bluuebunny/crossref_metadata_2025 huggingface dataset:
Low circulating IGF‐I levels in hyperthyroidism are associated with decreased GH response to GH‐releasing hormone
Authors: Ramos‐Dias João C. , Yateman Martin , Camacho‐Hübner Cecilia , Grossman Ashley , Lengyel Ana‐Marla J.
Published: March 2008

OBJECTIVE Several abnormalities In the GH response to pharmacological stimuli have been described in hyperthyroidism. Both normal and high serum IGF‐I levels have been reported, as well as a decrease in IGF‐I bioactivity. We have evaluated the GH response to GH‐releasing hormone (GHRH) in hyperthyroid patients and the effects of hyperthyroidism on serum IGF‐I levels. The possible relations between nutritional status, thyroid hormones and IGF‐I levels were also investigated. We also studied the influence of long‐term β‐adrenoceptor blockade on the GH response to GHRH In these patients.

DESIGN In 18 hyperthyroid patients and In 12 control subjects, GHRH (100μg) was administered as an i.v. bolus injection. Eight hyperthyroid patients and 8 control subjects received 50 μg GHRH i.v. Seven hyperthyroid patients were reevaluated after β‐adrenoceptor blockade. IGF‐I and albumin levels were measured Initially in all hyperthyroid patients and control subjects. Body composition was determined in 11 hyperthyroid patients and in a group of 33 matched normal controls.

PATIENTS Hyperthyroid patients were compared to control subjects.

MEASUREMENTS GH, TSH and free 14 were measured by Immunofluorometric assay. IGF‐I, total T3 and total T4 were measured by radioimmunoassay. Body composition was determined using a dual‐energy X‐ray absorptfometer.

RESULTS The GH response to 100 μg GHRH in hyper thyroid patients was blunted compared to control subjects. The mean peak GH levels and the area under the curve were significantly lower in hyperthyroid patients compared to control subjects (11 ± 1 vs 27 ± 5 μg/l and 820 ± 113 vs 1879 ± 355 μg/l 120 min, respectively; P <0.01). IGF‐I levels were significantly reduced in hyperthyroid patients compared to controls (131 ± 10 vs 201 ± 16 μg/l, respectively; P <0.01). Ideal body weight, serum albumin levels and the lean body mass were also reduced In hyperthyroid patients. After β‐adrenoceptor blockade there were no changes in the blunted GH response to GHRH in hyperthyroid patients.

CONCLUSION Our data suggest that the blunted GH response to GHRH In hyperthyroidism is apparently not related to circulating IGF‐I levels. It is possible that nutritional factors could play a role in the reduced circulating IGF‐I levels found In these patients.
A gonadotrophin dependent stromal luteoma: a rare cause of post‐menopausal virilization
Authors: Chico A. , García J. L. , Matías‐Gulu X. , Webb S. M. , Rodríguez J. , Prat J. , Calaf J.
Published: March 2008

A stromal luteoma Is an uncommon ovarian tumour in post‐menopausal women, which presents rarely with hyperandrogenism and virilization. We present the case of a 64‐year‐old woman referred for evaluation of virilization which had developed over 5 years. Testosterone, FSH and LH were markedly inhibited following the administration of a GnRH analogue, suggesting a gonadotrophin dependent, testosterone secreting ovarian tumour, which could not be localized with Imaging techniques. Surgery revealed normal sized ovaries with no apparent lesions, but microscopic examination showed a small stromal luteoma In the right ovary and severe stromal hyperthecosis In the adjacent and contralateral ovarian stroma. We conclude that stromal luteoma is an uncommon cause of virilization in post‐menopausal women. This case illustrates, to our knowledge for the first time, that a stromal luteoma is not autonomous but is gonadotrophin dependent.
Studies on the biology and distribution ofLeptinus testaceusMüller within a community of mixed small mammal species
Authors: BUCKLE ALAN P.
Published: March 2008

In a mixed small mammal communityL.testaceuswas found to infestA.sylvaticusmore frequently than eitherC.glareolusorM.agrestis.

Male and female rodents carried similar numbers of the beetle.

Peak infestation onA.sylvaticusoccurred during spring and summer suggesting a single major emergence period.

There was good correlation between the beetle index and the numbers of individuals ofA.sylvaticusinfested; this relationship resembled that found within certain host/ectoparasite relationships.
Reconstructing ancient ecological conditions from insect remains; some problems and an experimental approach
Authors: KENWARD HARRY K.
Published: March 2008

Analysis of insect ‘death assemblages’ from ancient natural and anthropogenic deposits can provide valuable information about conditions in the past but the theoretical basis of such investigations is weak, especially with respect to the quantification of habitats on archaeological sites.

Evidence is presented for the existence of a transported component, termed ‘background fauna’, in death assemblages, as well as the remains of insects derived from the immediate surroundings.

The background component is derived principally from airborne insects and from bird droppings and may seriously detract from the accuracy of reconstructions of past ecological conditions. Factors affecting its relative importance are discussed.

As well as including species from distant habitats, the background fauna may be biased in favour of species from temporary habitats.

Some solutions to the problems presented by the background fauna are discussed. A high proportion of a species or ecological group will usually be evidence that its habitat existed near to the deposit enclosing the fauna, although there may be exceptions.

The structure of the background rain of insects has probably altered with changes in town and countryside brought about by man. Attempts to recognize background fauna in ancient assemblages must take account of this.

Many ancient assemblages, especially if small, will give no useful ecological information.
Studies on a population of large termite mounds in Uganda
Authors: POMEROY D. E.
Published: March 2008

Two study‐sites near Kampala were mapped and all of the termite mounds within them were measured. Changes were recorded in the three succeeding years. A method was developed for estimating mound volumes from height and diameter.

Macrotermes bellicosus mounds reached a volume of about 2.4 m3 in 3 years after which they grew more slowly to a maximum from 4 to 6 m3. Growth in volume during the first 3 years was approximately linear and its rate did not vary seasonally, probably because growth is related to temperature which was nearly constant throughout the year.

M.bellicosus mounds had an average length of life of about 10 years, although colonies survived on average only 4 years. The corresponding figures for Pseudacanthotermes spp. were 5 and 2 1/2 years. Some mounds were recolonized after the death of the original colony.

Fresh earth was brought up at a minimum rate of about 10 m3 ha‐1 yr‐1 but more was lost by erosion and destruction and the populations of mounds were decreasing.

The number of ventilation shafts in M.bellicosus mounds increased with the volume of the mound. Many mounds, both dead and alive, supported vegetation.

Local opinion is that Pseudacanthotermes are harmless but M.bellicosus is regarded as a pest and attempts are made to destroy its mounds.
The role of predator‐prey size ratio in determining the efficiency of capture by Anthocoris nemorum and the escape reactions of its prey, Acyrthosiphon pisum
Authors: EVANS H. F.
Published: March 2008

Laboratory experiments are described which give the efficiency of Anthocoris nemorum in capturing its aphid prey Acyrthosiphon pisum. The efficiency of capture increases as the predator‐prey size ratio increases. The relationship holds through all the anthocorid developmental stages.

Aphid escape reactions are made up of three basic components; kicking, walking or dropping off the plant. These reactions are all related to the predator‐prey size ratio. Kicking is most successful at small ratios while dropping is most successful at high ratios. Walking occupies an intermediate position but has a generally lower probability of success.
An emergence trap for bark‐dwelling insects, its efficiency and effects on temperature
Authors: GLEN D. M.
Published: March 2008

A cloth cage with collecting bottles is described for trapping adult insects emerging from beneath tree bark in low densities.

The traps had little effect on temperature, although fluctuations tended to be slightly damped. They probably delayed emergence of adult codling moth, Cydia pomonella by a day or two only.

In a test of trap efficiency, all codling moths which developed to the adult stage inside the traps were recorded in the collecting bottles; a few larvae remained in diapause, and the proportion of these was greater in the traps than in an outdoor insectary, so that traps tend to provide a slight underestimate of adult numbers.
Synoptic weather conditions inducing long‐distance immigration of planthoppers, Sogatella furcifera Horvath and Nilaparvata lugens Stal
Authors: KISIMOTO R.
Published: March 2008

Adults and nymphs of Sogatella furcifera and Nilaparvata lugens are serious pests of growing rice in Japan. They appear in June and July but their origin was unknown. Inflow of warm and humid air from the south was shown to favour the appearance of planthoppers. The air inflow was associated with the passage of depressions along the frontal zone, called Bai‐u in the Far East.

Immigrations were categorized as mass or minor according to the density of immigrants surveyed by various traps. The mass immigrations were induced by the passage of depressions which emerged in the central part of the Chinese continent between 25 °N and 35 °N and proceeded eastwards between the observation point and about 600 km north. Warm and humid south west winds blew, on average, for 19.3 h at an average wind speed of 32.9 km/h. When the route digressed a little north or south, minor immigrations, with only S.furcifera in half the cases, occurred.

Minor immigration types were categorized into a long‐lasting type which appeared in the final stage of the rainy season, a mass immigration typemodified by the location of a typhoon in the south, and a minor type near the frontal line occurring without the passage of recognizable depressions.

The greatest aerial densities of immigrants were estimated as three to seven per 103m3 in S.furcifera and one to two per 103 m3 in N.Iugens. Female immigrants were mostly unmated.

All the depressions that appeared in June and July 1967–72 were analysed and twenty‐nine (76.3%) out of thirty‐eight originating in the central part of the Chinese continent, caused immigrations. Yearly fluctuations of planthopper infestations in Japan were shown to depend on the yearly fluctuations of the route of depressions associated with the migration of the planthoppers.
Ichneumonoidea (Hymenoptera) parasitic upon leaf‐mining insects of the orders Lepidoptera, Hymenoptera and Coleoptera
Authors: SHAW M. R. , ASKEW R. R.
Published: March 2008

Rearing records of fourteen species of Braconidae and thirteen species of Ichneumonidae from leaf‐mining insects of the orders Lepidoptera, Hymenoptera and Coleoptera are presented.

Braconidae are more abundant and specialized than Ichneumonidae in the parasite faunas of leafminers on both deciduous trees and low‐growing plants.

Although seldom comprising a major element in the parasite complex on deciduous trees, Braconidae are sometimes numerically the dominant parasites on low‐growing plants.

Apanteles circumscriptus associated with Fagaceae is shown to reproduce thelytokously.
The searching behaviour of Anthocoris confusus (Reuter) in relation to prey density and plant surface topography
Authors: EVANS H. F.
Published: March 2008

The searching behaviour of A.confusus females was investigated in an artificial arena.

Females showed an increase in the frequency of turning movements following feeding and this concentrated search in a small area. As a result more prey were found in areas where prey distribution was clumped.

If no prey was encountered within 5–8 min the search track straightened out.

First and second instar nymphs searching on broad bean plants moved faster on the undersides of leaves which were the sites most likely to support aphid populations. A considerable proportion of available time was wasted in periods of inactivity.

It was concluded that while plant topography strongly influences search pattern, the underlying trend demonstrated in these experiments was of advantage to predators searching for colonial prey.
Identification of immature aphids by chromatography
Authors: HENDERSON I. F. , LOXDALE H. D. , GREENWOOD SUSAN P.
Published: March 2008

Immature apterae of five species of cereal aphid were distinguished by ultraviolet examination of chromatograms of their fluorescent pigments.

Non‐expert examiners could identify Metopolophium dirhodum, Sitobion fragariae and Rhopalosiphumpadi with a mean reliability of 98, 83 and 71% respectively; Metopolophium festucae and Sitobion avenae could be separated from the rest but not from each other.

All species gave consistent chromatograms whether reared on oats or on wheat: some species produced atypical traces if reared on certain grasses.
Host‐specificity amongst arthropods ectoparasitic upon mammals and birds in the New Hebrides
Authors: MARSHALL ADRIAN G.
Published: March 2008

Examination of 606 mammals of seventeen species and 959 birds of thirty‐three species yielded sixty‐three species or species groups of ectoparasitic arthropod. These included eighteen species of Acari, twenty‐five species or species groups of Phthiraptera, eighteen species of Diptera Pupipara, and two species of Siphonaptera. These are listed with their hosts and island localities, and host associations noted.

Host specificity amongst ectoparasitic insects is discussed, and the insects classified into four groups of decreasing specificity.

Several broad factors likely to encourage specificity are noted, and it is concluded that the wide diversity of specificity observed is caused by complex interaction of these factors.
The migrations of the hesperid butterfly,Andronymous neanderPlötz, in Africa
Authors: WILLIAMS C. B.
Published: March 2008

The records of migration ofAndronymus neanderin Africa are summarized and mapped.

The present known distribution suggests a possible difference between their behaviour in East and West Africa.

At Amani, in North‐East Tanzania, migrations of millions of individuals were recorded flying SW in March, April and May; their direction of flight was independent of the direction of the wind in nine different years.
Factors determining the distribution of sycamore aphids on sycamore leaves during summer
Authors: DIXON A. F. G.
Published: March 2008

In summer the sycamore aphid's responses to gravity, light direction and intensity and unidentified features of a leaf's surface result in the aphid settling and feeding on the undersurface of leaves.

At this time the petioles are a poor source of food and are not colonized.

Removal of leaf laminae results in premature abscission of the petioles. Prior to abscission the petioles become senescent and a richer food source than the laminae of mature leaves, and are colonized by aphids.
Mutual interference between predatory anthocorids
Authors: EVANS H. F.
Published: March 2008

The way in which the predator Anthocoris confusus reacts to the presence of other individuals of the same species is described.

Mutual interference between adult A.confusus leads to a density‐dependent decrease in egg production, due mainly to an increased tendency to migrate from areas of high predator density.

Even when ten first instar predators were present in a 2 cm diameter cage they did not interfere with each other unless the amount of food available was inadequate for survival.

Mutual interference between A.confusus adults promotes stability in populations of the predator and will lead to even exploitation of an unevenly distributed food source.
Deterrent chemicals as a basis of oligophagy in Locusta migratoria (L.)
Authors: BERNAYS E. A. , CHAPMAN R. F.
Published: March 2008

Abstract. (1) One hundred and two plants were offered to locust nymphs after a 5 h period without food. Large meals were only taken on grasses and on Juncus. Most dicotyledons were totally rejected.

(2) All the plants which were relatively unpalatable yielded an extract which reduced the amount eaten, but no inhibition of feeding was induced by extracts of plants which were freely eaten. Very few of the extracts increased the amount eaten.

(3) Over 100 chemicals, mostly non‐nutritional, known to occur in leaves, were tested for their inhibitory effect on feeding. Some had no effect, but most progressively inhibited feeding as their concentration was increased until no feeding at all occurred. Chemicals of many classes had this effect, but alkaloids and monoterpenoids were the most consistently deterrent at the lowest concentrations.

(4) It is concluded that the failure to eat most plants results from the presence in the leaves of one or more chemicals in amounts which inhibit feeding. Grasses and a few other plants are readily acceptable because they do not contain deterrent chemicals in sufficient quantity to limit feeding.
Swarming behaviour in the Australian beetle, Heteronyx obesus, with notes on related species
Authors: MORGAN F. DAVID
Published: March 2008

Abstract. (1) Heteronyx obesus swarmed about twice annually on evenings when relative humidity was > 80% and temperature was at or above 20°C at 19.30 hours local time.

(2) Swarms were characterized by the frenzied, random flight of their component insects, and the clustering of males about females on vertical structures.

(3) Early the following morning beetles searched for pasture containing favoured food plants, and then burrowed into the soil near them.

(4) Adults did not ingest food before, during or for several days after swarming; the oesophagus and crop of all insects dissected was distended with gas, probably air. This condition appeared to be associated with pre‐flight behaviour of individuals.

(5) The post‐swarm activity was concerned with feeding, dispersal, maturation of eggs and oviposition.

(6) The distribution of individuals of the next generation was strongly influenced by presence in the sward of favoured food (sorrel, Rumex species) of the adults.
Dispersion and the size composition of the aerial insect fauna
Authors: HESPENHEIDE HENRY A.
Published: March 2008

Abstract. 1. Beetles sampled in Louisiana at higher levels in the atmosphere were significantly smaller than those sampled at lower levels, which suggests that passive buoyancy is important in high altitude dispersal.

2. A model of long‐range dispersal is suggested which combines both active flight and passive buoyancy.
Food conversion efficiency of a parasitic wasp, Nemeritis canescens
Authors: HOWELL J. , FISHER R. C.
Published: March 2008

Abstract. 1. The calorific efficiency with which N. canescens converts the larva of E. kuehniella into its own tissues has been measured by microbomb calorimetry.

2. The calorific values found for Ephestia larvae are high in comparison with those of other insects and may be associated with their high fat content.

3. The growth efficiency of 61% achieved by Nemeritis is sustained by the higher assimilation efficiency of 94%, owing to the parasitoid's habit of feeding directly on the host's haemolymph.

4. The overall efficiency of conversion of adult moth (host) to adult ichneumonid (parasitoid) is of the order of 59% which is broadly representative of endoparasitoids and higher than that achieved by true predators.
Analysis of solitariness in a parasite—host system (Muscidifurax raptor, Hymenoptera: Pteromalidae—Ceratitis capitata, Diptera: Tephritidae)*
Authors: PODOLER H. , MENDEL Z.
Published: March 2008

Abstract. 1. The behaviour of the parasite Muscidifurax raptor Girault and Sanders was studied when searching for hosts, puparia of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). At low density females tend to avoid encountering parasitized hosts. This tendency decreases as density of searching females increases.

2. The proportional avoidance of superparasitism was calculated and the effect of increasing number of encounters per host on this parameter was analysed.

3. The mechanisms of solitariness were studied. These mechanisms include: outer marking of the hosts by the female parasite and deliberate physical attack of the newly hatched larvae to eliminate as yet unhatched eggs.

4. In cases of intraspecific competition between larvae, young first or second instar larvae usually have the advantage over older larvae.
The role of substrate preparation in the symbiosis between the leaf‐cutting ant Acromyrmex octospinosus (Reich) and its food fungus
Authors: QUINLAN R. J. , CHERRETT J. M.
Published: March 2008

Abstract. 1. In laboratory nests the ants thoroughly licked leaf fragments by a rasping action of their glossa before inoculating the food fungus. The extent of this licking varied with the substrate and was influenced by the thickness of surface leaf waxes and by the chemical attractiveness of the substrate.

2. Microscopy and wettability studies showed that licking removes the wax layer present on leaves. It also removes or inhibits micro‐organisms present.

3. Chemically de‐waxed and decontaminated leaves and ant‐licked leaves proved the best substrates for artificially culturing the ant fungus.

4. The process of substrate preparation circumvents some of the normal defence mechanisms of green plants against fungal attack. The ant fungus thus utilizes nutritionally richer resources of green leaves normally available only to specialized parasitic fungi, rather than the nutritionally inferior shed leaves normally available to saprophytic fungi.
Problems of orientation associated with cocoon‐spinning by Nemeritis
Authors: SALT GEORGE
Published: March 2008

Abstract. 1. Larvae of Nemeritis that have reached full growth in a caterpillar of Ephestia invariably push the host remains towards the closed end of the host cocoon and pupate with their heads towards the open end. Larvae reaching full growth in a pupal host are usually orientated in the same direction, but occasionally in reverse.

2. The parasitoid does not orientate itself by direct reference to the host cocoon but in relation to the final position of the host. The host remains are probably used as a point of reference.

3. As the parasitoid spins its own cocoon, it isolates itself from some external stimuli and has need of a new point of reference. It provides this by incorporating guide marks, in the form of areas of specially woven threads, in successive layers of its cocoon.

4. The final mark, on the innermost layer, not only indicates the anterior end of the cocoon, but also may help the adult to bite its way out.

5. The presence of similar marks has been observed in the cocoons of five other species of Ichneumonidae, representing the two subfamilies Ophioninae and Cryptinae.

6. The significance of these provisions for correct orientation of ichneumon wasps is briefly discussed.
Sampling techniques and preparation of partial life tables for the olive fly, Dacus oleae (Diptera: Trypetidae) in Corfu
Authors: KAPATOS E. , McFADDEN M. W. , PAPPAS S.
Published: March 2008

Abstract. 1. A sampling plan was developed for the immature stages of D.oleae (Gmel.) by analysing data from samples of infested fruits taken during the years 1973, 1974 and 1975.

2. The number of samples required to attain a certain precision is largely a function of density, so that the level of sampling can be determined approximately for a given density of immature stages.

3. Partial life tables were constructed for the main developmental periods of the successive generations of D.oleae. For most of the year the number of eggs laid, rather than mortality, determined the size of the resulting population of pupae.

4. In September mortality of the third larval instar is high, mainly due to parasitism and this decreases considerably the number of pupae produced during this period.
Observations on the biology and ecology of the chrysomelid genus Haltica Geoff, in Britain
Authors: PHILLIPS W. M.
Published: March 2008

Abstract. 1. Ecological observations were made on four species of the genus Haltica and the life cycle described, with particular reference to H.lythri Aubé.

2. The species are usually univoltine although a second egg laying period may occur.

3. Post hibernation aggregation behaviour of adulls occurs in the spring and feeding damage is often localized. First instar larvae of H.lythri feed in groups.

4. Parasitism by Perilitus sp. (Hymenoptera, Braconidae), Degeeria luctuosa Meigen (Diptera, Tachinidae), gregarine protozoa, Nematoda (Mermithidae) and a fungus, Verticillium sp., is reported.

5. Hemiptera are important predators of some Haltica species. Eggs of H.lythri were attacked by the mirid Dicyphus epilobii Reuter. Larvae of H.oleracea and H.lythri were preyed upon by the pentatomid Zicrona coerula (L.).

6. Feeding tests with carabid beetles suggested that Stomis pumpicatus (Pz) may be a potential predator of larvae of H.lythri.

7. Chemical secretions at the tips of spined tubercles of first instar larvae may have a defensive function. Other defence mechanisms are described.
The oviposition biology of siricid woodwasps in Europe
Authors: SPRADBERY J. P.
Published: March 2008

Abstract. 1. The oviposition biology of the siricid woodwasps, Sirex noctilio, S.juvencus, S.cyaneus, Urocerus gigas, U.augur, U.fantoma, U.sah and Xeris spectrum was investigated. The fecundity of each siricid species was related to adult size although S.noctilio laid relatively fewer eggs than other species.

2. Oviposition drill architecture in host trees is characteristic for the different siricid genera and was found to be related to the length of the ovipositor. The shape of the egg is also characteristic for each genus.

3. Species of the symbiotic fungus, Amylostereum, were found to be associated with all species except X. spectrum. The emplacement of fungus in relation to oviposition drills was investigated.

4. S.noctilio females have relatively larger mucus glands and reservoirs than other siricid species.

5. The response of X.spectrum females to previously infested timber was studied experimentally. A positive response to previously infested timber and Amylostereum inoculated sawdust was demonstrated.

6. The longevity of adults, oviposition rates and incubation period of eggs was investigated.

7. The results are discussed in relation to the ecology of siricids in Europe and Australia.
Comparative flight performance of the seasonal morphs of the cabbage whitefly, Aleyrodes brassicae (Wlk.), in the laboratory
Authors: IHEAGWAM EMMANUEL UCHE
Published: March 2008

Abstract. 1. The flight capacity of the summer (non‐diapausing) and the winter (diapausing) females of A.brassicae was assessed in terms of the climbing flight directed phototactically toward an overhead source of light in a laboratory flight chamber.

2. The summer morph took off only when prodded and its flight bouts were much briefer than those of the winter morph.

3. Immediately on take‐off, the summer morph sank in flight and was negatively phototactic in the horizontal plane whereas the winter morph climbed on take‐off, being positively phototactic both vertically and horizontally.

4. Three phases of behaviour during flight were observed in the winter morph: a short period of widely fluctuating rate of climb, a long ‘cruising’ phase of steady climbing, and a final erratic phase when the rate of climb had fallen to and below zero.

5. In general, the mean rate of climb was significantly higher on re‐take‐off after a landing than immediately before the landing.
The distribution pattern of herbivory in a beech canopy
Authors: NIELSEN B. OVERGAARD , EJLERSEN A.
Published: March 2008

Abstract. (1) The spatial distribution pattern of herbivory by phyllophagous canopy arthropods in a 90‐year‐old beech stand was analysed.

(2) Two main patterns of spatial distribution were recorded. The leaf mining moths Phyllonorycter maestingella and Stigmella hemargyrella and the adult weevils Rhynchaenus fagi and Phyllobius argentatus mainly attacked the under‐story and the latter species especially the low canopy in the central part of the stand. Mines of R. fagi chiefly occurred in the top of the overstory canopy or at the fringe of the stand. However, comparable distribution patterns are only expected in mature beech stands composed of distinct overstory and understory layers.

(3) The effect of the actual spatial distribution pattern of herbivory on photosynthesis, productivity, and transpiration of beech in the research stand is discussed. It is suggested that in some cases the shade leaves of the understory canopy may cushion the effect of herbivory in the beech stand.
Sinking speeds of falling and flying Aphis fabae Scopoli
Authors: THOMAS A. A. G. , LUDLOW A. R. , KENNEDY J. S.
Published: March 2008

Abstract. 1. The terminal velocities of freshly anaesthetized and weighed, virginoparous alatae were measured by dropping them into updrafts of known speed. For an average specimen weighing about 0.49 mg the terminal velocity was 1.78 ms‐1 with wings closed and 0.82 ms‐1 with wings fully extended horizontally.

2. Extrapolating from the known terminal velocities of falling spheres of appropriate density, it is concluded that for inertly falling insects of constant shape the terminal velocity will be substantially lower with the wings extended than with them closed for all sizes of insect and that the horizontal distance travelled during a fall will be correspondingly greater.

3. Sudden reflex immobilization and falling was sometimes observed in aphids flying in a laboratory flight chamber, and very occasionally this immobilized state was maintained for many seconds (even during handling) before recovery and renewed flight. There was no evidence of a special falling attitude (‘Fall‐reflexhaltung’) other than a simple ‘frozen flight’ attitude with wings extended horizontally and legs extended fore and aft while the insect spiralled downwards, abdomen first.

4. The flying aphid's usual response to a coloured surface below it in the flight chamber was not to cease wing‐beating and fall but to fly downwards, abdomen first, at speeds up to more than 0.7 m s‐1.
Pheromone response and sexual behviour of Cephalcia lariciphila Wachtl (Hymenoptera: Pamphiliidae)
Authors: BORDEN J. H. , BILLANY D. J. , BRADSHAW J. W. S. , EDWARDS M. , BAKER R. , EVANS D. A.
Published: March 2008

Abstract. 1. Trapping experiments and observations of sexual behaviour were made on Cephalcia lariciphila in infested larch forests in Hereford and Worcester and Mid‐Glamorgan in early May 1977.

2. The results indicated that virgin females and dichloromethane extract of crushed virgin females were highly attractive to males.

3. On 17 May males responded to females throughout the warmest part of the day. First response occurred before 09.00 hours, the last after 17.00 hours and peak activity was from 11.00 to 14.00 hours.

4. Mated females became unattractive to males within 10 min after mating. When mated females or males were paired with virgin females there was no evidence of an anti‐attractive pheromone or pheromone mask.

5. A few males dispersed out of larch into adjacent spruce forests and were captured in virgin female‐baited traps up to 135 m distant from infested larch. Virgin female‐baited traps at 0–0.5 m from the ground captured over seven times the number of males as traps at 1, 2 or 4 m, supporting visual observations that the preferred flight level for males is very near the ground.

6. Horizontal board traps with an acetate surface coated with ‘Stikem Special’ were superior to Pherocon IC, vertical board and gypsy moth traps in that order.

7. The observations and results suggest that the best applied uses of C. lariciphila pheromone would be in survey and detection, and male disruption techniques.
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.glauca

3. 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.