bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patterns of nest provisioning and parental investment in the solitary digger wasp Ammophila sabulosa
Authors: FIELD JEREMY 
Published: March 2008

Abstract.

In nest‐building wasps there is a continuum from species that provision each offspring cell with one large prey item (single provisioning) to species that provision each cell with many small items (multiple provisioning). The significance of number of prey per cell was examined during two seasons in Ammophila sabulosa (L.), a species that provisions between one and five caterpillars per cell.
There was no difference between the total weight of prey in singly‐provisioned and multiply‐provisioned cells: individual caterpillars placed in multiply‐provisioned cells were smaller.
Small caterpillars were captured and transported to the nest faster than large ones.
If the first prey provisioned was large, the cell was usually then permanently closed. If the first prey was small, additional prey were captured, and females appeared to become more selective: additional prey were rarely large.
It is suggested that the flexible provisioning strategy used by A.sabulosa allows a wide range of prey sizes to be utilized without affecting maternal control of offspring size and sex. This could be important when available prey sizes vary temporally and spatially.
There was a male‐biased first generation investment ratio. Female‐producing cells were provisioned with a higher total prey weight than male‐producing cells, and conversion of prey weight to adult weight was more efficient for females.
Total prey weight provisioned is probably a good indirect measure of parental time investment in A.sabulosa. Other measures, particularly number of prey provisioned, will be less accurate.
Interpopulation differences in pupal size and fecundity are not associated with occurrence of outbreaks in Epirrita autumnata (Lepidoptera, Geometridae)
Authors: RUOHOMÄKI KAI , HAUKIOJA ERKKI 
Published: March 2008

Abstract.

Among‐population differences in pupal mass were studied in a geometrid, Epirrita autumnata. Some Epirrita autumnata populations regularly reach outbreak densities while others are never known to do so. Because adults do not feed, pupal mass of females correlates strongly with fecundity.
Larvae were collected from twelve field sites. Ten of our sample populations originated within the outbreak range of the species and represented different phases of outbreaks. Two populations originated outside the outbreak range.
Pupal mass of field‐collected E. autumnata varied significantly among populations. The peak phase populations had the smallest pupae and the biggest were found in low density populations outside the outbreak range.
Offspring of moths from each population were reared under identical conditions in two larval densities. Significant differences were not found in pupal mass among populations. That is, the inherent size, correlated with fecundity of moths, was not different between populations originating within and outside the outbreak range, nor among collections from different densities or phases of the outbreaks.
Rearing density did not interact in a consistent way with population.
As far as size and fecundity are concerned, the results do not support Chitty's hypothesis that differences in genetic composition of the population at low and high density phases generate cyclic fluctuations of population density.
Because no hereditary or maternal differences were found in size and fecundity between E.autumnata originating within and outside the outbreak range, variation in reproductive capacity cannot explain why outbreaks occur only in some populations.
Adaptive superparasitism in solitary parasitoids: marking of parasitized hosts in relation to the pay‐off from superparasitism
Authors: VISSER MARCEL E. , LUYCKX BART , NELL HENK W. , BOSKAMP GÉ J.F. 
Published: March 2008

Abstract.

The pay‐off from an egg laid in a parasitized host is an important parameter in models on adaptive superparasitism in solitary insect parasitoids.
For Leptopilina heterotoma, a parasitoid of larval Drosophila, the pay‐off from a second egg laid in a host is 0.43 offspring when the interval between the two ovipositions is less than 3h. For longer intervals, this pay‐off decreases to almost zero for an interval of 24 h.
When a female encountering a parasitized host is able to estimate the interval since the first oviposition, it is expected that she will take this into account in her host selection decisions. This is, however, not in the direct interest of the female that lays the first egg, and marks the host.
We studied whether superparasitism in hosts containing a young egg is more common than in hosts containing an older egg, when searching in a patch containing once‐parasitized and unparasitized hosts.
The acceptance/encounter ratio of parasitized hosts increased for intervals longer than 6h, as predicted when the interests of the marking female and the longevity of the mark are taken into account.
Superparasitism occurred more often when parasitoids had previously searched a host patch 7 days before the experiment compared to when parasitoids had searched a patch 1 day before, a phenomenon predicted by dynamic optimal diet models.
Oviposition choice and larval survival of Dasineura marginemtorquens (Diptera: Cecidomyiidae) on resistant and susceptible Salix viminalis
Authors: LARSSON STIG , STRONG DONALD R. 
Published: March 2008

Abstract.

Substantial intraspecific variation exists in Salix viminalis resistance to the gall midge Dasineura marginemtorquens. Earlier work has found this variation to have a large genetic component. Willow clones are stable in their resistances between midge generations and different nutrient levels in both field and laboratory culture.
This study reports the results of laboratory experiments on female oviposition choice and larval survival on potted plants from clones that are very different in resistance as determined in field studies.
In choice experiments using pairs of plants, the average female midge did not prefer susceptible willow clones over resistant ones for oviposition. In about one third of the replicates, midges actually laid more eggs on the resistant clone. Further work is necessary to examine the nature of variation among midges in discrimination of these plant types.
Resistance is manifested as great differences in larval survival. Six days after oviposition survival was 92% on susceptible plants but only 6% on resistant ones. Galls developed on all of the susceptible plants, while in 73% of the resistant plants galls were not even initiated.
The plant traits causing resistance are enigmatic. Larval behaviour suggests that resistant plants interfere with feeding behaviour. On resistant plants, most larvae wander for more than 24 h without initiating any galls before dying. On susceptible plants many first instar larvae begin feeding and initiate galls within this period.
Cost of shield defence for tortoise beetles (Coleoptera: Chrysomelidae)
Authors: OLMSTEAD KAREN L. , DENNO ROBERT F. 
Published: March 2008

Abstract.Tortoise beetle larvae possess a shield composed of exuviae and faeces which functions as an effective defence against some invertebrate predators.In the laboratory,Charidotella bicolor, Deloyala guttataandChelymorpha cassidealarvae with their shields experimentally removed did not exhibit enhanced performance (i.e. decreased development time, increased body mass, or higher survival) compared to control larvae with shields intact.Disturbance caused during shield removal did not adversely affect larvae because performance did not differ among controls (undisturbed larvae with intact shields), disturbance controls (shield removal simulated, but shield left in place), and larvae with shields removed.Larvae without shields did not exhibit compensatory feeding to reconstruct the shield following its removal.In a field experiment in which predators were excluded, larvae with shields removed did not develop faster than controls; in fact, survival was slightly reduced (10%) for larvae without shields and may have resulted from desiccation.For slow‐moving tortoise beetle larvae, the cost of bearing the shield is minimal. Thus, larval shields, composed of recycled waste products, provide an inexpensive mode of protection from some natural enemies.
The extinction and foundation of local butterfly populations in relation to population variability and other factors
Authors: POLLARD E. , YATES T. J. 
Published: March 2008

Abstract.

Definitions were adopted for the identification of the extinction and foundation of populations in data from the Butterfly Monitoring Scheme from 1976 to 1991. The data are indexes of abundance, not population estimates.
The frequency of extinctions and foundations for twenty‐eight butterfly species was assessed in relation to characteristics of their population fluctuations, as indicated by fluctuations in the index values.
Using multiple regression, the best predictive equation for the number of extinctions plus foundations included the number of test data available, the mean index per site and the first serial correlation. Two measures of variability were included in the analysis, but were not retained in the best predictive equation.
Some results for individual species are described and the potential of the approach for the study of effects of climatic warming is emphasized.
Behaviour of specialist and generalist caterpillars on plantain (Plantago lanceolata)
Authors: STAMP NANCY E. , BOWERS M. DEANE 
Published: March 2008

Abstract.

Foraging patterns of specialist (Junonia coenia Hubner: Nymphalidae) and generalist (Spilosoma congrua Wlk.: Arctiidae) caterpillars on five genotypes of plantain (Plantago lanceolata L.: Plantaginaceae) were examined in an experimental garden.
Movement by the specialists reflected declining availability of new leaves. When direct sunlight was available, these caterpillars were usually exposed to it.
Although the generalists also preferred new leaves, they spent less than 50% of their time on the plantain and changed location more frequently than the specialists. They often hid at the base of plants or under leaves.
Plant genotype influenced the apparency of the specialists and damage by the herbivores.
Monogamy to communal breeding: exploitation of a broad resource base by burying beetles (Nicrophorus)
Authors: TRUMBO STEPHEN T. 
Published: March 2008

Abstract.

To investigate the range of resource size that burying beetles (Nicrophorus) exploit, small (21–33 g), medium (50–90 g) and large (120–210g) carcasses, were placed in the field and then exhumed after 1, 4, 8, 12 or 18 days.
Nicrophorus attempts to utilize carcasses over this entire size range but has greater success on smaller carcasses.
Larger carcasses were more difficult to exploit because: (a) they took longer to conceal beneath the leaf litter; (b) they were less likely to be rounded into brood balls; (c) they were more likely to be utilized by dipterans; and (d) they were occupied by greater numbers of congeners.
Larger carcasses, however, did support greater numbers of larvae and contained broods of greater total mass than smaller carcasses.
Beetles sometimes bred communally on larger carcasses in the field and same‐sex adults were observed to feed young.
Two follow‐up experiments were conducted in the laboratory. On a large carcass N.defodiens, N.tomentosus or N.orbicollis can raise a maximum of 35–50 young. Nicrophorus pustulatus, in contrast, appears to be unique among Nicrophorus in that it can raise nearly 200 young on larger carcasses.
Nicrophorus orbicollis and Nicrophorus sayi are extremely dependent on parental regurgitations and young fail to survive to the second instar if parents are removed. Young of Nicrophorus defodiens, N.tomentosus and N.pustulatus can develop normally without parental regurgitations.
I discuss these results in the context of reproduction on carcasses of different size and hypothesize that this breeding system is facultatively quasisocial.
Abundance and stratification of foliage arthropods in a lowland rain forest of Cameroon
Authors: BASSET YVES , ABERLENC HENRI‐PIERRE , DELVARE GERARD 
Published: March 2008

Abstract.Arthropod densities and apparent leaf damage were compared within the canopy ecotone and the shrub layer of a lowland rain forest in Cameroon, using a branch clipping method.Most of the individuals collected consisted of ants (average 44%) and various herbivores (31%). Overall arthropod densities amounted to 17 individuals per sample, which, on average, consisted of 0.85 m2of foliage area. Arthropod densities were lower than on temperate foliage.Arthropod densities were about 3 times higher in the canopy than within the shrub layer. In particular, ants and herbivores were significantly more abundant in the canopy than within the shrub layer. Usually, layer effects rather than site effects appeared to cause greater variance in arthropod abundance.Arthropod species‐richness, as estimated by the number of operational taxonomic units sorted, was higher in canopy samples than in samples obtained from the shrub layer. However, apparent leaf damage was higher within the shrub layer (10.9%) than on the canopy (5.2%).Possible factors responsible for the high densities of ants and herbivores on the canopy and for the high leaf damage within the shrub layer are discussed.
The swarming behaviour of the Scottish biting midge, Culicoides impunctatus (Diptera: Ceratopogonidae)
Authors: BLACKWELL ALISON , MORDUE (LUNTZ) A. JENNIFER , YOUNG MARK R. , MORDUE WILLIAM 
Published: March 2008

Abstract.

Swarms of Culicoides impunctatus males were examined in the field in Scotland. Most swarms were close to midge emergence/breeding grounds over a variety of vegetation, some of which clearly acted as swarm markers. Low light (0–1000 lux) and still/humid conditions favoured swarming.
Swarm size ranged between less than 10 and more than one thousand midges. The modal size was 200 individuals. The smallest swarms were usually columnar in shape and the larger swarms ovoid.
Midges behaved individually within swarms, moving in an elliptical manner characteristic of other dipterans in swarms.
Swarms were classified as either ‘persistent’ or ‘transient’ in terms of their shape, size and stability. Wind was the most influential factor in disrupting swarms.
Swarms were confirmed as mating sites for C.impunctatus.
Foraging by honeybees on Carduus acanthoides: pattern and efficiency
Authors: GIURFA MARTIN , NÚÑEZ JOSUÉ A. 
Published: March 2008

Abstract.

The relationship between the fluctuation in total quantity of sugar available in the nectar of Carduus acanthoides inflorescences and the foraging behaviour of honeybees Apis mellifera ligustica was studied in a patch under natural conditions.
Every day, three inflorescence populations coexisted, one for each day of the inflorescence life‐span. The maximum availability of sugar occurred in second‐day capitula from 12.00 to 15.00 hours.
Bee arrivals at the patch were positively correlated with the total availability of sugar as determined by sampling.
Bees responded to variation in the availability of sugar by visiting the inflorescence stage that was most rewarding at that time of day. Early in the morning, when the frequency of visits was low, the bees worked the third‐day capitula, which were the best available choice at that time. Similarly, beginning at 12.00 hours, bees switched to second‐day capitula. At the end of the day, some bees switched to third‐day capitula where a slightly superior quantity of sugar could be obtained from a small number of florets although other bees continued to work the second‐day capitula.
Individual bees switched to another inflorescence stage after a high proportion of their visits to a small number of capitula of one kind had provided a low reward.
The number of florets visited per minute per bee varied throughout the day and was positively correlated with the availability of sugar.
Population studies of Cheilosia fasciata (Diptera: Syrphidae), a leaf miner of Allium ursinum
Authors: HÖVEMEYER K. 
Published: March 2008

Abstract.

Population dynamics of Cheilosia fasciata were described based on a sampling programme covering all developmental stages.
Failure to oviposit and mortality which was due to parasitization of pupae contributed most to total generation mortality.
Abundance of older larvae was regulated by density‐dependent intraspecific competition for food.
These findings were reinforced by a field experiment which manipulated food levels and suggested that losses in numbers on ‘low food’ plots were in part compensated for by producing low‐sized adults.
Adjacent trophic‐level effects on spatial density dependence in a herbivore—predator—parasitoid system
Authors: CAPPUCCINO NAOMI 
Published: March 2008

Abstract. 1. Spatial density dependence of enemy/victim relationships (predator/prey and host/parasitoid) were examined for the gall‐making herbivore Eurosta solidaginis (Diptera: Tephritidae), its predator Mordellistena unicolor (Coleoptera: Mordellidae), and a parasitoid of Mordellistena, Schizoprymnus sp. (Hymenoptera: Braconidae), both before and after experimental perturbation of gall density.2. Mordellistena predation did not depend on Eurosta density, nor did Schizoprymnus parasitism of Mordellistena depend on Mordellistena density.3. Schizoprymnus parasitism of Mordellistena depended strongly on the density of Eurosta, the prey of its host.4. The lack of density dependence in enemy/victim relationships may be explained by effects from adjacent trophic‐levels. Ovipositing Schizoprymnus may search for high densities, not of its host Mordellistena, but of its host's prey (Eurosta galls), and ovipositing Mordellistena may avoid patches of high gall density where the risk of being parasitized is greater.
Does gall diameter affect the parasitism rate of Asphondylia borrichiae (Diptera: Cecidomyiidae)?
Authors: ROSSI ANTHONY M. , STILING PETER D. , STRONG DONALD R. , JOHNSON DEREK M. 
Published: March 2008

Abstract. 1. Fertilized field plots of Borrichia frutescens (L.) de Candolle produced plants with a higher apical‐leaf nitrogen content than control plots.2. Gall frequency of the cecidomyiid Asphondylia borrichiae Rossi & Strong on stems of B.frutescens, increased significantly on fertilized plots after approximately 3 months.3. Fertilizer treatment did not result in changes in stem density but did tend to increase proportion of stems flowering and overall plant size. Galls are not normally found on flowering stems.4. Galls grew at a faster rate and to a larger final size on fertilized plots.5. On three sampling dates, per cent parasitism of galls was the same on fertilized and control plots; therefore, this study does not support the galldiameter hypothesis.
Brood raiding and the population dynamics of founding and incipient colonies of the fire ant, Solenopsis invicta
Authors: TSCHINKEL WALTER R. 
Published: March 2008

Abstract. 1. One of the first activities of minim workers in incipient fire ant nests is mutual brood raiding, the amalgamation of nests through the reciprocal stealing of brood and defection of workers.2. Discrete mating flights created cohorts of incipient colonies. About 25% of founding nests survived the claustral period of 16–48 days (depending on season). Early incipient colony mortality was 5–6% per day. Over 60% of this mortality was accounted for through brood raiding. Most colonies raided when each cohort first became active, and many raided more than once. Raid size (number of nests, duration, distance) tended to increase during the summer as colonies grew through raiding. After the raiding period, nest mortality rate dropped 3–10‐fold. Only 1–3% of founding nests were still alive at this time.3. Queens from losing or failed nests tended to abandon their nests and attempted to enter successful ones, often following raiding trails to do so. This emigration was at least as successful as non‐emigration in ultimately achieving the status of reproductrix of a successful nest (about 4%).4. Brood raiding is a dominant process in early population dynamics, probably accounting for most of the early nest mortality. Its effect is to change the venue and unit of competition from nest‐against‐nest to a shifting aggregation of queens, workers and brood involving entire local populations. Nest thinning is thus very rapid, and the boost to the size of winning nests very large, allowing raiding colonies to win the competition for territory, and to achieve the early colony maturity so important to this, and other, weedy species. The importance of winning brood raids may also have driven increased minim production through the evolution of pleometrosis.
The metazoan food webs from six BorneanNepenthesspecies
Authors: CLARKE C. M. , KITCHING R. L. 
Published: March 2008

Abstract.Two contrasting hypotheses concerning patterns in food web structure within pitchers ofNepenthesare tested using new information from six species ofNepenthesfrom Borneo.In general, predictions that webs will be more complex, and the food chains they contain will be longer, the closer they are to the centre ofNepenthesspecies diversity, are supported.ForNepenthes albomarginata, a widespread species with a distinctive north Bornean form, a contrasting pattern is evident explicable in terms of the morphology of the pitchers and local habitat preferences.General explanations for food web patterns will always be susceptible to exception, reflecting nuances of natural history.
The nutritional quality of phloem sap utilized by natural aphid populations
Authors: DOUGLAS A. E. 
Published: March 2008

Abstract.

The amino acid content of phloem exudates from leaves and of aphid honeydew were adopted as indices of the nutritional quality of phloem sap for aphids. Four plant species and associated leaf‐dwelling aphids were investigated: the sycamore Acer pseudoplanatus and sycamore aphid Drepanosiphum platanoides; Prunus domestica (victoria plum) and the mealy plum aphid Hyalopterus pruni; and the spindle tree Euonymus europaeus and broad‐bean Vicia faba, both hosts of the black bean aphid Aphis fabae.
The concentration of amino acids in the phloem exudates varied with: (a) plant species (greater in the herb Vicia than in the tree species), (b) season (greater in the autumn than summer for Acer and Euonymus), and (c) position (greater in flush leaves than mature leaves of Prunus).
For Acer and Prunus and their aphids, the concentration of amino acids in phloem exudates was significantly correlated with the amino acid content of the aphid honeydew.
The amino acids in all exudates and honeydew were dominated by non‐essential amino acids (glutamic acid, glutamine, asparagine or serine, varying with season and between plant species). The sole major discrepancy between the amino acid profiles of exudates and honeydew was the production of asparagine‐rich honeydew by aphids feeding on leaves, whose exudates were dominated by glutamic acid; this applied to both H.pruni on mature Prunus leaves and Drepanosiphum platanoides on summer‐leaves of Acer.
It is suggested that EDTA‐exudation may be a useful technique to study nutritional correlates of aphid life cycles, e.g. the time of migration between primary and secondary plant hosts.