bluuebunny/crossref_metadata_2025_split huggingface dataset:
Larval densities and a life‐table for the gypsy moth, Lymantria dispar, estimated using the head‐capsule collection method
Authors: HIGASHIURA YASUTOMO 
Published: March 2008

ABSTRACT. 1. In order to estimate the absolute larval density in each stage of a larval population of the gypsy moth, Lymantria dispar L., in a deciduous forest in northern Japan, the head‐capsule collection method was used. An estimate by this method was compared with estimates based on two kinds of frass collection methods.2. Twenty‐one traps made of cloth were put in a study plot. Each trap was of 24.5 cm diameter. Larval head‐capsules falling into the traps were collected and sorted by hand. On the first sampling occasion, the population was also estimated using the frass‐collection method.3. Larval numbers estimated by the head‐capsule collection method were almost identical to estimates by the two frass methods. Larval numbers entering the four larval instar were successfully estimated by the head‐capsule collection method, and an age‐specific life table was established using the resultant estimates.
Overwintering survivorship of pupae of the mimosa web worm, Homadaula anisocentra (Lepidoptera: Plutellidae), in an urban landscape
Authors: MILLER FREDRIC D. , HART E. R. 
Published: March 2008

ABSTRACT. 1. Overwintering survivorship of pupae of the mimosa webworm, Homadaula anisocentra Meyrick (Lepidoptera: Plutellidae), was examined in several urban habitats in central Iowa during the winters of 1981–82, 1982–83 and 1983–84.2. Survivorship and supercooling point temperatures were determined throughout the winters. Corroborative laboratory studies were conducted during the winter of 1982–83.3. Minimum ambient temperatures that equalled or were below the supercooling point of the insect, at any time, were lethal.4. Prolonged cold exposure below 0°C and above the supercooling point resulted in high mortality levels. To quantify this relationship, a concept of minimum‐temperature exposure was developed by tabulating the number of degrees that the daily minimum temperature was below 0°C for a given sampling period.5. Some mimosa webworm pupae were found to overwinter in highly protected sites (2.5–5.0°C warmer than the ambient air temperatures) in the urban environment, resulting in less minimum‐temperature exposure and reducing the probability of reaching the lethal supercooling point temperature.
Guild structure of arthropods from Bornean rain forest trees
Authors: STORK N. E. 
Published: March 2008

ABSTRACT. 1. 23275 arthropods collected by insecticide fogging from ten Bornean lowland rain forest trees were sorted to approximately 3000 species and assigned to guilds using two sets of criteria.2. The rank order for proportions of guilds of species but not individuals is similar in tropical and temperate canopy samples.3. Misplacement in the guild assignments of a few species can cause important differences in the proportions of certain guilds. This can seriously affect the results of comparisons of different samples, and views on proportional constancy of guilds of species on different trees.4. Guilds of arthropod species such as chewers, suckers, all phytophages, predators, ants and tourists, occur in constant proportions in samples from different tropical trees and this constancy of proportion is similar in samples from groups of‘closely related’and‘distantly related’trees.5. The guild concept of community structure and problems in assigning species to guilds are considered with respect to arthropod samples. The conclusions on constancy of proportion for guilds of species are tempered by remarks on the problems of guild composition.
Ecological correlates and heritability of reproductive variation in two co‐occurring grasshopper species
Authors: ATKINSON DAVID , BEGON MICHAEL 
Published: March 2008

ABSTRACT. 1. Relationships are examined between mean egg size and possible selection pressures acting on two grasshopper species, Chorthippus brunneus (Thunb.) and Myrmeleotettix maculatus (Thunb.), co‐occurring at three sites in a sand dunes area.2. Heavy eggs were laid where the mean crowding of hatchlings was high in relation to the amount of grasses with thin‐edged leaves. To a lesser extent, large eggs were also found in more desiccating conditions. Mean egg dry weights did not correlate with measures of crowding or measures of crowding in relation to total grass abundance.3. Significant differences in egg size and clutch sizes were observed between the stocks of second generation, laboratory‐reared M.maculatus from three study sites. The significant difference in egg size (site 2 stock > site 1 stock) ran counter to the difference observed in the field but the difference in clutch size (site 3< site 2) was consistent with that observed between field populations.4. We argue that egg size is primarily determined by selection pressures on the size of hatchlings but that predictably poor feeding conditions for juveniles and adults at site 2 results in the production of smaller adults which, in M.maculatus, then lay smaller eggs. We further argue that M. maculatus from site 2 have been selected to lay larger eggs for their body size and body condition in order to compensate partially for this environmental constraint.
Geographical variability in, and temperature effects on, the phenology of Maniola jurtina and Pyronia tithonus (Lepidoptera, Satyrinae) in England and Wales
Authors: BRAKEFIELD PAUL M. 
Published: March 2008

ABSTRACT. 1. Geographical variability in, and temperature effects on, the mean date of adult flight period and the SD about this date are analysed for two univoltine, grassland butterflies in England and Wales from 1976 to 1985. Data were collected on the Butterfly Monitoring Scheme for Maniola jurtina (L.) at twenty‐nine sites and Pyronia tithonus (L.) at twenty sites.2. Substantial variability for mean date and SD occurs between years and between sites. Changes in mean date between years tend to occur consistently at different sites. The species show some parallel in variation between sites, especially for mean date.3. June maximum temperature accounts for 95% and 75% of the variation in mean date between years in M. jurtina and P. tithonus, respectively (r=‐0.97 and ‐0.87). Similar relationships occur for temperatures cumulated over the period of post‐winter development from March to July or August.4. Greater geographical variability in phenology, and a generally less synchronized flight period in M.jurtina may be associated with broader habitat preferences than in P. tithonus.5. The mean date of adult flight period remains at roughly the same date at more northerly latitudes. In M.jurtina the flight period becomes more synchronized, begins later and ends earlier in the north. P. tithonus shows little or no indication of such a response to latitude. This is discussed with regard to changes in season length and factors limiting the species’range.
Long adult life, low reproduction and competition in two sub‐Antarctic carabid beetles
Authors: DAVIES L. 
Published: March 2008

ABSTRACT. 1. On the biologically impoverished sub‐Antarctic Ile de la Possession, Iles Crozet, Amblystogenium pacificum Putzeys and A.minimum Luff (Carabidae), both opportunistic carnivores, coexist in fellfield habitat above 120 m altitude, where they hunt prey in inter‐stone spaces.2. Beetles show marked claw wear showing that many individuals survive to breed in their third or later year of adult life, and in some years, particularly in A.minimum, populations consisted largely of very old beetles. This coupled with evidence from ripe egg numbers, of rarity of tenerals and of larvae, shows that adult recruitment rates were usually very low.3. In fellfield the coexisting species pair have non‐overlapping size distributions with A.pacificum the larger. In moorland A.pacificum adults occur in isolation and are smaller and overlap the size ranges of both species in fellfield. These facts are interpreted as character displacement or release, reflecting present‐day interspecific competition, probably for food. Supporting evidence was obtained in terms of apparent size‐differential survival of beetles of different ages.
The causes of seasonal changes in numbers of the yellow dung fly, Scathophaga stercoraria (Diptera: Scathophagidae)
Authors: GIBBONS D. S. 
Published: March 2008

ABSTRACT. 1. Counts of adult Scathophaga stercoraria (L.) on cow pats were made in Houghall, County Durham, in 1964 and 1965.2. A spring peak of numbers was due to adults (overwintered mainly as pupae or larvae) maturing and going to dung to breed. Numbers then dropped, rising to one or more peaks in late June—early July. In 1964 there was then a summer drop in numbers until late September. In 1965 high numbers persisted in summer associated with cooler, wetter weather. Autumn peaks in both years persisted until severe frosts or snow.3. Mature adults, developed from eggs laid during the spring peak, form the first generation when breeding in mid‐late June. No clear generations can be identified after this, due to eggs being laid daily (females have successive gonotrophic cycles). Changes in adult numbers breeding reflects survival of eggs and newly‐hatched larvae 5–6 weeks earlier, and lower survival rates of adults in mid‐summer compared with spring and autumn.4. Adult Scathophaga numbers in vegetation rose as numbers on dung dropped. Females dissected to count ovariole tunica dilatations showed that most flies in vegetation were immature, with some parous flies hunting insects to develop the next batch of eggs.5. Females on dung were dissected and found to range from immature to seven‐parous. Those gravid for the first time were grossly under‐represented, possibly due to wider dispersal.6. It is suggested that seasonal changes in this r‐strategist cannot be explained simply in terms of generations nor by the occurrence of adult diapause.
Effects of reproductive timing and colony size on the survival, offspring colony size and drone production in the honey bee (Apis mellifera)
Authors: LEE PHILIP C. , WINSTON MARK L. 
Published: March 2008

ABSTRACT. 1. The effects of colony size and time of reproduction on the survival and size of offspring colonies and on drone production were examined for honey bees, Apis mellifera L. Drone and worker production and survival of parental and offspring colonies were monitored following swarming. Also, the temporal patterns of drone emergence and availability of unmated queens were examined.2. Colony size at swarming was positively correlated with the number of workers invested in offspring colonies and the number of queens produced. However, colony size at swarming was not correlated with the number of offspring colonies produced.3. Swarm size was positively correlated with drone and worker production after swarms were hived. Worker production of hived swarms was positively correlated with colony survival. Offspring queens which inherited a parental nest survived longer than queens in either primary swarms or afterswarms, presumably due to the advantage of inheriting a nest.4. Drone emergence peaked just prior to swarming, the time when unmated queens were available. High drone production by colonies initiated by swarms probably reflected an attempt to reproduce prior to winter. The probabilities of a second swarming cycle within the same year and of surviving the winter were low for colonies initiated from swarms.
Diel patterns of activity of Thymelicus lineola adults (Lepidoptera: Hesperiidae) in relation to weather *
Authors: PIVNICK KENNETH A. , McNEIL JEREMY N. 
Published: March 2008

ABSTRACT. 1. Daily patterns of activity, thoracic temperature (Tth) and thermoregulatory behaviour in relation to environmental conditions were studied in the European skipper Thymelicus lineola (Ochsenheimer) adults.2. Daily activity was limited mainly by Tth, which in turn was dependent on air temperature (Ta) and sunlight. However, when light intensity fell to < 100 W m−2, skippers also became inactive.3. Tth was sometimes as much as 12°C above Ta, and this was most pronounced under cool conditions when basking activity predominated.4. Black globe temperature (Tbg) which, in the absence of wind, is influenced by both Ta, and radiant heat load in a manner similar to a basking butterfly, was used to approximate the maximum Tth attained by T.lineola through basking.5. Both males and females basked at Tbg >20°C, and if this temperature was not attained, skippers remained inactive. As Tbg increased, basking activity declined more rapidly in males than in females. Basking bouts were also shorter in males.6. Males also flew, fed and courted females at Tbg >20°C, while females only fed and flew at Tbg >22°C. The percentage of both sexes feeding and flying, and courting in the case of males, were positively correlated with Tbg.7. In warm weather, males divided their time equally between flying and feeding, while females spent the majority of their time feeding. Feeding bouts were shorter and flying bouts were longer in males than in females. Flight duration in males was positively correlated with Tbg.8. Skippers avoided, and, consequently laid fewer eggs in, shady areas.9. Sexual differences in activity patterns in relation to weather reflect differences in the reproductive requirements of the two sexes.
Ecological methods for adult populations of Oryctes rhinoceros (Coleoptera, Scarabaeidae)
Authors: ZELAZNY B. , ALFILER A. R. 
Published: March 2008

ABSTRACT. 1. For comparing assessment methods, O.rhinoceros (L.) populations were monitored in five 30–50 ha plots in southern Luzon, Philippines. No consistent correlations were found between number of beetles caught in traps, amount of palm damage and number of breeding sites. Apparently, plots were too small to account for fast dispersal of beetles.2. Coconut cap traps baited with ethylchrysanthemumate attracted O.rhinoceros adults searching for breeding sites. Several factors were identified influencing catches but trapping was found to be unsuitable for accurately assessing pest populations.3. A new method which gives estimates on the monthly number of O.rhinoceros attacks on coconut palms, was tested in the Maldives. Palms are climbed about once a year and the sequence of fronds, the number and the position of beetle cuts are recorded.4. Reduction with age of the length of three teeth on the fore tibia of O. rhinoceros adults was studied in the Philippines. The data was insufficient to obtain a clear correlation between age and length of teeth.5. The observations indicated that in the Philippines after leaving their site of pupation, O.rhinoceros adults spend about 5 weeks feeding on coconut palms. This is followed by a period of about 7 weeks in breeding sites and, on occasion, additional visits to palms. With these estimates it was possible to relate palm damage records with numbers of feeding adults.
Size and fecundity in the Jamaican gall‐midge Asphondylia boerhaaviae
Authors: FREEMAN B. E. , GEOGHGEN ANDREA 
Published: March 2008

ABSTRACT. 1. The gall‐midge Asphondylia boerhaaviae Möhn galls weeds belonging to the Nyctaginaceae in Jamaica and other parts of the Caribbean. The species breeds throughout the year with a generation length of < 1 month.2. In adult females, plots of wing length on hind tibial length, of maximum potential fecundity (m.p.f.) on wing length, and of m.p.f. on ovariole number, suggested the presence of a small morph, which the use of discriminant function analysis and other investigations confirmed. There was also good evidence of two size morphs in adult males.3. Both body size and ovariole number had significant effects on m.p.f. but these effects were different in the two morphs. While the food plants had significant influences on size and fecundity, these were relatively small. The m.p.f. of the small morph was 125.8±11.1 eggs, and of the large morph 318.7±8.3 (95% cl).4. Laboratory experiments on the flight performance of newly‐emerged midges indicated that the small morph was not dispersive and that about 80% of the large morph was dispersive. No differences in size, wing length or fecundity could be found between the two behavioural types of the large morph.5. The nature of the polymorphism is unusual, particularly since the dispersive individuals potentially have similar (or greater) fecundity than the non‐dispersive ones.6. Estimates of achieved fecundity (eggs actually laid, rather than m.p.f.) were 67.8±9.6 (field, minimum) and 138.9±30.4 (laboratory), the latter estimate being based on large‐morph females.
Seasonal variation in the reproductive strategy of the parasitic wasp Eulophus larvarum (Hymenoptera: Chalcidoidea: Eulophidae)
Authors: GODFRAY H. C. J. , SHAW M. R. 
Published: March 2008

ABSTRACT. 1. Eulophus larvarum (L.) (Hymenoptera: Eulophidae) is a gregarious parasitoid of lepidopterous larvae feeding on broad‐leaved trees. Normally there are two generations a year.2. Sex ratio in the spring generation of larvae is female biased. The bias is probably due to local mate competition as progeny from one brood emerge from their pupae in close proximity to each other.3. Sex ratio in the summer generation of larvae is near equality. Local mate competition is absent as individuals from the same brood become separated during the winter.4. Variation in sex‐ratio in the spring generation is consistent with a binomial model. Variation in sex ratio in the summer generation is much greater than expected from a binomial model and there is a large proportion of single‐sex broods.5. Two hypotheses are put forward to explain the summer generation pattern: virgin oviposition, and strong intersexual competition.6. No differences in clutch size were found between the two generations.
Insect‐induced chemical changes in young lodgepole pine (Pinus contorta): the effect of previous defoliation on oviposition, growth and survival of the pine beauty moth, Panolis flammea
Authors: LEATHER S. R. , WATT A. D. , FORREST G. I. 
Published: March 2008

ABSTRACT. 1. Significantly more eggs were laid by adult female pine beauty moths (Panolis flammea (D&S)) on previously undefoliated lodgepole pine (Pinus contorta Douglas) saplings than on those which had been partially defoliated the year before.2. The larval weights, mean relative growth rates and survival rates of P.flammea were lower on defoliated trees than on undefoliated trees.3. Marked and significant differences between the monoterpene profiles of the shoot cortical oleoresin of defoliated and undefoliated trees were linked to oviposition preferences in P.flammea.4. Differences occurred between the levels of soluble tannins in previously defoliated and undefoliated trees.5. The results are discussed in relation to earlier work on insect‐induced changes in plants, and the significance of inter‐provenance differences in lodgepole pine response is assessed.
Communication of leaf suitability by gregarious eastern tent caterpillars (Malacosoma americanum)
Authors: PETERSON STEVEN C. 
Published: March 2008

ABSTRACT. 1. Previous work has shown that leaf age affects recruitment trail marking by eastern tent caterpillars (Malacosoma americanum Fabr.). Young leaves of host plants elicit trail marking to a greater degree than mature leaves.2. Experiments were conducted to establish the relationship between the differential behavioural responses of larvae to young and mature leaves and the suitability of foliage for larval growth and survival. Foliage of black cherry (Prunus serotina Ehrh.), a typical rosaceous host plant, was used for this comparison.3. Larvae preferred young leaves to mature leaves in choice tests, and marked more to young leaves than to mature leaves in no‐choice tests.4. Mature leaves supported adequate growth through two larval instars of rearing, but thereafter were unsuitable for growth. Larvae fed mature leaves had lower pupal weight, poorer survival, and grew less efficiently than larvae fed young leaves.5. The results support the hypothesis that the trail communication system of eastern tent caterpillars is an adaptation to efficiently locate leaves which are favourable for larval growth and survival.
Host‐habitat location by Apanteles glomeratus and effect of food‐plant exposure on host‐parasitism
Authors: SATO Y. , OHSAKI N. 
Published: March 2008

ABSTRACT. 1. The study investigates differences in the oviposition pattern of a braconid parasitoid, Apanteles glomeratus L., in three Pieris species in Japan in relation to their use of different cruciferous foodplants.2. A.glomerutus females located various habitats of different crucifers. On field crops and exposed wild crucifers P.rapae crucivora Boisduval and P.napi japonica Shirôzu, which are both physiologically suitable hosts, were attacked at a high rate, although P.n.japonica is rare in such situations, while P.melete Ménétriès, which is a physiologically unsuitable host, was attacked slightly less frequently.3. When P.n.japonica occurred on crucifers hidden by overshadowing vegetation, as it generally did, it suffered a very low level of parasitism by A.glomeratus, but if the overshadowing vegetation was cleared then a high rate of parasitism ensued.4. The foodplant concerned, Arubis, was attractive to the parasitoid and not deleterious to its development in P.n. japonica, but it was not used by P.r.crucivora, which usually failed to develop on it under experimental conditions.5. The parasitoid females could not locate foodplants hidden by overshadowing vegetation. Therefore the most important difference between foodplants in host‐habitat location was the situation in which the foodplant grew.
Competition between two parasites of the Florida red scale in Israel
Authors: STEINBERG SHIMON , PODOLER HAGGAI , ROSEN DAVID 
Published: March 2008

ABSTRACT. 1. During the last decade, the endoparasitic wasp Pteroptrix smithi (Compere) has gradually replaced the ectoparasitic wasp Aphytis holoxanthus DeBach on the Florida red scale, Chrysomphalus aonidum (L.), on citrus in Israel. The studies reported herein were aimed at elucidating some of the mechanisms of this process.2. Aphytis adults detected, and were attracted to hosts containing eggs of Pteroptrix, whereas adults of Pteroptrix did not detect hosts containing eggs of Aphytis. In this extrinsic aspect of host discrimination, Aphytis is superior to its competitor. Neither species responded to hosts containing heterospecific first‐instar larvae, and both tended to avoid hosts containing more advanced developmental stages of the other species.3. Aphytis outcompeted Pteroptrix in most cases of multiple parasitism, as observed under both controlled and field conditions.4. Aphytis was superior in mixed‐species cultures; however, its dominance was affected by the availability of adult food.5. Aphytis adults were found to be more sensitive (×4.11) to the insecticide malathion as compared to adults of Pteroptrix. This finding provides a possible explanation to the displacement of Aphytis by Pteroptrix in the citrus groves along the coastal plain of Israel.