bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size‐related selection of food plants by bumblebees
Authors: BARROW D. A. , PICKARD R. S. 
Published: March 2008

Abstract. 1. A positive correlation between the tongue length of conspecific workers collecting nectar from seven plant species and the corolla length of the flowers probed was found for B.lapidarius and B.pascuomm but not B.terrestris. No simple relationship was found between the volume, sugar weight or concentration of nectar in flowers and the tongue or wing length of probing bees.2. B.terrestris workers collecting pollen from four plant species producing pollen only, were found to differ in size according to the type of pollen presentation mechanism and the pollen content per flower. Body size variation was also related to the foraging of pollen plus nectar from two other plant species.
The harvester ant (Pogonomyrmex badius) midden: refuse or boundary?
Authors: GORDON DEBORAH M. 
Published: March 2008

Abstract. 1. P.badius Latreille, a harvester ant of the southern U.S.A., surrounds its nest mound with small bits of charcoal, previously believed to be incidental refuse, along with other components of the colony's midden.2. Charcoal middens were removed from the nest mounds of colonies in northern Florida. These colonies collected new charcoal and replaced the middens within 7 days.3. Activity rhythms, use of space, and interspecific aggression were compared in experimental and control colonies. When middens were removed, the frequency of invasions of the nest mounds by other species of ants increased. Foreign ants circled the nest mound and interfered with colony activities. Increased numbers of invading ants led to an increase in patrolling and defensive behaviour by the P.badius colonies.4. The charcoal midden is not merely refuse. Instead, it acts as a boundary that deters ants of other species from coming onto the P.badizls nest mound. Ants may use charcoal bits as a repository of a chemical substance functioning as a territorial marker.
Carrot fly cultivar preferences: some influencing factors
Authors: GUERIN PATRICK M. , STADLER ERICH 
Published: March 2008

Abstract. 1. Factors affecting cultivar preferences by the carrot fly Psila rosae F. were examined in choice tests using foliage from carrot lines representing extremes of resistance and susceptibility to attack.2. Flies were offered a choice to oviposit on foliage, artificial substrates impregnated with leaf surface extracts or enclosed in vapours of different cultivars to establish the importance of contact and olfactory stimuli. Susceptible cv. Danvers Half Long 126 foliage was preferred over that of resistant cvs. Clause's Sytan Original and Tip‐Top. But, whereas the Sytan leaf surface extract was as effective as that of Danvers, the surface extract of Tip‐Top was very much inferior as an oviposition stimulant. By contrast, Sytan and Tip‐Top foliar vapours were both more attractive to the fly than that from Danvers.3. Headspace vapours over Sytan foliage evoked significantly higher electroantennogram responses than those from Danvers.4. Cold‐trapped foliar volatiles of Sytan and Danvers were analysed by gas chromatography linked with antennographic detection. Foliage of Sytan released, among other chemo‐stimulants, higher levels of host plant attractants, i.e. green leaf aldehydes and the phenylpropanoids, trans‐asarone and trans‐methylisoeugenol.5. These findings indicate that olfactory and contact chemostimuli may be involved in preferences shown by the carrot fly for carrot cultivars, but these factors alone do not fully account for the preferences observed.
The suitability of damaged willow leaves as food for the leaf beetle, Phgiodera versicolora
Authors: RAUPP MICHAEL J. , DENNO ROBERT F. 
Published: March 2008

Abstract. 1. The effect of previous damage on the suitability of willow (Mix bubylonicu and S.ulbu‘Tristis’) leaves as food for the imported willow leaf beetle, Plugiodera versicoloru Laich. (Coleoptera: Chrysomelidae), was evaluated by feeding adults and larvae leaves from damaged and undamaged branchlets.2. Females had lower fecundity when fed leaves from artificially damaged branchlets of S.ufba‘Tristis’. A similar result was obtained when beetles ate leaves from naturally damaged branchlets of S.babylonica.3. Feeding preference tests suggest that the reductions in leaf suitability were not due to adults avoiding damaged leaves as a food source.4. PZugiodera versicolora larvae required longer to develop and attained a lower adult weight when fed leaves from damaged branchlets.5. Changes in leaf suitability brought about by herbivore feeding may affect the seasonal abundance of P.versicoloru on its willow hosts.
The life cycles and growth of Carabus glabratus and C. violaceus in Budalen, central Norway
Authors: REFSETH DAGFINN 
Published: March 2008

Abstract. 1. The seasonal activity patterns of adults and larvae, and the seasonal development of female gonads showed that Curubus glabrafus Payk. and Curubus violaceus L. living in a subalpine habitat are spring (summer) breeders with biennial life cycles.2. As a rule, the adults and third stage larvae hibernate, but C.glubrutus at least can hibernate also at the second larval stage, particularly in years in which unfavourable climatic conditions in the spring delay breeding.3. The adaptive strategies underlying these life history patterns and their possible significance for species diversification and coexistence are discussed.
Can honey bees change foraging patterns?
Authors: WELLS PATRICK H. , WELLS HARRINGTON 
Published: March 2008

Abstract. 1. Foraging patterns were studied using honey bees on artificial flower patches to determine if given individuals could change behaviours under differing conditions.2. Two types of flower patches were used; those simulating a population of flowers, dimorphic for colour, and grids simulating a single colour‐dimorphic inflorescence.3. In the simulated population of flowers bees were individually constant to colour over a range of reward volumes and flower patch sizes.4. Each bee remained individually constant to a flower morph when visiting a population‐type grid but changed to random visitation on the simulated inflorescence.5. On the simulated inflorescence, with morphs providing unequal qualities of reward, most bees foraged on the higher molarity morph.6. Most, but not all bees, failed to minimize uncertainty on the simulated inflorescence.7. On the simulated inflorescence, bees failed to optimize when one morph provided a greater reward volume than did the other.8. In the population of flowers bees flew from flower to flower, whereas, they walked on the simulated inflorescence.
The role of extrafloral nectaries in the herbivore defence of Cassia fasiculata
Authors: BOECKLEN WILLIAM J. 
Published: March 2008

Abstract. 1. An experiment is presented that tests the hypothesis that the extrafloral nectaries of Chssia fasiculata reduce herbivory by attracting pugnacious ants that deter herbivores, and tests the equivalence of two methods of ant exclusion: treatment with Tanglefoot, and nectary excision.2. The protectionist hypothesis is not supported; treatment plants produced as many pods as did control plants.3. Treatment with Tanglefoot is equivalent to nectary excision in terms of pod production4. A graphical model is presented that relates the efficacy of ant protection to plant density and ant activity.
Host‐specific demographic studies of the Mediterranean fruit fly Ceratitis capitata
Authors: CAREY J. R. 
Published: March 2008

Abstract. 1. This study was conducted in Greece using a wild strain of medflies (Ceratitis capitata [Weidemann]) to assess age‐specific vital rates in adults, and development and survival in pre‐adults when reared on different host fruit. The results were used to construct life tables.2. The demographic analyses suggested that there are basically four aspects of the medfly's life history which are of major importance: (i) multiple, highlyoverlapping generations; (ii) high net reproduction while young; (iii) high larval fitness in certain hosts; (iv) lack of diapause.3. Reasons why these characteristics are felt to be important are briefly discussed.
Organization of a parasitoid community associated with a complex of galls on Atriplex spp. in southern California
Authors: HAWKINS BRADFORD A. , GOEDEN RICHARD D. 
Published: March 2008

Abstract. 1. Atriplex canescens (Pursh) Nuttall and A.polycarpa (Torrey) Watson (Chenopodiaceae) support twelve morphologically distinct gall types in southern California. Thirty‐seven common species of parasitoids, predators and inquilines are associated with these galls.2. The galls incited by eight members of the Asphondylia atriplicis Cockerell (Diptera: Cecidomyiidae) species complex are linked into a single, interacting community through shared hymenopterous parasitoids and inquilines.3. Cluster analysis (UPGMA) grouped the fifteen most common species of Chalcidoidea into three host guilds of five species each: (1) specialists in tumour stem and blister leaf galls on A.canescens, (2) specialists in woolly stem galls on A.poiycarpa, and (3) generalists that attack all galls. Guild 1 dominated the galls with which it was primarily associated, while guild 3 dominated the remainder.4. The abundances of the parasitoids of the tumour stem and blister leaf galls were negatively correlated with the abundances of two organizer species, a gall‐forming inquiline, Tetrastichus cecidobroter Gordh and Hawkins, and an internal, larval—pupal parasitoid, Tetrastichus sp. B. The abundances of nine of the twelve most common chalcidoids were not correlated with the abundances of all coaccurring species in six other galls.5. Host seasonality partly determines parasitoid population dynamics and guild structure. Parasitoid dominance increased with gall duration, suggesting that parasitoid competition depends on resource stability. The two continuously available galls were dominated by their specialist guild, while all seasonal galls were dominated by generalists. The subdominant specialists of woolly stem galls may represent competitively inferior species that utilize those galls opportunistically, because of the gall's widespread distribution and 9–10 month yearly availability.6. Sites in the Colorado Desert and chaparral that supported several gall types showed stable relative abundances of the major parasitoid species, whereas sites in the Mojave Desert that supported only woolly stem galls had unpredictable parasitoid species assemblages.7. The competitive success of Atriplex gall parasitoids may depend primarily on voltinism (multivoltine species dominated univoltine species) and mode of feeding (phytophagous, mixed entomophagous—phytophagous and facultatively hyperparasitic species in general dominated strict primary parasitoids).
Host relations, life cycles and multiparasitism in some parasitoids of aphidophagous Syrphidae (Diptera)
Authors: ROTHERAY GRAHAM E. 
Published: March 2008

Abstract. 1. Records of parasitism from the field and host choice experiments suggest that most parasitoids of syrphids are monophagous. A few are oligophagous.2. To elicit egg release, females require a stimulus from the host haemolymph. Differential response to haemolymph cues by females may account for the observed pattern of host relations.3. Differences in host ranges and timing of female flight periods probably characterize most of the parasitoids studied.4. In one case of two monophagous parasitoids, Diplazon pectoratorius (Thunberg) and Syrphophilus tricinctorius (Thunberg) attacking the same host Syrphus ribesii (L.) no partitioning was found. Stricinctorius is, however, a superior intrinsic competitor.
Why does the hoverfly Metasyrphus corollae migrate?
Authors: SVENSSON BO G. , JANZON LARS‐ÅKE 
Published: March 2008

Abstract. 1. Migration pattern and mass appearance of the hoverfly Metasyrphus corollae (F.) (Diptera, Syrphidae) were investigated on the SE coast of Sweden in 1981. In total, 4433 hoverflies, belonging to fifteen species, were collected in water traps during 4–6 August. All but 2.2% were M.corollae, 3282 specimens being caught on 4 August, 1021 on 5 August and thirty‐five on 6 August.2. The sex ratios (♂/♀) on these dates were 1/1.6, 1/1.3 and 1/1.7. The average dry weights did not significantly differ between sexes (males 4.01 mg, females 4.02 mg).3. M.corollae females were reproductively immature.4. Females mostly had Senecio pollen in their guts while males mainly had Rubus pollen. The average number of pollen grains per specimen was 210 for females and 1100 for males.5. In the summer 1980 aphids were numerous, forming a basis for a high abundance of adult hoverflies (with hibernating larvae) in 1981. Aphid density in 1981 was low and stimuli inducing egglaying were sparse. It is suggested that this pattern of aphid abundance triggers migration in M.corollae and in other aphidophagous species at irregular intervals.
Fitness of two sibling species of Asobara (Braconidae:Alysiinae), larval parasitoids of Drosophilidae in different microhabitats
Authors: VET LOUISE E. M. , JANSE CHRIS J. 
Published: March 2008

Abstract. 1. Two sibling species of larval endoparasitoids of Drosophilidae: Asobara tabida (Nees) and A.rufescens (Foerster) occur in the same macrohabitat, but inhabit different microhabitats. Each species is most attracted by odours of its own microhabitat.2. In order to assess the adaptive value of the microhabitat preference we studied the survival of both parasitoids in the major host species that occur in these microhabitats.3. Survival in the major host in the preferred microhabitat was shown to be 40% higher for A.tabida and 30% higher for A.rufescens when compared to survival in the major host in the non‐preferred microhabitat.4. Measurements of developmental rates, specific mortalities and dry weights of the parasitoids suggest that the differential survival is due to differences in synchronization with the hosts.5. The possible evolutionary consequences of some biological characteristics in Asobara are discussed. Microhabitat selection, differential survival, development and mating behaviour are attributes likely to have played a role in the reduction of gene flow between populations of the ancestral species, either in primary or in secondary sympatry.
Contrasting movement patterns of nectar‐collecting and pollen‐collecting bumble bees (Bombus terricola) on fireweed (Chamaenerion angustifolium) inflorescences
Authors: GALEN C. , PLOWRIGHT R. C. 
Published: March 2008

Abstract. 1. Movements of nectar and pollen‐foraging bumble bees on inflorescences of Chamaenerion angustifolium (L.) J. Holub (fireweed or rosebay willow herb) were compared with predictions based on reward distributions and optimality principles. Observations suggest that nectar and pollen‐gathering bumble bees behave according to the same set of reward maximization criteria when foraging from flowers of this species.2. Both kinds of foragers matched their arrival points with the vertical positions on inflorescences in which the densities of their respective food resources were greatest. For nectar‐foragers, this point was located at the lowest tier of flowers, whereas for pollen‐foragers it was found in the middle of the inflorescences. Nectar and pollen‐foraging bees both moved upward on inflorescences following gradients from high to low reward availability.3. Nectar‐foragers responded to decreases in inflorescence size over the season by reducing the number of flower visits made on each raceme. Number of flowers visited by pollen‐foragers was low throughout and reflected the scarcity of male‐phase flowers on racemes. Flower revisitation rates were low for both kinds of workers, but were slightly higher for those collecting pollen.
Bracken, ants and extrafloral nectaries. III. How insect herbivores avoid ant predation
Authors: HEADS P. A. , LAWTON J. H. 
Published: March 2008

Abstract. 1. Ants (Myrmica spp. and Formica lemani) visiting the extrafloral nectaries of bracken, Pteridium aquilinum, imposed heavy mortality on caterpillars of a novel moth species experimentally introduced onto bracken fronds. However, the exclusion of ants from bracken fronds had no significant effect on adapted bracken‐feeding herbivores in Britain.2. The feeding stages of British bracken‐feeding insects are immune to, or can largely avoid, predation by ants in a variety of ways. Gall formers and miners cannot be attacked by these ants. Two other species hide, one inside tied leaves, the other in a mass of ‘spittle’. Another group of species jumps away from, or falls off the plant when touched by ants. Sawfly caterpillars in the genera Strongylogaster, Aneugmenus and Tenthredo have viscous, distasteful haemolymph that repels ants.3. No species of bracken herbivore has an absolute temporal refuge from ants; during their development they all overlap with ants to some degree.4. Ant predation appears to have played a significant role in determining the contemporary structure of British bracken‐feeding insect communities. Distasteful haemolymph in sawfly caterpillars may have evolved in response to selection from ant predation. Other species may fortuitously possess characteristics, evolved in response to a variety of selective forces, that also reduce the impact of ants; without such characteristics, however, we postulate that they would be unable to live on this plant. An absence of external, foliage feeding Lepidoptera early in the spring, a high proportion of sawfly species, and a high proportion of gall‐formers and miners may all be characteristics of the bracken herbivore community which have been influenced by ant predation.
Ecological strategies of Dalbulus leafhoppers
Authors: NAULT L. R. , MADDEN L. V. 
Published: March 2008

Abstract. 1. Developmental times from egg to adult eclosion were established for eight Dalbulus leafhopper species on maize (Zea mays) and its perennial, gamagrass relative, Tripsacum dactyloides. Experiments were conducted with a 16 h day (25–27°C) and an 8 h night (21–22°C).2. Developmental times were shortest for the maize specialists, c. 26 days for D. maidis and c. 27 days for D. elimatus, and longest for the Tripsacum specialists, c. 32 days for D. tripsacoides, c. 34 days for D. quinquenotatus and c. 40 days for D. guzmani. Developmental times were intermediate for D. gelbus, D. longulus and D. guevarai, species that utilize both maize and Tripsacum as field hosts.3. For all species, development was significantly faster on maize (species mean 29 days) than on T. dactyloides (species mean 34 days).4. D. maidis and D. elimatus developed significantly faster (c. 3 days) on maize than on its close perennial relative, Z. diploperennis.5. As measured by a 48 h oviposition period, D. maidis, D. elimatus and D. gelbus produced significantly more progeny on maize than on gamagrass. D. quinquenotatus produced more progeny on T. dactyloides than on maize. D. maidis and D. elimatus produced more progeny on maize than on Z. diploperennis.6. These studies provide support for the hypothesis which predicts that herbivorous insects that specialize on annual plants will have a shorter generation time and be more fecund than perennial specialists. The genus Dalbulus appears to be composed of species that fit an r‐K continuum, with maize specialists and Tripsacum specialists at opposite ends of the continuum.
The function of multiple anti‐predator mechanisms in adult tiger beetles (Coleoptera: Cicindelidae)
Authors: PEARSON DAVID L. 
Published: March 2008

Abstract. 1. Predator avoidance mechanisms of adult tiger beetles (Cicindela spp.) were investigated in the Sulphur Springs Valley of southeastern Arizona, U.S.A.2. The predators were found to be robber flies, lizards, and birds.3. Effective antipredator characters included body size, orange abdomens, defence chemicals, flight and gregariousness.4. The number of these five major antipredator mechanisms exhibited by each tiger beetle species varied with habitat.5. The function and number of antipredator mechanisms was a complex interaction of deterrents; some were effective only in combination and some were characters that each deterred a different type of predator; in several cases, the characters that reduced the probability of attack by one type of predator simultaneously increased the probability of attack by another type of predator.
Effects of leaf toughness on mandibular wear of the leaf beetle, Plagiodera versicolora
Authors: RAUPP MICHAEL J. 
Published: March 2008

Abstract. 1. The effects of leaf toughness on mandibular wear of the leaf beetle Plagiodera versicolora Laich. (Coleoptera: Chrysomelidae) were evaluated by feeding adult beetles young (tender) and old (tough) leaves of Salix babylonica and S. alba ‘Tristis’.2. Tough leaves erode the cutting surface of beetle jaws more so than tender leaves.3. Beetles with worn jaws consumed leaves at a slower rate than ones with less mandibular wear.4. Because rates of leaf consumption and egg production are positively correlated, increased mandibular wear may reduce beetle fecundity.5. These results support the belief that leaf toughness may act as a potent defence affecting morphology, feeding behaviour, and ultimately spatial and temporal patterns of herbivores.
Seasonal changes in the response of wood‐ants (Formica lugubris) to sucrose baits
Authors: SUDD J. H. , SUDD M. E. 
Published: March 2008

Abstract. 1. The acceptability of sucrose solutions to Formica lugubris Zett. in the field was tested by offering droplets of known concentrations to ants tending aphids.2. A probit model fitted to the data allowed the computation of the Median Effective Concentration (ED50) and its confidence limits.3. In spring and early summer ED50 was about 0.15 M sucrose, but the ED50 rose in 1 week at the end of June from 0.2 M to 0.9 M. The change was simultaneous on pine and birch trees. The ED50 fell gradually to about 0.4 M in early November.4. The increase in ED50 is related to the production of the summer apterae in the aphids tended, Cinara pini (L.) on pines and Symydobius oblongus (von Heyden) on birch. This increases the ‘quality’ of food resource so that low sucrose concentrations can no longer compete for ant attendance.5. The increase in ED50 may limit the attendance of wood‐ants at the nectaries of bracken, Pteridium aquilinum (L.) Kuhn. and at colonies of some other aphid species which are attended only in early summer.
Phenological relationships of wasps, bumblebees, their mimics and insectivorous birs in northern Michigan
Authors: WALDBAUER G. P. , LaBERGE W. E. 
Published: March 2008

Abstract. 1. In northern Michigan 72% of the high fidelity dipterous Batesian mimics of bumblebees and vespoid wasps occurred in spring while they still outnumbered their models but before the great majority of fledgling birds left their nests to begin foraging for insects on their own.2. This extends the known occurrence of this sort of phenology to several additional mimetic species and to an area which is radically different climatically and ecologically from the central Illinois areas in which this sort of phenology was first noted.3. Our observations confirm the hypothesis that Batesian mimics may be selected to avoid the midsummer period when newly fledged insectivorous birds are abundant but have not yet learned to shun their stinging hymenopteran models.4. The shortness of the warm season in Michigan reduces opportunities for temporal separation and may have forced the other 28% of the high fidelity mimics to occur when naive birds are abundant. The threat from naive birds was, however, presumably somewhat ameliorated by the abundance of models at that time.