bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hygrothermal determinants of insect activity patterns: the Diptera of water‐lily leaves
Authors: WILLMER P. G. 
Published: March 2008

Abstract. 1. The numbers and types of flies resting on water‐lily leaves varied through the diurnal cycle. The different patterns of occupancy were recorded in relation to time of day and to microclimatic conditions at the leaf surface.2. Overall fly activity on the leaves varied according to gross climatic patterns on particular days. The timing of activity differed according to species.3. Smaller, darker flies (especially ernpids and Notiphila) were common on the leaves early and late in the day, with the more reflective dolichopodids occurring only towards midday and in full sun. Hence there were clearcut correlations between both the size and reflectance properties of flies, and the climate (in particular radiation received at the leaf surface); though this pattern was superimposed on a diurnal activity effect.4. The timing of insect activity on the leaves could therefore be related to hygrothermal considerations, particularly the raising and maintenance of body temperature and avoidance of heat stress. Different types of fly used the favourable microclimate around the leaves as a resting site at times appropriate to their own biological requirements.
Adaptative significance of a temperature induced diapause in a cosmopolitan parasitoid of Drosophila
Authors: CARTON Y. , CLARET J. 
Published: March 2008

Abstract. 1. We have previously demonstrated pre‐pupal diapause in a tropical population of Leptopilima boulardi Barbotin, Carton and Kelner‐Pillault (Cynipidae, Hymenoptera), a larval parasitoid of Drosophila melanogaster Meigen. Prepupal diapause was induced by low temperature (17.5°C) but absent at 25°C; it was independent of photoperiod.2. Four populations which originated from different latitudes (4°S to 44°N) exhibit the same response to temperature without any major genetic geographical variation.3. In temperate areas, this diapause may permit a phenological and temporal coincidence between the parasitoid and its host whose larval growth is only possible for temperatures above 13°C.4. The significance of the persistence of this diapause in tropical areas is discussed.
Cold‐hardiness and development of eggs of Rhopalosiphum insertum
Authors: JAMES B. D. , LUFF M. L. 
Published: March 2008

Abstract. 1. The eggs of Rhopalosiphum insertum (Walker) showed a seasonal increase in cold‐hardiness under field conditions. Their supercooling point fell from ‐35°C in November to below ‐40°C in January, then rose to‐35°C or above by March.2. Laboratory experiments demonstrated that both temperature and date affected cold‐hardiness of the eggs. The supercooling points of eggs kept at 16 h photoperiod or in darkness did not, however, differ significantly.3. Eggs brought from the field into warm, long‐day conditions would not hatch until after mid‐January. After this date, per cent hatch was significantly greater in 16 h photoperiod than in darkness; it did not differ between eggs kept at 5 or 0°C, but was reduced at ‐5°C.4. It is concluded that eggs of Rinserturn are in diapause until mid‐January, and that hatching rate and cold‐hardiness are determined by separate environmental factors.
The basis of an apparent preference for isolated host plants by ovipositing Euptychia libye butterflies
Authors: MACKAY DUNCAN A. , SINGER MICHAEL C. 
Published: March 2008

Abstract. 1. The tendency of Euptychia libye butterflies to oviposit with greater likelihood on isolated plants than on members of clumps is evident in the field and can be duplicated under controlled conditions in the laboratory.2. The causes and effects of this behaviour and the difficulties inherent in inferring preference from egg distributions in the field are discussed.
Satiation and the functional response: a test of a new model
Authors: MILLS N. J. 
Published: March 2008

Abstract.1. A model of the functional response to prey density is derived to include the reduction in time available for search,Ts, resulting from predator satiation.2. For larger prey items predator satiation occurs at each prey capture andTsis reduced by the attack time and digestive pause of a series of attack cycles. For small prey items predator foraging is continuous at low densities withTsreduced solely by attack time. At higher densities predator satiation occurs after the capture of several small prey items andTsis reduced by the attack time and digestive pause of a series of foraging cycles.3. A comparison of the predicted asymptotic level of prey capture using experimentally estimated parameter values, with the maximum consumption of aphids by larval and adult coccinellids provides a test of the satiation model.4. The limitation of prey capture by predator satiation is discussed with reference to handling time and the success of coccinellids in biological control.
Strategies in energy consumption and partitioning in Collembola
Authors: TESTERINK G. J. 
Published: March 2008

Abstract. 1. Consumption (in Joules), partitioning of assimilated energy between maintenance (standard metabolism and locomotory activity) and prcduction (growth and reproduction) and assimilation efficiency were studied in the laboratory using adults of the coexisting species Orchesella cincta (L.) and Tomocents minor Lubbock (Collembola, Entomobryidae).2. A higher energy demand for maintenance was established in O.cincta, compared with T.minor, caused by a higher mobility and a higher live weight‐specific oxygen consumption (metabolic rate).3. The energy required for higher maintenance in O.cincta, compared with T.minor, was derived from production, both from growth and reproduction.4. The increase in live weight (in mg) during a moulting interval (feeding instar plus reproductive instar) was less in O.cincta than in T.minor, and was less in males than in females.5. Reproduction (in Joules) was less in O.cincta than in T.ninor. The numbers of eggs produced were equal, but their energetic content was less in O.cincta. Survival of the eggs was similar.6. Consumption (in Joules) and assimilation efficiency (on an energetic basis) during a moulting interval (feeding instar plus reproductive instar) were similar in both species.
Morph determination in Melittobia, a eulophid wasp
Authors: FREEMAN B. E. , ITTYEIPE K. 
Published: March 2008

Abstract. 1. The Caribbean and Central American eulophid wasp, Melittobia sp. 1 (hawaiiensis complex), (Hymenoptera: Chalcidoidea), whose larvae are exophagous on the prepupae of solitary wasps and bees, has three adult female and two adult male morphs.2. The males, which constituted only 5% of the progeny, had morphs with, and without, ocelli.3. In the females, brachypterous, negatively phototactic ‘crawlers’ developed mainly at low densities (<8.9 eggs cm‐2), while above this density an increasing number and percentage of macropterous, positively phototactic ‘fliers’ were produced. Intermediate ‘jumpers’ were positively phototactic but could not fly.4. In a typical progeny twenty to thirty ‘crawlers’, twenty to forty ‘jumpers' and up to 400 ‘fliers’ emerged in an overlapping sequence.5. Experiments demonstrated that the proportions of the three morphs emerging were unrelated to the sequence in which the eggs were laid, to the species of the host and to the quality and absolute amount of food given, but related only to the density experienced by the young larvae.6. We relate this trimorphism of dispersive female morphs to the three levels of ecological space (food item, patch and distribution of patches) postulated by Hassell & Southwood (1978) and suggest the general ecological conditions necessary for it to evolve.
The impact of forest cutting on the diversity of ground beetles (Coleoptera: Carabidae) in the southern Appalachians
Authors: LENSKI RICHARD E. 
Published: March 2008

Abstract.1. Carabid beetles were sampled by means of pitfall traps on several clearcut areas and in adjacent forests.2. A hierarchical analysis of diversity revealed a significant increase in the within‐genus component of species diversity after forest cutting.3. This trend in intrageneric diversity was obscured, with respect to total species diversity, by a nonsignificant reduction in diversity at the generic level.4. The increase in the within‐genus component of species diversity following forest cutting was consistent with the hypothesis that disturbance of a cornmunity can disrupt processes of competitive exclusion.
Leaf wilting alters a plant species ranking by the grasshopper Melanoplus differentialis
Authors: LEWIS A. C. 
Published: March 2008

Abstract. 1. Field observations of the feeding behaviour of the polyphagous grasshopper Melanoplus differentialis suggest that plant quality can override plant species as a determinant of choice. When offered binary choices in laboratory tests between leaves of two host plant species, Helianthus annuus and Ambrosia trifida, in all combinations of wilted and turgid, grasshoppers prefer A. trifida in all test conditions, except when it is turgid and H.annuus is wilted. In this case, the preference switches to H.annuus2. Preliminary evidence suggests that chemical factors are responsible for the alteration in preference.
Fitting split‐lines to ecological data
Authors: PERRY J. N. 
Published: March 2008

Abstract.1. Ecological data from a variety of sources are often well fitted by a ‘split‐line’ relationship. The position of the peak and rates of growth to, and decline from this peak may be estimated. Examples are given for aphid data.2. Invalid fits are explained and procedures given to choose the best valid fit. Examples are given for phorid data.3.Techniques are described for fitting, simultaneously, different split‐lines to several sets of data, comparing parameters and finding the simplest adequate description of the data. Examples are given for earthworm data.
Influence of intertree distance on foraging behaviour of Rhagoletis pomonella in the field
Authors: ROITBERG BERNARD D. , PROKOPY RONALD J. 
Published: March 2008

Abstract. 1. We tested a prediction from contemporary foraging theory that animals should decrease their allocation of energy to the searching of individual patches when interpatch travel costs decrease.2. We used individual Rhagoletis pomonella Walsh (Diptera: Tephritidae) females foraging for oviposition sites (=Crataegus fruit) in a host tree which was surrounded by four other trees at varying distances.3. We found that flies generally invested less search, measured as time spent searching a tree or number of leaves visited on a tree, when neighbouring trees were nearby than when farther away.4. Under our test conditions, flies appeared to have difficulty locating neighbouring trees at a distance of more than 1.6 m.5. Our study calls into question the interpretation of search effort by insects within resource patches in the absence of information on interpatch distances.
Prey attraction by luminous larvae of the fungus gnat Orfelia fultoni
Authors: SIVINSKI JOHN 
Published: March 2008

Abstract. 1. Bioluminescence in predacious larvae of the fungus gnat Orfelia filtoni attracts potential prey.2. Transparent traps placed over larvae caught more arthropods than opaque traps put over neighbouring conspecifics.3. Small Diptera are particularly vulnerable to light lures, while apterous soil arthropods are seemingly unaffected.
Mimicry in North American checkerspot butterflies: Euphydryas phaeton and Chlosyne harrisii (Nymphalidae)
Authors: BOWERS M. DEANE 
Published: March 2008

ABSTRACT.

An examination of the phenetics, ecology and distribution of Chlosyne harrisii suggested that it was a potential mimic of the unpalatable Euphydryas phaeton.
The wing undersurfaces of the adults are very similar and the larvae are virtually identical. The geographic range of both butterflies is the northeastern United States and both are inhabitants of wet meadow habitats where they may fly together. The life histories of both species are closely synchronized.
A series of feeding experiments using blue‐jays as predators showed first, that C.harrisii is palatable, and second, suggested that the birds could not distinguish between C.harrisii and E.phaeton on the basis of visual cues. Thus, Charrisii seems to be an effective Batesian mimic of E.phaeton.
Frequency‐dependent selection in the grazing behaviour of the desert locust Schistocerca gregaria
Authors: CHANDRA S. , WILLIAMS G. 
Published: March 2008

ABSTRACT.

The locust displayed clear preferences in the ranking of five possible food plants: wheat > barley =Cypeius alternifolia > chives > lemon grass.
In two‐species stands of constant numerical density, the locust grazed selectively on the less‐favoured plant when it was relatively less abundant.
The behavioural mechanism of selective grazing was a change in the readiness to eat a plant as its relative frequency changed: i.e. the consumption/encounter ratio rose as relative density fell.
With the exception of Cyperus, which nutritionally is below chives, the preference ranking matched nutritional ranking as estimated by rearing‐success on single plant species.
It is suggested that such negative frequency‐dependent selection may be a common strategy for polyphagous herbivores as it permits a wide dietary intake without hazards from potentially toxic foods.
The hatching stimulus for eggs of Aedes punctor (Diptera: Culicidae)
Authors: FALLIS SIMON P. , SNOW KEITH R. 
Published: March 2008

ABSTRACT.

Eggs of the British woodland mosquito, Aedes punctor (Kirby), were subjected to a variety of media in an attempt to determine the hatching stimulus.
It was found that continuous immersion in distilled water evoked almost no hatching (0.2%); intermittent removal from the water gave low hatching (8.9%).
Slow deoxygenation of the medium by either bacterial growth or the introduction of nitrogen produced the highest level of hatching (26.0–90.0%). Eggs of A.punctor were shown to hatch within a 4 h period of the oxygen concentration in the medium reaching zero.
Emergence of flies from overwintering populations of cabbage root fly pupae
Authors: FINCH S. , COLLIER ROSEMARY H. 
Published: March 2008

ABSTRACT.

Once pupal diapause had been terminated, over‐wintering cabbage root fly (Delia radicum (L.)) pupae from Wellesbourne required a further 14 days at 20°C for most of the flies to emerge.
There were considerable variations in the rates of fly emergence from thirteen populations of cabbage root fly pupae collected between latitudes 50° 42′ and 54° 59′ in England and Wales. These thirteen populations could be grouped into early‐, intermediate‐ and late‐emerging types. In the early‐emerging type, flies emerged within 14 days at 20°C whereas in the late‐emerging type emergence was protracted and was completed only after 100 days at 20°C in one population from Halsall, Lancashire. In the intermediateemerging type, approximately two‐thirds of the flies emerged within 14 days at 20° C, the remainder taking considerably longer.
The intermediate‐emerging types could be just mixtures of the early‐ and late‐emerging types.
Subjecting pupae to diapause‐breaking temperatures (4°C) for up to 1 year failed to shorten the time to subsequent fly emergence in any of the populations.
Populations of early, intermediate‐ and late‐emerging fies could be selected from a parental population, heterogeneous with respect to emergence, within one generation.
The type of emergence that occurred in a locality was not correlated with latitude.
Any models developed for forecasting the most appropriate time to apply insecticide in a locality will have to include information about the emergence pattern of the fly population in that locality.
A field evaluation of the sexual competitiveness of sterile melon flies, Dacus (Zeugodacus) cucurbitae
Authors: IWAHASHI OSAMU , ITO YOSIAKI , SHIYOMI MASAE 
Published: March 2008

ABSTRACT.

The sexual competitiveness of sterile melon fly males [Ducus (Zeugodacus) cucurbitue Coquillett] was estimated under field conditions.
The value of competitiveness was about 0.8 for flies in the fifth to tenth generation from the beginning of mass‐rearing, but decreased to about 0.2 in the eighteenth generation.
The sexual competitiveness estimated using laboratory data was near unity even in the final stage of our study.
It was concluded that the field evaluation of sexual competitiveness is essential to determine the quality of the insects reared for purposes of pest control.
The evolution of parental behaviour in Scarabaeinae (Coleoptera, Scarabaeidae): an experimental approach
Authors: KLEMPERER H. G. 
Published: March 2008

ABSTRACT.Dung beetle lifestyles are reviewed. Most Scarabaeinae lay their eggs in dung masses that are packed into underground chambers, but Coprini and Scarabaeini typically lay their eggs in free‐standing brood balls and it is in these tribes that parental care of the brood has evolved.Brood balls are constructed by aggregating fragments of dung. This technique is derived from the method of gathering dung at the surface. Larvae developing in brood balls are better protected against dehydration and parasite attack. The repair technique of Scarabaeine larvae preadapts them to life in brood balls.Parental care byCopris lunarisdepends on appropriate responses by the female to the brood, and it has the selective advantage of protecting the brood against parasites. Preadaptations for parental care in‘non‐brooding’Coprini are discussed.Variations in the basicCoprisnesting behaviour are summarized. Similar variations can occur spontaneously inC.lunarisand can also be released by unusual circumstances.C.lunarisfemales could in principle cooperate but certain factors have prevented this social evolution. The significance of the transient cooperation with the male beetle is discussed.
Temporal patterns of seed use and availability in a guild of desert ants
Authors: MEHLHOP PATRICIA , SCOTT NORMAN J. 
Published: March 2008

ABSTRACT.

Temporal patterns of seed use were studied from late winter to autumn in three species of seed‐harvesting ants in the Sonoran Desert. Measures of effective foraging activity, dietary niche breadth and dietary niche overlaps were obtained each month and were tested for correlation with estimates of the available seed resource.
Seeds were the only numerically important type of food in the diets of all species.
The ants partitioned the resource according to both seed species and seed size, although there was considerable overlap.
Pheidole xerophila had the smallest forager body size and is a specialist on small seeds because it harvested them in greater proportion than their rank in the soils and expanded its diet to larger seeds only when the abundance of small seeds declined.
When the abundance of the small seeds of Bouteloua barbata decreased, the middle‐sized ant, Veromessor pergandei, showed a decrease in foraging activity, increase in niche breadth, and a decrease in overlap with P.xerophila.
Seed size preferences of V.pergandei did not vary seasonally, except that during the month of highest seed abundance, V.pergandei showed no size preference.
Pogonomyrmex rugosus was the largest ant; it preferred larger seeds and was inactive when small seeds were most abundant. Seasonal foraging activity and niche parameters were random in relation to seed abundance.
We suggest that nocturnal foraging by P.rugosus during the summer months was a response to interference with diurnal foraging by either predation frorn horned lizards or competition from V.pergandei.
Seasonal abundance of small seeds explains most of the seasonal foraging patterns of P.xerophila and V.pergandei. The summertime abundance of larger seeds during years of adequate precipitation may account for the seasonal activity patterns of P.rugosus.
Phenology and life history of Belgica antarctica, an Antarctic midge (Diptera: Chironomidae)
Authors: SUGG PATRICK , EDWARDS JOHN S. , BAUST JOHN 
Published: March 2008

ABSTRACT.

An account of the life‐history with emphasis on phenology and number of instars is presented for Belgica antarctica Jacobs, the southernmost holometabolous insect.
Contrary to earlier reports, Belgica has four instars, in common with most other chironomids. Mean head capsule lengths varied between different populations but no overlap was found between discrete size classes of successive instars.
Belgica overwinters in all four instars.
Relative frequency of different instars from samples taken through the season indicates that a 2‐year life‐span is the commonest pattern.
Emergence of adults is relatively synchronous. Belgica exhibits protandry, which may be established at the time of pupation.
Distribution of the eggs of Aedes punctor (Diptera: Culicidae)
Authors: FALLIS SIMON P. , SNOW KEITH R. 
Published: March 2008

ABSTRACT.

Eggs of the mosquito Aedes punctor Kirby were found to be aggregated in a horizontal band within woodland depressions.
The height of the peak of egg density above the lowest point in the depression varied from 24 to 39 cm in six transect studies.
One depression, 2 m in diameter, was analysed in detail and found to contain a total of 9231 eggs with a maximum density of 944 eggs in a 250 cmz area.
Thermal niche partitioning in the grasshoppers Arphia conspersa and Trimerotropis suffusa from a montane habitat in central Colorado
Authors: GILLIS J. E. , POSSAI KURT W. 
Published: March 2008

ABSTRACT.

Two species of grasshoppers, Arphia conspersa and Trimerotropis suffusa, coexist in a montane habitat in central Colorado.
Field‐recordings of body temperature revealed that A.conspersa has a significantly lower mean body temperature (Tb), sexual display temperature (Td) and minimum flying temperature (MFT) than T.suffusa.
A test of the maximum voluntarily tolerated temperature (MVT) showed that T.suffusa has a higher MVT than A.conspersa.
Thermal niche breadth, as indexed by the difference between MVT and MFT and the range of environmental temperatures over which each species is active, is broader in the eurythermic A.conspersa than in the stenothermic T. suffusa.
Thermoregulatory ability, as evaluated by regression analysis of Tb on Ta, was shown to be better in T.suffusa than in A.conspersa and in displaying grasshoppers of both species than in non‐displaying ones. The significance of these findings with respect to a cost‐benefit model of behavioural thermoregulation in ectotherms is discussed.
Based on these data and observations it was concluded that A.conspersa and T.suffusa occupy different thermal niches and that thermal considerations may be importantly related to habitat preference, daily activity patterns, and consequent ecological separation.
Fugitive species and priority during colonization in carrion‐breeding Diptera communities
Authors: KNEIDEL KENNETH A. 
Published: March 2008

ABSTRACT.

Experiments were conducted to test for the presence of fugitive species and priority effects among the Diptera species that breed in dead slug carcasses (Limax maximus L.).
Slug carcasses exposed for only 1 day produced a community that was very similar to that bred from carcasses exposed until fully decomposed. This suggests that competitive ability and dispersal ability are positively correlated in this system.
The colonization of flies was manipulated by transferring larvae of the phorid, Megaselia scalaris Loew, to carcasses before and after they were exposed in the field. A‘priority effect’was demonstrated in that M.scalaris survived better and had a stronger impact on other species when it was the first species to colonize slug carcasses.