (twenty). V. maculifrons foragers responded inversely, preferentially foraging at feeders with few or no pinned wasps.
Using hand‐painted drawing pins (thumb tacks) as wasp models, similar results were found, indicating that visual, rather than olfactory, cues were responsible for the observed distribution.
Vespula maculifrons and V. germanica exhibit aggression while foraging at honey‐baited feeders. Both species attack conspecifics at frequencies lower than would be expected under random encounter.
Seasonal colour changes, sexual maturation and oviposition in Psylla peregrina (Homoptera: Psylloidea)
Authors: SUTTON ROBIN D. 
Published: March 2008

ABSTRACT.

Colour change is shown to be related to the timing of sexual maturation of P.peregrina Förster. Males become sexually mature and attain their autumnal coloration about 3 weeks before females.
Upon maturation males migrate down branches into the inner crowns of hawthorn trees. Females show a similar movement as they mature later in the season.
Seasonal colour changes may serve cryptic functions and are appropriate to the different environments in which adults are found during the season.
The distribution of overwintering eggs reflects the post maturation distribution of adult psyllids, with eggs being concentrated on old wood towards the base of hawthorn branches.
Selection of plant parts by Depressaria multifidae (Lep., Oecophoridae) on its seasonally‐restricted hostplant, Lomatium grayi (Umbelliferae)
Authors: THOMPSON JOHN N. 
Published: March 2008

ABSTRACT.

Depressaria multifidae Clarke feeds on a broader variety of Umbelliferae plant parts than other Depressaria species.
Early instar larvae feed in the sheaths surrounding floral buds and leaves. Later instar larvae feed in the sheaths and floral stems and on flowers and leaves.
Floral stems bored by larvae had significantly larger basal stem diameters than floral stems that were not bored. Smaller stems usually have umbels with only male flowers, and wither after flowering, too soon for larvae to complete development. In contrast, larger stems often have umbels with some hermaphroditic flowers, which remain green and erect long enough for larvae to complete development. Hence, selection may favour larvae that bore only in relatively large stems.
In the laboratory, larvae fed sheaths with enclosed floral buds, flowers, or leaves all pupated at the same weight, but larvae fed floral stems pupated at a significantly lower weight. Larval and pupal development time was the same on all plant parts.
In the field, larvae restricted to a single umbel throughout development pupated at the same weight as those restricted to a single leaf.
Unlike in other Depressaria species, nitrogen levels only partly correspond to the pattern of use of plant parts in D.multifidae. Nitrogen values varied as follows: floral buds > immature leaves ≥ flowers > floral stalks > sheaths excluding floral buds or leaves.
The broad variety of plant parts used by D.multifidae may result partly from the problem of feeding on a small, seasonally restricted hostplant; the greater use of sheaths and floral stems than in other Depressaria species may result from selection for safety from parasites or predators.
The results for D.multifidae indicate that the way in which an insect feeds on a plant species can vary broadly even at a single site.
Annual respiration and production estimates for collembolan and psocopteran epiphyte herbivores on larch trees in southern England
Authors: TURNER B. D. 
Published: March 2008

ABSTRACT.

The population and biomass dynamics of the collembolan and psocopteran epiphyte herbivores on larch trees at Ranmore Common, Surrey, were followed from October 1976 to October 1978.
The effect of temperature and body weight on the metabolic rate of the epiphyte herbivores was determined in the laboratory.
The metabolic rate of Psocoptera appears little influenced by changes in temperature within the range they normally experience in the field. This‘low Q10 metabolism’is discussed in the light of other studies of species showing a similar phenomenon.
The collembolan metabolism also shows some temperature compensation.
The laboratory studies on metabolic rate are combined with field data to give annual respiration and production estimates.
The data from southern England are compared with published data from northern England sites and their differences discussed.
Seasonal biological variation in some leaf‐miner parasites in the genus Achrysocharoides (Hymenoptera, Eulophidae)
Authors: BRYAN GEORGINA 
Published: March 2008

ABSTRACT.

Most Achrysocharoides species and their Phyllonorycter hosts (Lepidoptera, Gracillariidae) have two generations per year in Britain.
In those species with separate sex broods, peak male emergence tends to be earlier than peak female emergence. This female emergence lag is shorter in the second generation.
The mean brood size in the second generation is significantly smaller than in the first in A.cilla males and females, A.latreilli females, mixed sex broods of A.atys, and A.carpini females. A.cilla, A.latreilli and A.niveipes generally have a significantly greater proportion of males in the second generation, but A.atys does not.
There is a shift to killing later instar Phyllonorycter larvae in the second generation, when a much higher percentage parasitism is generally achieved.
The intergeneration differences in sex ratio and brood size may be explained by a change in oviposition behaviour of females of the first and second generations.
The population biology of the Orange Tip butterfly Anthocharis cardamines in Britain
Authors: COURTNEY S. P. , DUGGAN A. E. 
Published: March 2008

ABSTRACT.

The population biology of Anthocharis cardamines (L.) is described and shown to vary with locality. Southern and Western populations emerge earlier than Northern ones, but Western and Northern populations occupy similar, wetter habitats and are associated primarily with Cardamine pratensis (L.). Southern populations are recorded mostly from Alliaria petiolata (Bieb.).
Studies on egg and larval survival indicate that host plant‐induced death and parasitization by a tachinid are important mortality factors. However, a key‐factor analysis on one population indicates that the major determinant of population size may be the number of eggs laid by ovipositing females, itself dependent upon weather during the oviposition period. Populations in different localities do show similar trends in abundance, corroborating the effect of weather.
Human effects on distribution and abundance are discussed, and some conservation strategies suggested.
Phenology and intensity of phyllophage attack on Fagus sylvatica in Wytham Woods, Oxford
Authors: PHILLIPSON J. , THOMPSON D. J. 
Published: March 2008

ABSTRACT.

Overwintering beech buds began to swell in early April and bud‐break occurred in early May. Most phyllophage attacks were initiated during the 21 day period of leaf growth but additional attacks occurred up to 46 days from bud break.
An average beech tree, with a top height of 24 m and a d.b.h. of 110 cm, bore 420 345 leaves (17% in the upper canopy, 27% in the upper middle canopy, 27% in the middle canopy, 18% in the lower middle canopy and 11% in the lower canopy).
Damage by phyllophages was greatest in the lower canopy; some 75—85% of the leaves were attacked in this stratum and damage amounted to 35% of the total phyllopage damage to the trees.
The major agents of damage in the lower canopy were adult P. argentatus, larval R. fagi and lepidopteran macrophages. Adult R. fagi concentrated their feeding in the upper canopy.
Allowing for damage expansion due to leaf growth the percentages of the total leaf area actually removed, or seriously damaged, by phyllophages were calculated to be 3.43–4.00% in 1978 and 2.37–2.74% in 1979.
Grasshopper populations and weather: the effects of insolation on Chorthippus brunneus
Authors: BEGON MICHAEL 
Published: March 2008

ABSTRACT.

In nature, the internal body temperature of Chorthippus brunneus Thunberg is found to be raised substantially under the influence of direct insolation.
In the laboratory, similarly raised body temperatures, resulting from the radiant heat of a light bulb, lead to a 5.6‐fold increase in the rate of development, and a similar or even higher increase in the rate of adult maturation. The rate of egg‐production is even more greatly affected, being negligible in the absence of a radiant‐heat source.
These physiological results provide an explanation for the frequently found correlation between grasshopper abundance and hot and/or dry weather.
The results are also discussed in terms of the problems they pose for the derivation of a physiological time‐scale for basking insects, and the evolutionary forces and constraints that might give rise to them.
Seasonal shifts in host usage in Uroleucon gravicorne (Homoptera: Aphididae) and implications for the evolution of host alternation in aphids
Authors: MORAN NANCY A. 
Published: March 2008

ABSTRACT.

Uroleucon gravicome (Patch) feeds on annual Erigeron species and on perennial Solidago species.
To test whether Solidago and Erigeron are analogous to winter and summer hosts of typical host‐alternating aphids, reproductive performance, host preferences, and host associations were measured for E.strigosus, S.juncea and S.nemoralis during spring, summer and autumn.
Caged individuals can reproduce on both genera throughout the season, though colonies are rare on Solidago during summer.
Developmental rate, adult weight, and fecundity decline between May and August on all hosts; however, the drop is least on E.strigosus, intermediate on S.nemoralis, and greatest on S.juncea.
Throughout the season, reproductive performance is at least as great on Erigeron as on Solidago, the difference being least in spring.
Soluble nitrogen content shows the same seasonal trends as reproductive performance, declining in all hosts, but declining least in E.strigosus.
Preference tests and field records show that U.gravicorne moves from Solidago to Erigeron when the first alatae mature in late spring, feeds on Erigeron during the summer, and, in late summer, returns to Solidago where overwintering eggs are laid.
Solidago is not nutritionally superior during spring or autumn; its use during those seasons may result from the need for good oviposition sites.
The natural history of a phoretic sphaerocerid Diptera fauna
Authors: SIVINSKI JOHN 
Published: March 2008

ABSTRACT.

Three species of phoretic Sphaeroceridae kleptoparasitize the dung caches of scarab beetles in north Florida. Ceroptera sivinskii Marshall intercepts beetles under dung, then accompanies them into their burrows. Borborillus frigipennis (Spuler) rides on ball rolling and tunnelling scarabs. It perches on beetles both underground and in flight. B.singularis (Spuler) is similar in habits but is principally nocturnal.
Kleptoparasitism is probably a means of escaping environmental decay and competition in‘parent’faeces. Nonscarab competitors and predators are less abundant in beetle stored dung, and Borborillus spp. are among the few spaerocerids that flourish when large, rapidly developing calypterate flies are abundant.
Since oviposition in B.frigipennis occurs only underground, phoresy is an inexpensive and safe means to maintain contact with hosts. Males ride in order to find mates.
The ecology and status of Thymelicus acteon (Lepidoptera: Hesperiidae) in Britain
Authors: THOMAS J. A. 
Published: March 2008

ABSTRACT.

A survey was made of the local butterfly, the Lulworth Skipper (Thymelicus acteon Rott.) in Britain. Adult numbers were estimated on most sites and the habitat was analysed. Changes in numbers were also recorded in five populations over 6 years, and some aspects of behaviour were studied.
T.acteon forms closed populations. It was found in great abundance throughout its historical range, and appears both to have increased in numbers and to have spread locally. It has not extended its range.
The wrong larval foodplant is quoted by some modern textbooks. T.acteon requires mature Brachypodium pinnatum Beauv. plants for breeding. Within its range, the butterfly was almost ubiquitous in areas with tall Brachypodium.
The present abundance and probable increase of T.acteon is attributed to the spread of B.pinnaturn in unimproved calcareous grassland. This has occurred through a decline in grazing, both by domestic stock and, since myxomatosis, by rabbits.
Energy partitioning in the Antarctic collembolan Cryptopygus antarcticus
Authors: BURN A. J. 
Published: March 2008

Abstract. 1. Consumption, production and assimilation rates were determined for two age groups of Crypropygus antarcticus to give an estimate of energy utilization, and to investigate low temperature adaptation in its energy partitioning.2. Feeding selectivity shown in laboratory preference tests was supported by gut analysis of field animals from contrasting sites. Although moulting rate was not significantly affected by food type, rates of growth were slowest and mortality highest when fed on a non‐preferred substrate.3. Both a radio labelling and a more direct method for measuring dry weight consumed gave similar results for Cvpropygus feeding on algae. The consuniption rate for animals when feeding on algae was lower than that on moss peat. The assimilation efficiency for immature animals feeding on algae was 46% and for mature animals was 19%; the values when feeding on moss peat were 7% and lo%, respectively, The net production efficiency ranged from 35%(inimatures) to 13% (matures) and was similar on both substrates.4. Food consumption exceeded assimilation over the range 2.5–10°C, but the two converged from 2.5 to 0°C. Immature Cryptopygus maintained a net positive energy balance over 0–10°C, whilst below 1S°C respiration exceeded assimilation for mature individuals.5. An estimate of the annual dry matter consumption (7 g m‐1 y‐1) by Ctypropygus in a moss turf at Signy Island agrees with one based on respiration data alone (Davis, 1981). The consumption at an alga‐dominated site was c. 26 g m‐2 y‐l, and Crypropygus may have a locally limiting effect on net priniary production at such sites.
Mixed function oxidases and herbivore polyphagy: the devil's advocate position
Authors: COULD F. 
Published: March 2008

Abstract. 1. Evidence used to support the theory that mixed function oxidases (MFOs) are important in the survival of polyphagous herbivores is briefly reviewed. This evidence includes data on patterns of variation in MFO activity among species and among developmental stages within species. It also includes data on induction of MFO activity by plant compounds and metabolism of plant cornpounds by MFOs.2. It is argued that the evidence presently available does not offer strong support of the theory because key pieces of information are lacking. Evidence which tends to refute the theory is reviewed and discussed.3. Experiments are proposed which could more rigorously test the theory.
Effects of cyanogenesis in bracken fern (Pteridium aquilinum) on associated insects
Authors: SCHREINER ILSE , NAFUS DONALD , PIMENTEL DAVID 
Published: March 2008

Abstract. 1. The relationship between cyanogenesis in bracken fern and the insect fauna feeding on the plant was investigated over a 3 year period. The most common insects between May and July, while cyanide levels were high, were the sawflies Strongylogaster impressata Provancher, S.multicincta Norton, Aneug‐menus fzavipes (Norton), the aphid Macrosiphum euphorbiae (Thomas) and a microlepidopteran species of Monochroa.2. Collections of insects from cyanogenic and acyanogenic fronds showed significantly fewer sawflies on the cyanogenic fronds. The aphid and the microlepidopteran were randomly distributed with respect to cyanogenicity.3. Feeding tests for two of the sawfly species (Simpressata and Smulticincta) showed that larvae grew more slowly and had a higher mortality when raised on cyanogenic fronds than on acyanogenic ones.4. Field collected cyanogenic bracken fronds were found to have sustained less damage from chewing herbivores compared with acyanogenic fronds.
Food competition among Scotophugu stercoraria Iarvae with emphasis on its effects on reproductive success
Authors: SIGURJÓNSDÓTTIR HREFNA 
Published: March 2008

Abstract. 1. Laboratory experiments with yellow dung fly larvae, Scatophaga sfercoraria L. were carried out in the hope of clarifying the causal relationship underlying the extreme variation in body size in wild populations.2. First, parents were collected in the field and newly hatched larvae exposed to different density levels under two temperature regimes (15°C and 20°C). Second, heritability experiments were done.3. The results showed that density during the larval stage has a very significant effect on adult size. Male size is more affected than female size and the male larvae spend more time feeding than the female larvae with the result that the males are on average larger. Also, the additive genetic component is of little or no significance, supporting the notion that body size is positively related to fitness.4. Finally, the results are discussed in relation to field data on the effects of size on both male and female reproductive success.
Limitation of superparasitism by Aphidius rhopalosiphi: a consequence of aphid defensive behaviour
Authors: GARDNER SARAH M. , WARD S. A. , DIXON A. F. G. 
Published: March 2008

Abstract. 1. The behavioural mechanisms limiting superparasitism by Aphidius rhopalosiphi (DeStefani‐Perez) are described.2. A.rhopalosiphi did not discriminate between parasitized and unparasitized aphids, or avoid attacking and ovipositing in previously parasitized aphids.3. Aphid defensive behaviour was increased for a short period after a parasite stabbing attack. In response to this behaviour the number of parasite stabbing attacks subsequently undertaken declined.4. Once a stabbing attack had been initiated, parasite oviposition success was unaffected by aphid defensive behaviour.5. It is concluded that applied defensive behaviour, by limiting the number of stabbing attacks undertaken by A.rhopalusiphi, effectively limits the number of parasite eggs laid and the extent to which super parasitism occurs.
Patterns in the distribution of leaf‐miners on British trees
Authors: GODFRAY H. C. J. 
Published: March 2008

Abstract. 1. A multiple regression analysis of the leaf miners on British native angiosperm tree genera was performed using measures of plant range, maximum height, taxonomic isolation and species per genus as independent variables.2. 69% of the variation was explained by regression.3. Taxonomic isolation was the most important variable with species per genus also having a significant effect. Plant range had no demonstrable effect.4. The analysis was repeated with component taxonomic groups of leaf miners. Up to 85% of the variation was explained.
Field studies of foraging behaviour of an intertidal beetle
Authors: RICHARDS LAURA J. 
Published: March 2008

Abstract. 1. Adult staphylinid beetles Thinopinus pictus LeC. are noct turnal predators of sand beach amphipods, Orchestoidea califomiana (Brandt). I made continuous observations of Thinopinus near the drift patches on which amphipods feed.2. Thinopinus alternated between active and ambush foraging modes.3. Thinopinus had greater attack rates and captured smaller amphipods while in active foraging mode.4. Thinopinus attacked 0.147 amphipods/min, and captured 9.1% of the amphipods attacked. The attack rate on amphipods increased with the proportion of time spent by Thinopinus in active mode.5. Thinopinus remained longer near types of drift patches which were more attractive to amphipods.
Species packing and temperature dependent competition among burying beetles (Silphidae, Nicrophorus)
Authors: WILSON DAVID SLOAN , KNOLLENBERG W. G. , FUDGE J. 
Published: March 2008

Abstract. 1. Burying beetles are carrion feeders that specialize on small carcasses. We investigated interactions among congeners at two sites in Michigan, U.S.A., that differ in both number and relative proportion of species.2. Intra‐ and interspecific competition for carcasses is intense. The majority of carcasses are found within 24 h of their placement.3. Competition between N.arbicollis and N.defodiens is temperature dependent. N.orbicollis can displace N.defodiens on single carcasses, but requires warm temperatures to find the carcasses. Cool weather therefore serves as a refuge for N.defadiens.4. The southern edge of N.defodien's geographical range is probably determined by competition with N.orbicollis.5. N.sayi and N.tomenrosus are spring and autumn breeders respectively, and rarely interact with each other or the other two species. Nevertheless, interspecific competition is the most likely evolutionary force leading to seasonal segregation.
Diapause in a large aggregation of a tropical beetle
Authors: WOLDA HENK , DENLINGER DAVID L. 
Published: March 2008

Abstract. 1˜ Diapause is described for adults of Stenotarsus rotundus Arrow (Endomychidae, Coleoptera) in the tropical lowland forest on Barro Colorado Island, Panama.2. Diapause lasted up to 10 months each year, covering some 6 months of the wet season plus 4 months of the dry season. When in diapause the beetles clustered in an aggregation of up to 70,000 individuals on the stem of a palm tree, the same individual palm tree in at least four successive years.3. The habitat and habits of the beetle when not in diapause are unknown, but one or two generations may be produced during this period. Beetles returned to the diapause site from June until late August.4. Soon after arrival at the diapause site the flight muscles degenerated and did not develop again until February/March. The ovaries were undeveloped when the beetles arrived at the site and remained in that condition until the onset of yolk deposition in March. At the beginning of the rainy season in April the beetles mated and dispersed.5. Lean dry weight of the beetles did not decrease noticeably during diapause, but fat content did. It is suggested that the beetles do not feed, or feed very little, while in diapause. During diapause, the metabolic rate is surprisingly low considering a mean ambient temperature of 25° C.6. Juvenile hormone analogue (ZR515) stimulated flight muscle and ovary development. Daylength, when different from LD 12:12, initiated a partial flight muscle development, but there was no effect on the ovaries. Field observations suggest that neither temperature nor humidity had an effect on the termination of diapause.7. Although the development of both flight muscles and ovaries were stimulated by juvenile hormone analogue and both developed around March of each year, it is suggested that the mechanisms causing this development are different.
Responses of leaf miners to atypical leaf production patterns
Authors: AUERBACH MICHAEL , SIMBERLOFF DANIEL 
Published: March 2008

Abstract. 1. Larvae of two bivoltine species of leaf‐mining Lepidop‐tera, Acrocercops sp. and Neurobathra strigifinitella (Clem.), restrict feeding to young, second‐flush leaves of their host trees in north Florida.2. During 1980 and 1981, densities of both species varied greatly among thirty small water oaks (Quercus nigra), as did timing and extent of secondary leaf production.3. In both years leaf‐miner density at the end of the first generation (mid‐August) was positively correlated with secondary leaf production.4. Five trees abscised their leaves and reflushed new ones at atypical times of the growing season. When refoliation coincided with emergence of ovipositing adults, Acrocercops sp. and N.strigifinitella densities increased dramatically, indicating that both species are at times limited by availability of young leaves.5. By staggering termination of diapause these leaf miners can exploit a temporally variable resource.