bluuebunny/crossref_metadata_2025_split huggingface dataset:
The distribution and abundance of the British fungal‐breeding Drosophila
Authors: SHORROCKS B. , CHARLESWORTH P. 
Published: March 2008

Abstract.

The distribution and abundance of five Drosophila species breeding in fungi are examined by attracting adult flies to baited traps and collecting fungal fruit bodies containing the larval stages.
Changes in species frequency follow a temporal (seasonal and yearly), rather than a spatial (between and within woods) pattern.
There is a regular diurnal pattern of activity in D.subobscura but not in D.phalerata. Temperature, light intensity, humidity and wind speed have no effect upon the daily activity of D.phalerata. Only temperature affects the activity of D.subobscura.
Out of 125 species of fungi collected, only forty‐eight species produced Drosophila. However, the flies are even more selective, since only five species of fungi (Phallus impudicus, Polyporus squamosus, Amanita rubescens, Pluteus cervinus and Lactarius quietus) produce 80% of all Drosophila reared.
The commonest species, D.phalerata, has two or three generations per year with a winter diapause. An outline of the yearly life cycle is given, with the major breeding sites for each generation indicated.
Measures of niche overlap calculated from the data on individual fruit bodies are very low, suggesting that the five species are effectively isolated during the larval period. This ecological isolation is achieved by a summation of several niche dimensions, woodlands, seasons, fungal species, and individual fruiting body differences.
Kleptoparasitic behaviour ofAphodius rufipes(L.) larvae in nests ofGeotrupes spinigerMarsh. (Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G. 
Published: March 2008

Abstract.Third instar larvae ofA.rufipeswere found in short vertical shafts in the soil beneath horse dung and they entered the underground brood masses ofG.spinigerwhen these occurred beneath the same deposit of dung.A.rufipeslarvae excavated shafts (60–80mm deep) beneath dung in cages. Just before diapause they burrowed down to the floor of the cage. Burrowing was inhibited in compact soil and in very dry soil. The feeding larvae were attracted to dung and to moisture and they readily attacked other larvae with their mandibles.In cages which containedG. spinigernests theA.rufipeslarvae burrowed down to feed on theG.spinigerbrood masses.G.spinigereggs and larvae did not act as attractants but they were often destroyed if theA.rufipeslarvae encountered them by chance.In cages which containedG.stercorarxusnestsA.fossorlarvae burrowed down to feed on the brood masses if no dung was provided at the surface.This non‐obligatory parasitism arises from the normal behaviour of the larvae and is usually of trivial significance, but under certain conditions the protected environment of an underground nest may favour the survival of the invading larvae.
Diel flight periodicities of some Dytiscidae (Coleoptera) associated with California rice paddies
Authors: ZALOM FRANK G. , GRIGARICK A. A. , WAY MICHAEL O. 
Published: March 2008

Abstract. Diel flight periodicities of Eretes sticticus (L.), Hygrotus medialis (LeConte), Laccophilus mexicanus atristernalis Crotch, Liodessus affinis (Say) and Thermonectus basillaris (Harris) were monitored with a rotary net machine and a black light trap. All were affected to some extent by air temperature, light intensity, and wind velocity.Most flights occur at temperatures of 23–24°C when there is no wind. Flights appear to be limited by temperatures as low as 16°C and as high as 32°C, and variously by wind velocities of 8 kph or more. The relative size and the geographical range of each species may influence its period of peak flight. Larger species tended to initiate flights later in the evening, and had a longer period during which peak flight could occur.
The effects of a fluctuating environment on the water relations of larval Lepidoptera
Authors: WILLMER P. G. 
Published: March 2008

Abstract. New techniques for haemolymph analysis under field conditions have permitted studies of short‐term changes in the body fluid concentrations of insects, in association with ambient conditions.The haemolymph of four species of caterpillar changes in relation to the prevailing relative humidity, but the magnitude of these changes was correlated with the degree of exposure to the environment characteristic of each species and instar. In larvae habitually fully exposed to ambient conditions, haemolymph concentrations normally changed predictably through a day in relation to the humidity. However, osmoregulatory mechanisms operated to keep the increments in osmolality within acceptable limits. For those larvae which inhabit protected microenvironments with constant high humidity, either in association with plants or in conspecific aggregations, ambient humidity had little effect on the blood when this was sampled in situ. But when removed from such habitats, blood osmolality increases were large and rapid, and the larvae often succumbed to desiccation.The role of biochemical, physiological, behavioural and ecological strategies in establishing the water balance of an insect in its natural surroundings are considered in the light of these findings.
Interaction of a population of the black‐kneed capsid, Blepharidopterus angulatus, and its prey, the lime aphid
Authors: GLEN D. M. , BARLOW N. D. 
Published: March 2008

Abstract.

The population dynamics of Blepharidopterus angulatus (Heteroptera: Miridae), preying on the lime aphid, were investigated from 1965 to 1974. Numbers increased or remained stable until 1969, then declined, at least intermittently. K‐factor analysis showed that the key factor was k5+6(loss of adult females, eggs and newly‐hatched nymphs).
Detailed study of numbers and mortalities from 1968 to 1971 showed that loss of adult females was the largest part of k5+6. Studies of flight activity showed most females probably emigrated from the trees before laying eggs, but k5+6 was not related to aphid numbers at the time of peak migration. However, variation in k5+6 depended on the length of time that aphid numbers remained favourable for egg‐laying.
Because of the consistently high emigration of adult females, B.anguhtus numbers increased on average by only 10% when aphid numbers favoured egg‐laying. Nett emigration was usually high, probably because the trees were isolated or in rows, with few sources of immigrants to the South‐West (direction of prevailing wind). Since the population declined by 85% in years when aphids favoured egg‐laying for ≤ 20 days, recovery would be slow after a bad year. Since 1969, 1971 and 1973 were all bad years, this explains the intermittent decline in B.angulatus numbers after 1969.
Simulation showed that neither increased numbers nor faster population growth of B.angulatus would enhance stability of predator and prey populations, but would lead to over‐exploitation of the latter. Given its low observed rate of increase, it is unlikely that B.angulatus could persist on lime at levels much above those recorded.
Adaptations to low temperature in high altitude insects from Mount Kenya
Authors: SØMME LAURITZ , ZACHARIASSEN KARL ERIK 
Published: March 2008

Abstract. 1. The strategies for low temperature survival in insects on Mount Kenya were investigated. The insects were collected from their natural habitats and their supercooling points and low temperature tolerances determined.2. Most insects showed no special adaptations to low temperature survival and seem to depend on spending the cold nights in protected habitats, such as beneath stones and fallen trunks of plants, as well as within the wet frills of dead leaves of alpine plants, where they are protected by the heat released from freezing water.3. Some insects, e.g. Collembola, aphids and a curculionid beetle, which live in relatively unprotected habitats, had low supercooling points, allowing them to remain unfrozen when exposed to low night temperatures. A nucleator free diet is apparently essential for the survival of such species.4. Two species of curculionid beetles were found to withstand freezing down to ‐7d̀C. These beetles had nucleating agents in their haemolymph and higher supercooling points than most of the other species studied.5. A moderate freezing tolerance was found in larvae of a midge that lives in the watery liquid between the leaves of Senecio brassica.
Why a cicada, Mogannia minuta Matsumura, became a pest of sugarcane: an hypothesis based on the theory of ‘escape’
Authors: ITÔ YOSIAKI , NAGAMINE MASAAKI 
Published: March 2008

Abstract. 1. Life tables were constructed for natural populations of a cicada. Mogannia minuta, during an outbreak in sugarcane fields at Okinawa to determine possible reasons for the outbreak.2. The highest mortality during the life cycle was during the beginning of the nymphal stage, and was mainly due to predation by ants.3. The estimated rate of natural increase based on a survivorship—fecundity schedule in sugarcane fields was near unity, but during the increasing period the rate was estimated to be substantially higher than unity.4. The rate of natural increase in Miscanthus‐grassland was slightly negative, suggesting that the grassland population was maintained by immigration of adults from sugarcane fields.5. Escape from predation may be the main cause of the special distribution pattern and the maintenance of extraordinarily high densities for many years.
A 9‐year study of the life cycle of Ephemera danica Müll. (Ephemeridae: Ephemeroptera) in the River Lambourn, England
Authors: WRIGHT J. F. , HILEY P. D. , BERRIE A. D. 
Published: March 2008

Abstract. 1. The life cycle of the mayfly, Ephemera danica, was studied on two contrasted sites on the River Lambourn between 1971 and 1979.2. Quantitative samples of nymphs were taken on the five major biotopes of the river bed, gravel, silt, Ranunculus, Berula and Callitriche. Exposed areas of gravel and silt held significantly lower densities of nymphs than the three macro‐phytes with their underlying substrata. The sandy substratum underlying beds of Berula frequently held significantly higher densities than the other macrophytes.3. Monthly samples from March 1971 to April 1972 followed by samples in June and December from 1972 to 1979 indicated that the nymphal phase normally took 2 years in the River Lambourn.4. All odd‐numbered years from 1971 to 1979 produced weak year‐classes. In contrast, all even‐numbered years between 1970 and 1978, with the exception of 1972, produced relatively strong year‐classes.5. Meteorological data for the period of flight activity in E.danica indicated that conditions were colder and damper in 1972 than in the other even‐numbered years of the study, when recruitment was more successful.
Effects of linear furanocoumarins on an adapted specialist insect (Papilio polyxenes)
Authors: BERENBAUM M. 
Published: March 2008

Abstract. 1. Examination of phytochemical literature reveals that a disproportionately large number of hostplants for species in the genus Papilio Section II, and in particular the machaon complex, contain linear furanocoumarins.2. Although the linear furanocoumarin xanthotoxin is known to be toxic to generalist lepidopterous larvae, it failed to affect adversely the growth and survivorship of Papilio polyxenes, a member of the P.machaon complex that feeds primarily on Umbelliferae containing furanocoumarins, when incorporated into an artificial diet.3. On the contrary, growth rate and weight gain were significantly improved in the presence of xanthotoxin.4. It is proposed, based on this experimental evidence and on hostplant utilization patterns, that furanocoumarins play a significant role in the behavioural and biochemical adaptation of Papilio species to their umbelliferous hosts.
Effects of voltinism, interspecific competition and parasitism on the population dynamics of the hemlock scales, Fiorinia externa and Tsugaspidiotus tsugae (Homoptera: Diaspididae)
Authors: McCLURE MARK S. 
Published: March 2008

Abstract.

Life tables were constructed for solitary and coexisting populations of univoltine Fiorinia externa Ferris and bivoltine Tsugaspidiotus tsugae (Marlatt) (Homoptera: Diaspididae), two exotic scale pests of eastern hemlock, Tsuga canadensis Carriere, in the northeastern United States.
Solitary and coexisting populations of F. externa had similar survivorship and population growth rates resulting in an annual increase in density of 7–16%. Survivorship of solitary and coexisting populations of T. tsugae also was similar, but growth rates differed substantially. While solitary populations increased their density by 68% annually, populations coexisting with F. extema were reduced 74% each year.
The annual reduction in T. tsugae density where it coexists with F. externa was due in part to interspecific competition which resulted in higher mortality to nymphs from dispersal and starvation and in lower fecundity of adult females relative to solitary populations. A host shift by the parasitoid, Aspidiotiphagus citrinus (Crawford) (Hymenoptera: Aphenlinidae) from F. externa to T. tsugae in autumn also accounted for 71% of the annual decrease in T. tsugae numbers. Therefore, F. externa adversely affects the growth of T. tsugae populations not only because of its superior competitive ability but also because adult para‐sitoids which emerge from it subsequently attack nymphs of T. tsugae in autumn.
Parasitism and starvation of nymphs resulting from competition were the key mortality factors in the population dynamics of these exotic hemlock scales.
The ectoparasitization ofColeophora alticolella(Lepidoptera) in relation to its aititudinal distribution
Authors: RANDALL MARTIN G. M. 
Published: March 2008

Abstract.1. The parasitization of the larvae ofColeophora alticolella. feeding onJuncus squarrosus, was investigated at a series of altitudes from 15 to 520m above sea‐level in northern England during 1977 and 1978.2. Six species of primary parasitoid and one hyperparasitoid were reared from this host. Five of the primary parasitoids were ectophagous; only two specimens of the endoparasitoid,Gonotypus melanostoma, were reared.3. All of the parasitoid species were recorded at 15 m but fewer at sites of higher altitude. Only one species,Scambus brevicomis, was recorded above 305 m, and none above 395 m. The hyperparasitoid,Tetrastichus endemus, waspresent only at 15 m.4. Percentage parasitization was highest at 15 m; it was reduced from 51% to only 2% between 215 and 305 m in 1978. There was an increase in host density over this altitudinal range.5. Three species,Scambus brevicomis. Elachertus olivaceusandEuderus viridis, accounted for most of the parasitization, but their relative proportions vaned at different altitudes.6. The sex‐ratios of the parasitoids reared fromColeophora alticolellaranged from 3.2% females forScambus brevicomis, which is considered to also use larger hosts, to 99.4% females forElachertus olivaceus, which develops by thelytokous parthenogenesis.7.Euderus viridisandScambus brevicomisstarted to attack theColeophora alticolellalarvae at a later date at 245 m than at 15 m, but attack byElachertus olivacatswas not delayed at the higher site.
An ant—treehopper mutualism: effects of Formica subsericea on the survival of Vanduzea arquata
Authors: FRITZ ROBERT S. 
Published: March 2008

Abstract. 1. The numbers of Formica subsericea (Say) were positively correlated with those of the treehopper, Vanduzea arquata Say on branches of black locust.2. The mean numbers of V.arquata on branches were greater in the second than in the first generation. However, the mean number of ants tending them was significantly lower in the second compared to the first generation.3. Defoliation of branches resulted in a reduction in the number of mem‐bracids on branches and ant numbers declined similarly.4. Survival of V.arquata was significantly greater when tended by F.subsericea than when ants were exciuded.5. Ant attendance significantly reduced the number of predators on branches with Karquata compared to branches lacking both ants and treehoppers. This, in part, explains the greater survival of V.arquata nymphs tended by ants.
The biology of the eumenid mud‐wasp Pachodynerus msidens in trapnests
Authors: JAYASINGH D. B. , TAFFE C. A. 
Published: March 2008

Abstract. 1. The biology of the eumenid mud‐wasp Pachodynems nasidens (Latr.) was studied in trapnests.2. Females nested in traps placed in the shade and some nested in the same traps from which they had emerged.3. The nesting behaviour and nest structure were generally similar to those of other eumenids that nest in borings, but a temporary crescent‐shaped plug at the nest entrance and the use of both dry soil and mud for nest‐building seems unique to P.nasidens.4. Like most other eumenids, P.nasidens collected caterpillars, mainly Pyral‐idae, Olethreutidae, Alucitidae and Thyrididae.5. In linear nests, the innermost cells contained females and the outermost cells males, resulting in proterandry. One female can make several nests, each showing proterandry.6. Female immatures were larger and took more time to develop than males. Also, their cells were larger and stocked with more food than male cells, hence needing more time to be provisioned.7. The greater ‘cost’ to produce a female and a sex ratio biased toward females in short traps and about unity in longer traps, leads to a comment on parental investment.
On the failure of two butterfly species to respond to the presence of conspecific eggs prior to oviposition
Authors: SINGER MICHAEL C. , MANDRACCHIA JOANNE 
Published: March 2008

Abstract. 1. The eggs of Euptychiine butterflies are laid singly, but their distributions tend to be contagious. However, these insects do not discriminate between egg‐laden and egg‐free plants.2. Response to conspecific eggs is not part of the mechanism responsible for clumped egg distribution.
Patterns of parasitism by insect parasitoids in patchy environments
Authors: HASSELL M. P. 
Published: March 2008

Abstract. 1. This paper shows how the different spatial patterns of per cent parasitism in patches of different host density can be explained within a single model framework that takes into account the parasitoid's aggregative response, and the factors limiting the degree of host exploitation within patches.2. Two contrasting laboratory examples are presented in which the distribution of searching parasitoids and the resulting levels of parasitism in different patches are both known for a range of parasitoid densities.3. A model is described predicting the number of hosts parasitized per patch, in which the number of parasitoids searching is determined from a simple expression allowing different degrees of aggregation.4. The model generates patterns of parasitism encompassing the two laboratory examples and a wide range of examples from the field.5. The importance of density dependent spatial distributions of parasitism to population stability is briefly discussed.
Wind dispersal and settling of first‐instar crawlers of the cochineal insect Dactylopius austrinus (Homoptera: Coccoidea: Dactylopiidae)
Authors: MOW V. C. , GUNN B. H. , WALTER G. H. 
Published: March 2008

Abstract. 1. The efficiency of D.austrinus as a biological control agent depends on successful colonization of the cactus weed Opuntia aurantiaca.2. Unlike other coccoid insects, the female crawlers (first‐instar larvae) of cochineal insects develop long wax fiaments on the dorsal surface of the body that reduce their terminal velocity in air and enhance wind dispersal.3. Dactylopiid males are dispersed as winged adults and male crawlers of D.austrinus have fewer and shorter filaments than the females and they are blown a shorter distance in a wind tunnel.4. Vertical and horizontal wind dispersal of D.austrinus from O.aurantiaca in the field is usually very limited, but was greatly improved when crawlers were launched from an elevated ‘tower’.5. Preparatory to dispersal, female crawlers climb to the top of the host plant and ‘take‐off’ from there. This behaviour is most marked in crawlers 2–3 days old at which stage the wax filaments are best developed: the behaviour is never manifest following artificial ‘dispersal’.6. Final settling on cladodes of the host plant is a function of the age of the female crawlers and of the condition of the cladodes.7. When given a choice, approximately equal numbers of crawlers settled on cladodes that had received high and low fertilizer treatments. More crawlers settled on cladodes that had been kept in the shade than on those kept in the sun, and on basal rather than terminal cladodes.8. The highest percentage of crawlers settled on cladodes that were 20% dehydrated. Settling success was much lower on more desiccated cladodes.
Survivorship of the sexual and agamic generations of Andricus quercuscalicis on Quercus cerris and Q.robur
Authors: COLLINS M. , CRAWLEY M. J. , McGAVIN G. C. 
Published: March 2008

ABSTRACT.

Survivorship within the galls of the sexual and agamic generations of Andricus quercuscalicis (Burgsdorf) is estimated from field populations.
The sexual generation on Turkey oak suffers a 20% death rate through parasitism by Mesopolobus spp. The emerging parasitoids are virtually all males.
The agamic generation on the acorn cups of English oak is not attacked by any parasites or inquilines at our Berkshire site despite the fact that most of the species which parasitize the gall in continental Europe are on the British list.
Agamic galls cause average losses of between 30% and 50% of the total acorn crop in different years. Individual trees differ greatly in their rates of loss, many losing over 90%, others losing virtually none.
Absence of wing polymorphism in the arboreal, phytophagous species of some taxa of temperate Hemiptera: an hypothesis
Authors: WALOFF N. 
Published: March 2008

ABSTRACT.

Most arboreal Cicadellidae (Homoptera) and the arboreal, phytophagous Heteroptera are macropterous and capable of flight.
The low incidence of flightless morphs in the above insects is compared with its frequency in the species living on low vegetation.
It is suggested that in spite of the permanence of arboreal habitats, the almost complete absence of flightless morphs in these groups of the temperate Hemiptera is related to the architectural complexity of trees.
Larval aestivation and direct development as alternative strategies in the speckled wood butterfly, Pararge aegeria, in Sweden
Authors: WIKLUND CHRISTER , PERSSON ANN , WICKMAN PER OLOF 
Published: March 2008

ABSTRACT.

Sweden has two disjunct populations of the speckled wood butterfly, Pararge aegeria L. The southern population has two generations per year but the central Swedish population is univoltine. When rearing larvae from central Sweden under normal photoperiodic conditions but at temperatures slightly above the ambient, 42% of the larvae developed directly and produced a second generation of adults the same summer. The egg—larval development time of the directly developing individuals was about 40 days, whereas that of the individuals developing along the univoltine pathway was about 100 days.
Larvae of the central Swedish population normally aestivate during part of the summer even though abundant food is available. In the closely related Lasiommata petropolitana F., which is the only Swedish satyrid that overwinters in the pupal stage besides P.aegeria, larvae do not aestivate, indicating that there does not seem to be any obligatory association between pupal hibernation and larval aestivation.
Development rates of aestivating and directly developing P.aegeria are equal up to the third larval instar. During the third and fourth instars, however, the development rate of aestivating individuals is retarded and females also have an additional fifth instar.
Since the central Swedish P.aegeria have the capacity to develop directly, and the southern Swedish ones have the capacity to aestivate, the evidence indicates that the outcome of the cost/benefit balance of univoltine versus bivoltine development differs between the two areas.