bluuebunny/crossref_metadata_2025_split huggingface dataset:
The efficiency of an insect suction sampler in grassland
Authors: HENDERSON I. F. , WHITAKER T. M. 
Published: March 2008

Abstract. 1. Capture efficiency was determined chiefly by insect type: Diptera 79–98%, Hymenoptera 60–83%, Homoptera 32–76%, Thysanoptera 27–62%, Acarina 12–40%.2. Grass length also affected efficiency, but to a lesser degree.3. Prolongation of the sampling period increased the proportions of some groups more than others.4. Capture efficiency for any group was not affected by the number of individuals present.5. Catch size did not vary with time of day.6. The method was unsatisfactory for wet grass.
Nutrient chemicals as phagostimulants for Locusta migratoria (L.)
Authors: COOK ANTHEA G. 
Published: March 2008

Abstract. 1. The phagostimulatory activity of a range of sugars, amino acids, vitamins, salts, phospholipids and sterols to Locusta migratoria (L.) was assessed singly and in combinations.2. The hexose and disaccharide sugars were shown to be highly stimulatory.3. Of the amino acids only l‐proline and l‐serine elicited feeding responses and none of the salts, vitamins, phospholipids or sterols was stimulatory when presented singly.
Relationships between feeding of Philaenus spumarius (L.) and the amino acid concentration in the xylem sap
Authors: HORSFIELD D. 
Published: March 2008

Summary. 1. P.spwnarius nymphs selected young, upper leaves of Xanthium strumarium plants, which have a relatively high amino acid concentration in the xylem sap.2. Nymphs selected or rejected a host leaf as a feeding site after a test ingestion of plant sap.3. Nymphs fed on detached leaves kept with their petioles in a solution of amino acids, in preference to leaves with petioles in a solution containing no amino acids.4. Nymphs caged on leaves with relatively high amino acid concentrations in the xylem sap suffered a lower mortality after 7 days than nymphs caged on leaves with low amino acid concentrations in the xylem sap.5. Mean excretory rate increased with the increase in the amino acid concentration in the xylem sap for third and fourth instar nymphs, and adults, but not in fifth instars.
Population densities in Drosophila obscura Fallén and D. subobscura Collin
Authors: BEGON MICHAEL 
Published: March 2008

Abstract. 1. The population densities of Drosophila obscura and D. subobscura in mixed deciduous woodland were investigated by multiple recapture techniques, marking flies with micronized fluorescent dusts.2. Approximate densities per 100 m2 were as follows: September 1974: D.subobscura males 5, D.subobscura females 31. April 1975: D.obscura males 1, D.obscura females 2; D.subobscura males 0.3, D.subobscura females 1. June 1975: D.subobscura males 6, D.subobscura females 9.3. Actual estimates have been compared using relative estimates derived from a reanalysis of Shorrocks's (1975) data.4. Throughout most of the year D.subobscura was numerically dominant, rising to a peak of 750/100 m2 in the winter; but in late spring D.obscura was dominant, having reduced winter mortality by diapausing.5. D.obscura's density was comparable with those of its Nearctic relatives; D.subobscura's was considerably higher.6. The effects of previous workers' approximations on the estimation of population parameters have been examined, and possible theoretical consequences have been indicated.
Diel activity patterns of some field Carabidae
Authors: LUFF M. L. 
Published: March 2008

Abstract. 1. A 24 h time‐sorting pitfall trap was used to collect Carabidae in a field in north‐east England in 1974, 1976 and 1977.2. Harpalus rufipes comprised 62% of the 5288 adult Carabidae caught. It was nocturnal, with an activity peak after midnight. The male activity pattern lagged behind that of females by about 1 h. The activity peak shifted to earlier in the night during September.3. Activity curves are given for eighteen other common species. Large species were all nocturnal, but a third of the smaller species were active in the day. The numbers caught of twenty‐eight less common species are tabulated and show the same trend. Overall, nearly 60% of all species caught were nocturnal and 20% diurnal; the remainder did not show a distinct pattern of day or night activity.4. A total of eighty‐two larvae of H.rufipes, Nebria brevicollis and Notiophilus biguttatus were caught, and showed similar activity patterns to those of the respective adult beetles.
Changes in the ovaries of olive flies (Dacus oleae (Gmelin)) during the summer, and their relationship to temperature, humidity and fruit availability
Authors: FLETCHER B. S. , PAPPAS S. , KAPATOS E. 
Published: March 2008

Abstract. 1. Examination of the ovaries of female olive flies (Dacus oleae) from wild populations on Corfu during the summer months of 1975 indicated that all were non‐gravid for a period of several weeks during June and July and the terminal follicles were resorbed.2. Experiments in outdoor cages indicated that olive fruits could stimulate ovarian development during the summer months.3. Experiments in constant temperature cabinets indicated that high temperatures (i. e. 26–29°C) in conjunction with a low humidity (45 ± 5°%) inhibited ovarian maturation.4. Whereas the presence of olive fruits offset the effects of temperature and humidity on ovarian development at 26°C in all flies, at 29°C very few were able to mature their ovaries.5. It is suggested that it is the interaction of temperature, humidity and access to fruit which determine when ovarian maturation ceases and recommences during the summer months.
The numbers and distribution of subterranean aphids and their exploitation by the ant Lasius flavus (Fabr.)
Authors: PONTIN A. J. 
Published: March 2008

Abstract. 1. Subterranean aphids in old pasture were found to show extremely clumped distributions with about 3000 aphids (omitting first instars) per ant nest throughout the year.2. They were generally distributed in and away from the nest mounds, but within the ant's foraging territories.3. At summer temperatures, more than 3000 first instars are lost from the aphid population per ant nest per day and it is concluded that these are eaten by the ants in addition to some older aphids and the honeydew produced.4. The aphids may therefore provide enough food to maintain the ants with very little extra needed in the form of other prey.
The food plants and feeding preferences of the beech leaf mining weevil, Rhynchaenus fagi L.
Authors: BALE J. S. , LUFF M. L. 
Published: March 2008

Abstract. 1. In laboratory experiments, R.fagi made feeding holes in eighteen tree and shrub species, including beech, from seven plant families but few plants other than beech were eaten to any extent.2. Overwintered adult weevils preferred beech to all these eighteen plants in spring.3. Hawthorn and raspberry were the most acceptable plants if beech was not available at this time.4. Field collected weevils from hawthorn had partly developed oocytes in early April, prior to beech bud burst.5. New generation weevils sought alternative food sources in late June and July; raspberry was preferred to the youngest available beech leaves at this time.
Mosquito breeding and opposition stimulant in fruit husks
Authors: LOUNIBOS L. P. 
Published: March 2008

Abstract. 1. In coastal Kenyan forests the most productive breeding habitats of Eretmapodites subsimplicipes are rain‐filled fruits of the Apocynaceae and Loganiaceae cast off by monkeys.2. Water incubated in fruit husks stimulates females to oviposit, but a sympatic congener Eretmapodites quinquevittatus, never found in fruits, prefers tap water.3. Thus, chemical discrimination of oviposition site may promote the micro‐habitat separations observed in nature.
The influence of the host plant on the population dynamics of Acizzia russellae (Homoptera: Psyllidae)
Authors: WEBB J. WARREN , MORAN V. C. 
Published: March 2008

Abstract. 1. The role of the host plant, Acacia karroo, in the population dynamics of the indigenous non‐pest psyllid, Acizzia russellae, was investigated.2. Population levels of A.russellae in early summer were almost 10 times greater on the regenerative foliage of pruned trees (cut back in spring) than on normal trees. During late summer and winter, populations declined far more slowly on pruned trees, so that very much higher numbers of psyllids were maintained on these trees through to the next spring. This finding, and others, suggest that natural enemies and climate are not major determinants in the population dynamics of this insect under normal conditions in the field.3. Laboratory measurements of several chemical and physical characteristics of the foliage of pruned and normal trees did not reveal any differences which would account for the observed effects.4. Measurements of organic nitrogen concentrations in the leaves of normal A. karroo trees in the field showed significant correlations between psyllid numbers and leaf nitrogen, but only during summer in November and January.5. Psyllid performance in the laboratory (duration of life cycle, egg production, and dry weight of emergent females) was significantly better for psyllids reared on plants containing high amino nitrogen.6. It is suggested that the availability of quantities of suitably high quality nutrients in the leaves of pruned A. karroo trees explains the “epidemic” population levels achieved by the psyllid on pruned plants. It seems that characteristics of the host plant impose the major limitation on psyllid population growth, which may explain the permanent low endemic population levels of this insect in the field.
Xylem feeding by periodical cicada nymphs on tree roots
Authors: WHITE JoANN , STREHL CHARLES E. 
Published: March 2008

Abstract. 1. Histological sections of tree roots on which periodical cicada nymphs of both the 17‐year and the 13‐year race arid various instars had fed showed that salivary sheaths made by the nymphs ended in xylem vessels.2. Because no salivary sheaths were found in phloem cells, this observation indicates that cicada nymphs are xylem feeders throughout their developmental period.3. The habit of feeding on xylem fluid, which is extremely dilute, may explain why periodical cicada nymphs require so many years (13 or 17) to mature. It may also explain why they excrete amino acids rather than sugars, as phloem feeders do.
Mimicry in the burnet mothZygaena ephialtes: population studies and evidence of a Batesian—Müllerian situation
Authors: SBORDONI V. , BULLINI L. , SCARPELLI G. , FORESTIERO S. , RAMPINI M. 
Published: March 2008

Abstract.1. Population size as well as the absolute and relative frequencies of thephegeaandfilipendulaemimetic complexes have been estimated in an area of Central Italy selected because it is: (a) little affected by man, (b) representative of many others in the Central Appennines, and (c) containing an abundant population ofZygaena ephialtes.2. This distasteful polymorphic species belongs, in Central Italy as in other Southern areas, to thephegeacomplex (Zygaena ephialtes, yellow ephialtoid form), while in Northern and Central Europe it belongs to thefilipendulaecomplex (Z.ephialtes, red peucedanoid form).3. In the Southern areas thephegeacomplex is much more abundant than thefilipendulaeone, which gives the yellow ephialtoid form ofZ.ephialtesa strong mimetic advantage over the red peucedanoid.4. In addition,Amata phegeagreatly outnumbers the other distasteful members of its complex and emerges first.5. Throughout its flight periodZ.ephialtes, which emerges about 20 days later thanA.phegea, never attains a frequency higher than 0.03 in this complex. It is suggested that in such a situation the protection that this species gains as a mimic would be very high regardless of its unpalatability.6. These findings and others discussed in the present paper, such as the degree of unpalatability, the genetics of the mimetic form as well as the polymorphism for colour and pattern, are examined according to the hypothesis of divergent evolutionary strategies in Batesian and Müllerian mimicry. It is suggested that these are meaningful concepts but that individual mimics, of whichZ.ephialtesis one, can fall between them.
An analysis of the nesting behaviour of Geotrupes spiniger Marsham (Coleoptera, Scarabaeidae)
Authors: KLEMPERER H. G. 
Published: March 2008

Abstract. 1. Female G.spiniger adults working alone made nests each consisting of a vertical shaft leading to a series of horizontal brood chambers filled with dung brood masses. Oviposition near the tip of the brood mass occurred while the egg cell was being completed over the expanded ovipositor. The shaft above each brood mass was filled with soil excavated from the next brood chamber. A similar response also filled artificial diverticula. An avoidance reaction towards buried dung prevented damage to pre‐existing brood masses.2. Virgin females did not make nests and did not avoid buried dung, but after mating (at about 4 weeks after eclosion) both types of behaviour were released within a few hours.3. The presence of dung was required to initiate but not to maintain nesting behaviour. If dung was removed after oviposition the chamber was filled with soil produced by renewed excavation. Cellulose pulp could substitute for dung in brood mass formation.4. Beetles interchanged between burrows at different stages before oviposition readily repeated all pre‐oviposition behaviour. They appeared to respond to the length of the shaft and of the brood chamber since they extended short shafts and short brood chambers considerably more than those of normal length. After oviposition the beetles continued to make brood masses even under abnormal conditions.5. Tilting the cage through 90° caused beetles before oviposition to re‐orientate their burrowing direction, but tilting just after oviposition caused them to make vertical brood masses. Placing the shaft in a horizontal position towards the end of brood mass formation postponed the termination of this phase.6. Beetles repeatedly excavated shafts and chambers when transferred to new cages. Conversely they repeatedly made brood masses when maintained in preformed plaster‐of‐Paris burrows.7. This nesting behaviour can be described as a reaction chain in which each action generates its own terminating stimulus and initiates the subsequent response. The behaviour before oviposition could be omitted or repeated as required by the environment, but after oviposition there was little response to external interference. These characteristics have direct relevance to the survival of the larvae.
The role of fungus in the diet of the leaf‐cutting antAtta cephalotes(L.)
Authors: QUINLAN R. J. , CHERRETT J. M. 
Published: March 2008

Abstract.1. The workers and queen of the leaf‐cutting antAtta cephalotesfed on the juice of swollen hyphae (staphylae) produced by their cultivated fungus, but neither obtained sufficient energy from this source for their respiratory needs. The number of staphylae eaten by workers increased with worker size but was not enough to satisfy their energy requirements.2. Larvae fed on whole staphylae and staphylae previously chewed by workers, and obtained sufficient energy from this source for respiration and growth. No evidence of feeding on fungus hyphae or of trophallaxis between worker and larvae was found. Larvae preferred staphylae to hyphae when fed them artificially and they gained more weight on the former.3. Worker ants imbibed plant sap during the preparation of plant material for the fungus garden and the uptake of carbohydrate during this process was sufficient to supply their energy needs for approximately 24 h.4. Staphylae were richer in lipid and carbohydrate, and poorer in protein than ant fungal hyphae.5. The number of staphylae produced by the fungus gardens of two small nests was comparable with the observed consumption rate but would provide only about 4% of the nest's respiratory requirements.6. In the light of these findings, a revised view of the role of the fungus in the diet of the ant is discussed.
Overwintering ecology of alpine Collembola and oribatid mites from the Austrian Alps
Authors: SØMME LAURITZ 
Published: March 2008

Abstract. 1. Collembola and oribatid mites from windswept mountain ridges at about 2700 m a.s.l. in the Austrian Alps were all killed by freezing, and depend on supercooling to survive low winter temperatures. The Collembola Tetracanthella afurcata Handschin, Xenylla acauda Gisin and Isotoma spp. collected in January had average supercooling points between ‐25 and ‐29°C, and the oribatid mites Fuscozetes fuscipes (Koch) and Lepidozetes singularis Berlese of about ‐28 and ‐31°C respectively. The ability to supercool was not increased during storage at ‐5°C, and was generally lower in species collected in March.2. The oribatid mites Fuscozetes intermedius Caroli and Maffia, F. fuscipes, Damaeus diversipilis (Willmann) and L.singularis contained from 9 to 16 μg glycerol per mg fresh weight after storage at ‐5°C, while no glycerol could be detected in the Collembola Isotoma spp., T.afurcata and Onychiurus vontoernei Gisin.3. Activity below 0°C was observed in T.afurcata and O.vontoernei, which had chill‐coma temperatures of ‐7.7 and ‐4.9°C respectively.4. Some specimens of F.intermedius survived more than 90 days of anoxia at 0°C, T.afurcata up to 60 days and O.vontoernei up to 24 days.5. The overwintering biology of Collembola and oribatid mites from the Austrian Alps appears similar to that of Norwegian species, except that those from Austria have slightly lower supercooling points and higher contents of glycerol.
Foraging byAtta sexdens(Formicidae: Attini): seasonal patterns, caste and efficiency
Authors: FOWLER HAROLD G. , ROBINSON S. W. 
Published: March 2008

Abstract.1.Atta sexdenschanges diel periods of foraging, the size of its foraging territory, the numbers and lengths of foraging trails, and its rate of foraging with respect to seasonality in subtropical Paraguay. Leaf loads are significantly larger in warmer months than loads carried in cooler months.2. Foragers segregate into three labour groups in the field: a small subset climb trees, cut large quantities of vegetation, and drop them to the ground; the second subset of foragers searches out these leaf caches, cut diem into smaller pieces, and carry and deposit the leaf fragments on the foraging trail; the third subset of workers retrieves leaf fragments on the trail and carry them to the nest.3. Pitfall trapping shows a large degree of patchiness in activity, with media workers dominating the foraging population, more so closer to vegetation which is being harvested.4. The recovery efficiency of the multi‐staged foraging behaviour is estimated to be only 49%, with the recovery of leaf caches near 50%. The impact ofA. sexdensmay, thus, be twice as great as previous estimates on their herbivory.
Aspects of host—parasitoid interactions of two aphid parasitoids, Aphidius urticae (Haliday) and Aphidius uzbeckistanicus (Luzhetski) (Hymenoptera, Aphidiidae)
Authors: DRANSFIELD ROBERT D. 
Published: March 2008

Abstract. 1. Various aspects were studied of two host‐parasitoid interactions: Aphidius urticae parasitizing the cocksfoot aphid Hyalopteroides humilis and Aphidius uzbeckistanicus parasitizing the cereal aphid Metopolophmm dirhodum. The work formed part of a study on the population dynamics of grassland and cereal aphids in Berkshire, England.2. A.uzbeckistanicus had a higher instantaneous attack rate but a slightly longer handling time than A.urticae. In both cases the functional response was curvilinear.3. A.urticae was specific to H.humilis and failed to develop in M.dirhodum. A.uzbeckistanicus could develop successfully in H.humilis but the functional response was sigmoid and the progeny were less fecund than those reared on the natural host. This species showed a clear preference for M.dirhodum when supplied with mixtures of M.dirhodum and H.humilis.4. A.uzbeckistanicus had a faster rate of development and a lower developmental threshold than A.urticae, a situation paralleled by their natural hosts.5. The results are discussed in relation to field observations. A.uzbeckistanicus may have considerable potential for reducing cereal aphid numbers. However, its preference for M.dirhodum mitigates against a reservoir being maintained in the economically unimportant grassland aphid, H.humilis.
Repeated copulation in the brown planthopper, Nilaparvata lugens Stál (Homoptera; Delphacidae)
Authors: OH ROK JING 
Published: March 2008

Abstract. 1. Mating of the brown planthopper, Nilaparvata lugens, was investigated in relation to oviposition. Females became unreceptive immediately after mating and showed various types of repelling behaviour to courting males. As a result, females usually did not mate repeatedly in quick succession, but after ceasing to lay fertilized eggs they behaved as virgins and mated again before producing more fertilized eggs.2. Copulation, followed by deposition of fertilized eggs, occurred twice, or in a few cases three times, throughout the adult stage. Copulation lasted about 2 min at the first mating and about 1 min at the second or third mating.3. When the number of fertilized eggs began to decrease rapidly, oviposition rate also decreased, but it increased again immediately after re‐mating. Repeated copulation was also related to the potential rate of population increase. In the present experiments, the estimates of net reproductive rate (R0) in brachypterous females was 287.7 (first mating), 88.3 (second mating) and 7.2 (third mating) and in macropterous females 286.8, 120.6 and 3.6 respectively.4. In a patchy environment, repeated copulation following an invasion may contribute to the increase of a population.
Cold hardiness of some Alpine Collembola
Authors: BLOCK WILLIAM , ZETTEL JÜRG 
Published: March 2008

Abstract.

Individual supercooling points ranged from ‐2 to ‐44°C for six species of springtails, five species from the Swiss Alps and one from lowland Britain. Individuals of Isotomurus alticola (Carl) and Isotoma viridis Bourlet without gut contents had substantially lower supercooling points than those containing food material.
Juveniles were more cold resistant than adults in both I.alticola and Isotoma hiemalis Schött, both with respect to supercooling point and to their survival at prolonged subzero temperatures.
Temperature and acclimation time affected the degree of supercooling of four of the Alpine species especially I.hiemalis.
Duration of culture period had no consistent influence on the supercooling potential of all the species.
Tests for glycerol in the body fluids of the five Alpine springtails were negative, but the presence of a sugar, probably glucose, together with a five carbon polyhydric alcohol was indicated by chromatography.