bluuebunny/crossref_metadata_2025_split huggingface dataset:
The biology in Jamaica of the adults of the sphecid wasp Sceliphron assimile Dahlbom
Authors: FREEMAN B. E. , JOHNSTON BEVERLEY 
Published: March 2008

Abstract. 1. The adult biology of the solitary mud‐wasp Sceliphron assimile Dahlbom was studied in Jamaica.2. Adults were active from sunrise until they finally settled in roosting groups a little before sunset. Nesting took place during an 8.5 h period commencing about 3 h after sunrise but individuals rarely spent > 4 h nesting per day, the remainder being spent in resting and feeding.3. Males sought females in all places in the habitat.4. The number of cells per nest was positively correlated to high cell density per unit area but negatively correlated to illuminance.5. The number of pellets used to build a cell, but not cell length, was negatively correlated to the body length of the builder. There is evidence that females that build multiple nests locate them within a few metres of each other.6. Incompletely stored cells were closed with an externally concave lamella of mud at the onset of rain or at 16.00—17.00 hours E.S.T. and never reopened the same day.7. Like other species of Sceliphron studied in this respect S. assimile collected spiders belonging to the Argiopidae (particularly), and also mainly to the Thomisidae, Salticidae and Oxyopidae.8. The consequences of the nest architecture on mortality and the method of building on distribution are discussed.9. Protarrhenotoky and proterandry occur and probably influence the sex ratio through differential mortality and fecundity. A suggested interaction between the flight motor and the ovaries could regulate egg production.
The relationship between density and distance of dispersing insects
Authors: TAYLOR R. A. J. 
Published: March 2008

Abstract. 1. The data for dispersal of Drosophila pseudoobscura of Dobzhansky & Wright (1943) were re‐examined and an improved description found for them.2. The equation that best described the dispersal of D.pseudoobscura was found not to be applicable to the dispersal of five other insect species.3. Eight equations describing the density‐distance relation were fitted to the dispersal data of eight insect species. No equation fitted all the data adequately.4. A general expression was deduced from comparison of the eight equations, and found to fit all species better than any of the special cases.
Insect flotsam: an unstudied marine resource
Authors: CHENG L. , BIRCH M. C. 
Published: March 2008

Abstract. 1. Insect flotsam was obtained from marine pleuston samples from the English Channel (U. K.), off the Oregon coast (U. S. A.), and in the Gulf of California (Mexico).2. Only ten orders of insects were represented, Coleoptera, Diptera and Homoptera being the most abundant.3. Staphylinidae and Chironomidae were the most abundantly represented families taken from the English Channel, comprising 43% and 18% respectively of total insects sampled.4. Aphididae comprised 39% of the Oregon Coast samples.5. Aphididae (42%) and Cicadellidae (17%) accounted for 59% of the insects in the Gulf of California.6. Fish may feed on surface insects at night and this may account for the lower numbers found in early morning samples.
Overwintering ecology of the monarch butterfly, Danaus plexippus L., in California
Authors: TUSKES P. M. , BROWER L. P. 
Published: March 2008

Abstract. 1. Population and physiological measurements were made on monarch butterflies in three overwintering colonies along the California coast during the 1975–76 season.2. Mark, release and recapture studies indicated that two northern colonies (Muir Beach and Santa Cruz) stabilized at maxima of about 40000 and 95 000 individuals with little movement in or out of colonies, whereas the southern one at Santa Barbara appeared dynamic with a maximum of about 45 000.3. Initially low, sexual activity builds to a massive mating ceremony in February, followed by rapid colony dispersal. The butterflies deteriorate gradually during the overwintering period, but males do so to a greater extent because of their involvement in frenzied courting flights.4. Changes in several parameters at the Muir Beach colony were measured between 1 November and 2 February. Right forewing length did not change with time, indicating no differential mortality with respect to size. However, both sexes lost about 25% of their total dry weight, and 49–60% of their lipid contents. Minimum fat levels were about 20 mg and some butterflies were as lean on arrival as were the most depleted overwintering survivors.5. The importance of nectaring in restoring lipid reserves is potentially great but remains uninvestigated. The hypothesis is put forward that the distance spring migrants are capable of flying is dependent largely upon their lipid reserves following the overwintering period. This and the intracolony mass‐mating ceremony are seen as randomizing factors which prevent geographic differentiation and allow the maintenance of the generalized, nature of the migration, which in turn enables the monarch to exploit the vast milkweed flora across the North American continent.6. Cardenolides also diminished during the wintering, but to a substantially lesser extent than the lipids. There was no evidence for a change in the proportion of cardenolide‐positive butterflies, suggesting no differential elimination by predation of the poison‐free palatable individuals. This is the first field evidence in support of the theory of automimicry.7. The overwintering behaviour of the monarch butterfly is seen as an integrative force in optimizing foodplant exploitation, reproduction, anti‐predator, and migration strategies.
The structure of the aquatic insect community associated with intertidal pools on a New Jersey salt marsh
Authors: CAMPBELL BRUCE C. , DENNO ROBERT F. 
Published: March 2008

Abstract. 1. Landlocked intertidal pools (potholes) are one of the common aquatic habitats associated with eastern North American salt marshes.2. Twenty species of insects, of which only eight were common, occurred in the pothole habitat. The harshness of the physical environment incurred in the pothole habitat is largely responsible for this depauperate insect community.3. Spatial variation in the diversity of the insect community is best explained by differential densities of predaceous fish.4. Seasonal changes in insect community diversity are attributable to fluctuations in water temperature and accompanying levels of dissolved oxygen.
Food resource partition in the beech leaf‐feeding guild
Authors: NIELSEN B. OVERGAARD 
Published: March 2008

Abstract. 1. The position and zonation of mines and galls along beech leaves were recorded and analysed by means of an R X C test of independence using the G‐test; in a few cases analysis of variance was applied.2. Ten arthropod species, of which a few were congeneric, were studied. All species were recorded from all leaf sections; however, in all species except one, significant preferences for certain zones were demonstrated. High frequencies of leaf mines and galls were recorded from the middle and basal leaf sections. Apparently, the leaf apex is an unimportant microhabitat for stationary beech phyllophages, except the eriophyid Aceric stenaspis stenaspis and final leaf mining stages of the beech weevil Rhynchaenus fagi; intra‐leaf differences are discussed in relation to leaf grazing by mobile, chewing phyllophagous insects.3. The position of some abundant phyllophages in space and time is discussed. In old beech stands feeding activity is largely concentrated in the low canopy. Presumably, differences in feeding technique and position of feeding tracks of beech phyllophages on the leaf contribute to food resource partition in this canopy layer. In three congeneric eriophyid species niche diversification occurred. Further, in two cecidomyiid species phenologjcal differentiation may contribute to subdivision of food resources.
Selection for and against insecticide resistance and possible methods of inhibiting the evolution of resistance in mosquitoes
Authors: CURTIS C. F. , COOK L. M. , WOOD R. J. 
Published: March 2008

Abstract. 1. From published data on the rate of build‐up of insecticide resistance in wild populations of Anopheles culicifacies and An.stephensi, calculations have been made of the coefficients of selection which would be required to produce these rates of evolution. It is assumed in turn that the resistances might be effectively dominant, recessive or intermediate.2. The results in the case of DDT resistance in An.culicifacies indicated that the fitness of resistant individuals was 1.28–1.51 × that of susceptibles.3. Published data have also been examined with reference to the reversions towards susceptibility which occurred when spraying has been withdrawn. The coefficients of selection against resistance, which would be required to produce the observed rates of reversion, have been calculated. In the case of An.culicifacies and DDT these coefficients were found to be inversely related to the initial frequency of the susceptibility gene.4. The coefficients of selection have been used to assess the feasibility of inhibiting the evolution of resistance by spraying different insecticides in the alternate sectors of a grid pattern and/or periodically releasing susceptible males. If the proportion of migrants from sector to sector were 15–30%, a “grid” system would considerably reduce the rate of evolution of resistance, but to prevent resistance from ultimately building up to high levels periodic releases would also be required. These releases need not be frequent (approximately during one month each year) if resistance is effectively recessive in the field.
Humidity, nectar and insect visits to flowers, with special reference to Crataegus, Tilia and Echium
Authors: CORBET SARAH A. , UNWIN D. M. , PRŷS‐JONES OLIVER E. 
Published: March 2008

Abstract. 1. This paper describes field observations on diel changes in the nectars of Crataegus, Tilia and Echium in relation to microclimate and insect visits.2. Nectar concentration is highly correlated with ambient relative humidity, but the concentrative properties of the nectars differ from those of pure sugar solutions in ways that could be accounted for by microclimate or chemical effects.3. The microclimate inside flowers may influence the rate of equilibration of nectar with the relative humidity of the air, or the equilibrium concentration itself.4. The vapour pressure relationships of nectars may be influenced by the presence of components with low r/P values (that is, solutes in which solution show a relatively large lowering of vapour pressure, P, for a small change in refraction, r). Such components might be released by micro‐organisms in the nectar.5. The quantity of sugar per flower depends on the relative rates of secretion and reabsorption, among other things. The flowers we studied showed evidence for morning and evening peaks of secretion, and in Crataegus substantial quantities of sugar were ‘sequestered’ around midday.6. The pattern of visits by bumblebees to the flowers of Tilia and Echium can be related to the changing concentration of sugar in the nectar; caloric reward was probably not limiting for bumblebees visiting Tilia.
The abundance and reproductive activity of common Carabidae in a winter wheat crop
Authors: JONES MARGARET G. 
Published: March 2008

Abstract. 1. The number of common carabid beetles trapped‐irr a wheat field on a clay with flint soil from May to October in.1971–77 differed greatly: Harpalus rufipes and Pterostichus melanarius were numerous every year; but the appearance of H.aeneus, P.madidus, Agonum dorsale, Nebria brevicollis, Notiophilus biguttatus, Bembidion lampros and Trechus quadristriatus was much more variable.2. The numbers caught were not correlated with rainfall. Catches of the large species were positively correlated with accumulated temperature above an assumed activity threshold of 5°C, whereas the smaller beetles were negatively correlated with accumulated temperature, suggesting that the danger of desiccation at high temperatures limits their activity.3. The egg‐laying periods of the commonest species were: B.lampros and A.dorsale from late April to June; overwintered P.melanarius, H.rufipes and H.aeneus in May and June, with the summer generation of these species and of P.madidus from July to September; T.quadristriatus during August and September; N.brevicollis from September to November; N.biguttatus and C.fossor laid in the early summer and again in the autumn.4. A few male and female H.rufipes and H.aeneus, and one female P.melanarius and N.brevicollis were each parasitized by a single tachinid larva; one P.melanarius was infested with a mermithid parasite.
The effect of rock size upon the distribution of species of Orthocladiinae (Chironomidae: Diptera) and Baetis intercalaris McDunnough (Baetidae: Ephemeroptera)
Authors: SHELLY TODD E. 
Published: March 2008

Abstract. 1. Three experimental stream bed sections were established in areas of similar depth and current velocity to examine the effect of rock size upon the distribution of Baetis intercalaris and Orthocladiinae. Each section was composed of one rock size with the diameters (mm) of the three rock classes being 30–70, 90–140 and 160–190.2. Colonization was measured at 2 week intervals over an 8 week period, and these data were used to calculated abundance or the number of individuals per unit area of stream bed and density or the number of individuals per unit area of rock surface.3. Statistical analyses reveal that rock size was of secondary importance in determining Orthocladiinae abundance and density among the experimental bed sections. Rock size differences had a more pronounced effect upon B. intercalaris since on every sampling date both abundance and density increased with rock size.4. Rock size differences appeared to have little effect on the response of Orthocladiinae to silt deposition, whereas the reverse was true for B.intercalaris.
The distribution, abundance and host plant relationships of Salix‐ feeding psyllids (Homoptera: Psylloidea) in arctic Alaska
Authors: HODKINSON I. D. , JENSEN T. S. , MacLEAN S. F. 
Published: March 2008

Abstract. 1. Five species of psyllid occurred on seven species of Salix at Meade River, Alaska. Studies were made on the two common species Psylla pclmeni Löw and P.phlebophyllae Hodkinson. The former feeds on the phanerophy tes Salix pulchra, S.lanata, S.alaxensis and S.glauca, the latter on the chamaephytes S.phlebophylla and S.reticulata.2. Both P.palmeni and P.phlebophyllae had a 1‐year life cycle and nymphal development took place on the female Salix catkin. The life cycle was generally closely synchronized with the period of catkin development. However, only a few eggs were laid on S.glauca3. Seasonal perturbation of the host plant by flooding, ice movement and blown sand prevented psyllids breeding in certain areas colonized by the host plant.4. In P.palmenidensities and ‘feeding pressure’, measured as biomass of psyllids per gram of catkin, on the different host plants followed the sequence S.pulchra>S.lanata> S.alaxensis > S.glauca. In P.phlebophyllae densities and feeding intensities were similar onS.phlebophyllaandS.reticulataand grazing intensity was comparable withP.palmenion S.pulchra.5. A highly significant negative correlation was found between psyllid density and catkin dry weight in S.pulchra, S.phlebophylla and S.reticulata, suggesting that psyllid feeding is affecting catkin growth.6. Predation of psyllid nymphs by syrphid larvae was heavy but there was no evidence of parasitism.7. The life history strategies of the five psyllid species are discussed within the context of the constraints imposed by the arctic environment.
Radar observations of concentrations of insects above a river in Mali, West Africa
Authors: REYNOLDS D. R. , RILEY J. R. 
Published: March 2008

Abstract. 1. Radar observations are reported which demonstrate nocturnal accumulations of insects in the altitude range 30–130 m over some sections of the River Niger.2. It is shown that on occasions when individual insect tracks were resolved, the accumulations were maintained by positive insect flight manoeuvres, and were not the result of passive response to air movement.3. The mechanisms by which the insects might perceive the presence of the river are examined and it is deduced that at least some of the insects were able to detect the river boundaries by a visual or radiation sensing mechanism. It is noted that if the insects were using visual perception, their eyes must have been able to function in the absence of moonlight.4. Evidence is presented which suggests that amongst the insects which contributed to the phenomenon were Ephemeroptera, and also larger insects, the latter becoming concentrated over the river in the course of migratory flight across the area.5. Reasons why the insects accumulated over the river are discussed and it is suggested that the most probable strategies included the formation of mating swarms by some insects, and the use of the river by others as a linear feature to facilitate their orientation. It is also suggested that the insects may have been responding to differences in infra‐red radiation from the river and the bank, or to the warmer, moister air to be expected over the river.
Abundance and diversity of Homoptera in the canopy of a tropical forest
Authors: WOLDA HENK 
Published: March 2008

Abstract. 1. A series of samples of Homoptera was obtained by fogging the canopy of Luehea seemannii trees in tropical forest in the Panama Canal Zone at three different times of the year.2. The peak of abundance occurs around July (at least 11.8 individuals/m2), in the early wet season, at a time when most of the trees in the forest, including Luehea are producing new leaves.3. Minimum abundance occurs in March (at least 3.5 individuals/m2), in the late dry season.4. The samples obtained are some 35% richer in species per given number of individuals than light trap samples taken simultaneously in a similar forest some 6 km away from the present sampling site.5. The data show that the effect of intensive light trapping on the populations of Homoptera in the forest is virtually negligible.6. For a given sample size the tropical samples are many times richer in species than samples from temperate areas.
The application of X‐ray spectrometry to analysis of elemental composition (chemoprinting) in the study of migration of Noctua pronuba L.
Authors: BOWDEN J. , BROWN G. , STRIDE T. 
Published: March 2008

Abstract. 1. Wavelength dispersive X‐ray fluorescence spectrometry was used to make quantitative determinations of the elemental composition (chemoprints) of individuals and of bulked males and females of Noctua pronuba.2. Females caught in light traps at Rothamsted on two successive nights in August 1978 could be separated by significant differences in content of five elements, S, K, Ca, Cu and Zn. Two females, thought on biological grounds to be immigrants, could be distinguished from other, probably resident, females trapped at the same time.3. Males and females were different in respect of four elements, S, Cl, K and Ca, three of which, S, K, and Ca, were also discriminants between nightly populations of females.
Avian predation on the palatable butterfly, Cercyonis pegala (Satyridae)
Authors: BOWERS M. DEANE , WIERNASZ DIANE C. 
Published: March 2008

Abstract. 1. Samples from two populations of the satyrid butterfly, Cercyonis pegala were collected and analysed for palatability and incidence of avian predation.2. A series of feeding experiments indicated that C. pegala is indeed palatable.3. A high proportion of individuals in both samples showed evidence of avian attack: 10.2% in Amherst and 7.1% in Easthampton; this frequency is much higher than usually described for studies of this sort.4. The two samples showed no significant differences with respect to frequency of damaged specimens.5. There was no consistent location of damage on individuals or significant differences between the two samples.
The songs and calling sites of two European cicadas
Authors: CLARIDGE M. F. , WILSON M. R. , SINGHRAO J. S. 
Published: March 2008

Abstract. 1. The male songs of two of the commonest cicadas in southern France are described with oscillograms.2. Males of Cicada orni L. aggregate during calling whilst those of Lyristes plebeius (Scop.) space themselves out.3. Both species are widely polyphagous on trees and shrubs, but L. plebeius sings from thinner stems than does C. orni4. Such behaviour may result in the spatial separation of different species in the same habitat.
Observations on the foraging activity of Hospitalitermes umbrinus (Haviland), (Isoptera: Termitidae) in the Gunong Mulu National Park, Sarawak
Authors: COLLINS N. M. 
Published: March 2008

Abstract. 1. A single nest of the black surface‐foraging nasute termite Hospitalitermes umbrinus was studied for 5 days in July 1978. Foraging parties of workers and soldiers tend to leave the nest in a continuous stream in the evening and return carrying food balls during the following morning.2. An estimated maximum of 500000 individuals were involved in the foraging excursions. At a density of 3 nests ha‐1, the total foraging population is estimated as being at least 180 m‐2.3. The colony brought back an estimated 46.4 g (d.w.) of food in 4 days. The biomass of the colony was estimated at 349 g (d.w.) (c. 1396 g w.w.) excluding alates and the consumption at 8.3 mg (d.w.) g‐1 (w.w.) d‐1.4. The food balls were found to be of two types, light and dark coloured. The light balls contained wood constituents, bryophytes, blue‐green algae and fungal hyphae while the dark balls consisted mainly of lichens and their spores.5. Swarming began at 14.30 hours on 9 July and ended with the nuptial flight at 17.32 hours. About 3000 alates were released. They climbed to 9 m on a tree before taking off.
Population estimates and dispersal of Hydrotaea irritans Fallén
Authors: ROBINSON J. , LUFF M. L. 
Published: March 2008

Abstract. 1. Population estimates of Hydrotaea irritans were made by a mark and recapture technique at one site from 1976 to 1978.2. Population densities of five to 200 thousand ha‐1 were found with large‐scale immigration and emigration occurring from the site.3. The dispersal of marked adults from a point of release was rapid and marked flies were captured up to 3 km from the release point.4. The distribution of flies along a woodland strip was not homogeneous; certain areas appeared to be more attractive and held more flies over a period of time.5. The importance of the increasing area within which flies may be found as they move outwards from the release point is discussed.
Partitioning of resources by grassland leafhoppers (Auchenorrhyncha, Homoptera)
Authors: WALOFF N. 
Published: March 2008

Abstract. 1. Resource utilization of time (i.e. seasonal occurrence of adults) and oviposition sites (i.e. heights of the host plant above ground level) have been analysed in five species of leafhoppers commonly associated with the grass Holcus mollis.2. The d/w method proposed by May & MacArthur (1972) has been used and when the values for the two resources are examined together it becomes apparent that much potential competition for oviposition sites is reduced by segregation in time. Moreover, potential competition for common resources is reduced by mobility and dispersal of some species.