bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aspiration cytology of Hashimoto's thyroiditis in an endemic area
Authors: KUMAR NEETA , RAY CHETAN , JAIN SHYAMA 
Published: March 2003

Aspiration cytology of Hashimote's thyroiditis in an endemic area Fine needle aspiration (FNA) plays a significant role in the diagnosis of thyroid lesions due to its simplicity and low cost. Hashimoto's thyroiditis (HT) is the second most common thyroid lesion next to endemic goitre diagnosed on FNA in iodine (I2) deficient areas. Data on its incidence, prevalence and clinicopathological features in I2 deficient areas is scanty compared to I2 sufficient areas. In the present study the patients presented with HT a decade earlier than reported in I2 sufficient areas. Presentation as a nodular thyroid is common. Diagnosis of HT is likely to be missed in smears showing cytological evidence of hyperplasia or abundant colloid. HT was concurrent in 20 cases of endemic goitre. Careful screening for Hurthle cell change and lymphocytic infiltration into follicular cells should be carried out. In equivocal cases multiple punctures and immunological investigations are helpful. In antibody‐negative cases repeat FNA at follow‐up is useful. Marked lymphocytic infiltration and Hurthle cell change may indicate a hypothyroid state but hormonal levels are required for clinical management.
Timing of diapause initiation, metabolic changes and overwintering survival of the spruce budworm, Choristoneura fumiferana
Authors: HAN ER‐NING , BAUCE ERIC 
Published: March 2003

1. Four groups of spruce budworm larvae, Choristoneura fumiferana, of the same physiological stage (at the beginning of diapause) were exposed to natural temperatures, starting in July, August, September and October. Post‐diapause emergence and certain metabolites were monitored throughout the overwintering period.2. Larval exposure to high temperatures for long periods before winter had a significant effect on temperature requirements for subsequent diapause development and apparently caused a certain amount of mortality, especially for those larvae that entered diapause earlier in the season.3. Substantial loss of lipid and glycogen reserves was related to intensity of high temperature exposure during the pre‐winter period, which in turn was associated with the timing of diapause initiation.4. Patterns of glycerol accumulation during the winter were also influenced by temperature conditions in the early phase of diapause development.5. Among several possible mortality factors, an extended cool period in spring was suggested as a potential cause of overwintering mortality, which was closely associated with a deficiency in energy reserves caused by high temperature exposure before winter.6. These results stress the significant impact of pre‐winter conditions on the overwintering process and highlight the importance of an ecophysiological approach to insect overwintering biology.
Interactive effects of herbivory and sand burial on growth of a tropical dune plant, Ipomoea pes‐caprae
Authors: BACH CATHERINE 
Published: March 2003

1. This study examined the effects of insect herbivory, sand burial, and the interactive effects of these factors, on the growth of beach morning glory, Ipomoea pes‐caprae, a common tropical dune plant. Levels of herbivory and sand burial were manipulated on individual shoots, and effects on stem growth, leaf production, and production of adventitious roots and axillary branches by nodes were examined.2. Sand burial had a significant positive effect on the production of roots, but did not affect growth in stem length or leaf production.3. Effects of herbivory were consistently negative, and persisted for 6 weeks after the herbivore damage was incurred. Stem growth rates and leaf production decreased and the production of bare nodes (with no roots or branches) and mortality of apical meristems increased.4. Interactive effects of herbivory and sand burial influenced both leaf production and root production. In the case of root production, the effects of herbivory in decreasing the proportion of nodes that produced roots occurred only in the presence of burial. In contrast, burial masked the negative effects of herbivory on leaf production.
Trade‐off between diapause and other life‐history traits in the spider mite Tetranychus urticae
Authors: KROON ANNEMARIE , VEENENDAAL RENÉ 
Published: March 2003

1. Diapause is generally believed to entail costs that manifest themselves as decreased survival, rate of development, and/or reproduction after diapause completion. The present study is a first step in investigating such diapause costs in the spider mite Tetranychus urticae.2. The relationship was assessed between diapause duration and the post‐diapause life‐history traits of longevity and egg production, under six photoperiods at 19 °C.3. The relationship between diapause duration and longevity was negative under five out of six treatments; in three cases this negative relationship was significant.4. Most evident were the negative correlations between diapause duration and rate of oviposition, peak rate of oviposition, and total egg production. These phenotypic correlations suggest that there may be a trade‐off between diapause duration and post‐diapause reproduction.
Learning in the nectar foraging behaviour of Helicoverpa armigera
Authors: Cunningham J. P. , West S. A. , Wright D. J. 
Published: March 2003

Abstract.1. Learning may enable insects to obtain nectar from flowers more efficiently. Learning in nectar foraging has been shown primarily in studies of bees and butterflies. Here, learning is demonstrated in the nectar foraging behaviour of a noctuid moth, Helicoverpa armigera.2. The present studies show that: (1) previous experience with a flowering host species increases the probability of that species being selected for nectar foraging, and (2) previous experience of a particular flower type (food source at bottom or top of the corolla tube) increases the likelihood of the food source being found when that flower type is being searched.3. The implications of these findings for understanding the pattern of oviposition observed in wild populations of this important pest species are discussed.
Behaviour of a specialist parasitoid, Cotesia melitaearum: from individual behaviour to metapopulation processes
Authors: Lei Guang‐ChuN. , Camara MarK. D. 
Published: March 2003

Abstract. 1. Foraging behaviour and movement within and among host patches of the specialist parasitoid wasp Cotesia melitaearum (Braconidae) attacking the larvae of Melitaea cinxia (Nymphalidae) were studied in the field and in the laboratory.2. In the field, female wasps aggregated in large host groups in the autumn and caused positive spatial density‐dependent parasitism in the field. Wasps stayed longer with groups of pre‐diapause caterpillars than with post‐diapause caterpillars, but attacked them less frequently.3. In the laboratory, wasps attacked larger larvae more readily than smaller larvae. Also in the laboratory, wasps exposed to larvae outside their protective webs showed differences in the rates at which they attacked larvae fed different diets, implicating host plant‐derived chemicals as proximate cues for foraging wasps.4. Mark–recapture studies indicated that there was a low rate of successful movement of wasps among groups of young larvae within a habitat patch in the autumn and no successful movement of wasps across non‐habitat. In contrast, wasps moved frequently among groups of late‐instar caterpillars in the spring.5. Host caterpillars of different ages responded very differently to wasp attacks. Pre‐diapause larvae remained in groups and used collective head‐jerking behaviour to defend themselves, whereas post‐diapause larvae dispersed away from the group immediately after being attacked.6. Population and metapopulation level dynamics of the host–parasitoid interaction are discussed in light of these observations of the behaviour of individual wasps.
Cross‐correlation analysis of fluctuations in local populations of pear psyllids and anthocorid bugs
Authors: Scutareanu Petru , Lingeman RoB. , Drukker BaS. , Sabelis Maurice W. 
Published: March 2003

Summary1. To test whether predatory anthocorids migrate into pear orchards when populations of pear psyllids are building up, a cross‐correlation analysis was carried out on their population numbers. Predator and prey population sizes were assessed weekly in 3 consecutive years (1991–93) by sampling pear leaves for eggs and nymphs of psyllids and pear tree branches for adult psyllids, as well as adults and nymphs of predatory anthocorids. The time‐series consisted of numbers (per leaf or branch) averaged over preselected pear trees in an orchard and, in addition, over other trees selected along the hedgerows flanking the orchard.2. The fluctuations in populations of adult and juvenile anthocorids showed strong cross‐correlations with those of the eggs and nymphs of pear psyllids, but less correlation with adults of pear psyllids, as expected based on their increased ability to escape from predation. The psyllids always appeared first on the pear trees, resulting in positive phase shifts. The first peak of adult anthocorids on pear trees was always later than the first peak in the hedgerows, and the first peak of nymphal anthocorids on pear trees was always later than the first peak of adults on these pear trees. In each of the 3 years, anthocorids were rarely observed in the pear orchard during the first part of the growing season (April–June), but during the second half of the growing season (July–August) there was a strong numerical response of the anthocorid populations to increasing population densities of pear psyllids.3. These results provide support for the hypothesis that the numerical response of the predators to prey density is caused initially by migration of anthocorids into the pear orchard and then by a reproductive response. The migrants originate from the hedgerows and other trees elsewhere, where they feed on aphids during the first part of the growing season.
Conditional expression of a sexually selected trait in the stalk‐eyed fly Diasemopsis aethiopica
Authors: Knell R. J. , Fruhauf N. , Norris K. A. 
Published: March 2003

Summary1. An important assumption of many models of the evolution of sexually selected ornaments is that such ornaments should be conditionally expressed. This was investigated by rearing larvae of the stalk‐eyed fly Diasemopsis aethiopica (Diptera: Diopsidae) (Rondani) on two food treatments: normal and low‐quality food.2. Female flies responded to better food by increasing both their body size and the relative length of their eyestalks.3. Male flies responded by increasing only the length of their eyestalks.4. This demonstrates that food quality can change the allometric relationship between body size and the size of a sexually selected character in this species, and gives an insight into the different developmental priorities of each sex in this species.
The role of behavioural ecology of damselflies in the use of fluctuating asymmetry as a bioindicator of water pollution
Authors: Hardersen Sönke 
Published: March 2003

Summary1. Fluctuating asymmetry has been used widely to investigate questions concerned with evolution and behaviour, and to study the effects of environmental pollution. Damselflies have been used to answer questions in both fields, but no attempt has been made to combine the knowledge from these areas to investigate whether and how evolutionary ecology and behaviour interfere with the use of fluctuating asymmetry as a bioindicator of water pollution.2. Four hypotheses were formulated to investigate possible interferences: (1) Paired males should be less asymmetrical than unpaired males. (2) Males caught at breeding sites should be less asymmetrical than females caught at breeding sites. (3) Damselflies caught earlier in the season should be less asymmetrical than those caught later in the year. (4) Damselflies caught at control sites should be less asymmetrical than those caught at sites within areas of high pesticide usage.3. No significant difference in asymmetry levels was found between paired and unpaired males.4. Males were significantly less asymmetrical than females.5. Damselflies caught earlier in the year were less asymmetrical than those caught later.6. The data used to test the hypothesis that fluctuating asymmetry in the wings of mature damselflies reflects the level of pesticides used in the surrounding environment were equivocal.7. The findings suggest that evolutionary ecology and behaviour interfere with the suitability of fluctuating asymmetry in mature damselflies as a biomonitoring tool and it is concluded that fluctuating asymmetry in emerging adults should be much more appropriate as a bioindicator.
Flower‐feeding affects mating performance in male oriental fruit flies Bactrocera dorsalis
Authors: Shelly Todd E. 
Published: March 2003

Summary1. Males of the oriental fruit fly Bactrocera dorsalis are attracted to and feed on flowers of the golden shower blossom Cassia fistula. Flowers of this plant contain methyl eugenol, the metabolites of which apparently function in the synthesis of male sex pheromone.2. The goal of the study reported here was to determine whether feeding on C. fistula flowers enhanced male mating success. Mating frequencies of unfed (control) and fed (treated) males were compared in trials conducted 0 (same day), 2, 7, or 21 days after treated males were exposed to the flowers. Trials were performed using flowers from three trees of C. fistula to investigate whether the effects of floral feeding were similar among different plants.3. For all three trees, treated males accounted for a disproportionately large number of matings in trials performed 0, 2, and 7 days after floral feeding by the treated males. For two of the trees, treated males also had a mating advantage 21 days after flower‐feeding.4. Additional tests were conducted to compare female attraction to perch sites of control and treated males. When at a lek, males exhibit rigorous wing‐fanning behaviour, presumably to increase dispersal of the sex pheromone. Floral feeding had no significant effect on the level of wing‐fanning. Significantly more female sightings were recorded for perches of treated than control males, however, suggesting that the treated males produced a pheromone more attractive to females than did control males.
Does the diapause experience of bumblebee queens Bombus terrestris affect colony characteristics?
Authors: Beekman M. , Van Stratum P. 
Published: March 2003

Summary1. Bumblebee colonies show much variation in the number of workers, drones, and queens produced. Because this variation prevails even when colonies are kept under identical conditions, it does not seem to be caused by extrinsic factors but rather by differences between founding queens.2. The most likely factor that could cause differences between queens is diapause. Although colonies are raised under standardised conditions, the queens often experience diapause of different length. If there are costs associated with diapause that influence post‐diapause reproduction, the diapause history of the queens could affect colony characteristics.3. Here, several colony characteristics are compared: number of first and second brood workers; total number of workers, drones, and queens; energy spent on sexuals; sex ratio; rate of worker production; time to emergence of first reproductive; and colony lifetime. Colonies were used where the queens experienced a diapause treatment of 0 (nondiapause queens), 2, and 4 months.4. Although no proof was found for the existence of costs associated with diapause, the colony characteristics of nondiapause queens were significantly different from those of diapause queens. Colonies of nondiapause queens produced the lowest number of workers but the highest number of young queens.5. It is argued that these nondiapause colonies are more time‐constrained than diapause colonies because nondiapause colonies produce two generations within the same season and should therefore be more efficient in producing sexual offspring.6. Moreover, nondiapause colonies should rear a more female‐biased sex ratio because they can be certain of the presence of males produced by other (diapause) colonies.
The effect of sperm storage and timing of mating on offspring sex ratios in the yellow dung fly Scatophaga stercoraria
Authors: Seal Nicola J. 
Published: March 2003

Summary1. Offspring sex ratios in the yellow dung fly Scatophaga stercoraria were examined in the laboratory.2. Previous work indicated that females using previously stored sperm to fertilise their eggs produced male‐biased sex ratios. This result may have been due to female influences or the effects of sperm storage per se.3. This pattern was not reproduced in the study presented here. Females that were allowed to mate just prior to oviposition produced similarly male‐biased sex ratios to those females that used previously stored sperm to fertilise their clutch.4. Captive‐reared females may have perceived a lack of males in the population and thus produced a male‐biased offspring sex ratio. Alternatively, gamete ageing or extra‐chromosomal sex ratio distorters may have produced the male bias.
Dynamic effects of parasitism by an endoparasitoid wasp on the development of two host species: implications for host quality and parasitoid fitness
Authors: Harvey Jeffrey A. 
Published: March 2003

Summary1. The study reported here examined growth and developmental interactions between the gregarious larval koinobiont endoparasitoid Cotesia glomerata (Hymenoptera: Braconidae) and two of its hosts that vary considerably in growth potential: Pieris rapae and the larger P. brassicae (Lepidoptera: Pieridae). At pupation, healthy larvae of P. brassicae are over twice as large, in terms of fresh body mass, as those of P. rapae.2. Clutch size of C. glomerata was manipulated artificially, and the relationship between parasitoid burden and the maximum weight of the parasitised host (= host–parasitoid complex) was measured. In both hosts, the maximum complex weight was correlated positively with parasitoid burden. Compared with unparasitised hosts, however, the growth of P. rapae was increased at significantly lower parasitoid burdens than in P. brassicae. Emerging wasp size was correlated negatively with parasitoid burden in both host species, whereas development time was less affected.3. After larval parasitoid egress, the weight of the host carcass increased slightly, but not significantly, with parasitoid burden, although there was a strong correlation between the proportion of host mass consumed by C. glomerata larvae during development and parasitoid burden.4. Clutch size was generally correlated positively with instar parasitised in both hosts, and greater in P. brassicae than in P. rapae. Sex ratios were much more female biased in L1 and L2 P. rapae than in all other host classes. Adult parasitoid size was correlated inversely with host instar at parasitism, and wasps emerging from P. brassicae were larger, and completed development faster, than conspecifics emerging from P. rapae.5. The data reveal that parasitism by C. glomerata has profound species‐specific effects on the growth of both host species. Consequently, optimality models in which host quality is often based on host size at parasitism or unparasitised growth potential may have little utility in describing the development of gregarious koinobiont endoparasitoids. The results of this investigation are discussed in relation to the potential effectiveness of gregarious koinobionts in biological control programmes.
Habitat selection in a large orb‐weaving spider: vegetational complexity determines site selection and distribution
Authors: Mcnett Bonnie Jean , Rypstra Ann Lundie 
Published: March 2003

Summary1. The distribution of the large orb‐weaving spider Argiope trifasciata in old field habitats of North America and the habitat selection process this species used was studied for 2 years.2. Because web spiders have limited dispersal abilities and an energetically costly prey capture device, they do not have the ability to sample potential foraging sites. Structural complexity of the vegetation to which the web must be attached is relatively easy to assess. The hypothesis that the structural complexity is a primary factor in determining initial web site selection was tested both by relating the natural distribution of the spiders across habitats to vegetational complexity and by manipulating the complexity of the habitats in a series of experiments.3. Argiope trifasciata was not distributed evenly among three old field vegetation types. Habitat complexity was related to spider density in both years although no measure of insect activity, prey capture, or prey consumption was correlated with spider distribution.4. Three experimental manipulations were conducted to test the impact of habitat structure on spider establishment: (1) the amount of natural vegetation was reduced, (2) structures were added to a simple habitat, and (3) the complexity of the structures added was varied. In each case, spiders were introduced and establishment of webs was monitored. In all manipulations, spider establishment was related to the complexity of the substrate available.5. These results are important for understanding the cues that influence foraging site selection and therefore provide insight into the distribution of species with limited dispersal abilities and high site investment requirements.
Nutritional benefits of intraguild predation and cannibalism among generalist and specialist phytoseiid mites
Authors: Schausberger Peter , Croft Brian A. 
Published: March 2003

Summary1. Intraguild predation and cannibalism are common among predaceous phytoseiid mites (Acari, Phytoseiidae) but the nutritional benefits gained by these processes are poorly understood.2. The study reported here addressed the questions of whether cannibalism and intraguild predation provide different nutritional benefits and whether the ability to utilise cannibalism and intraguild predation is linked to the diet specialisation of phytoseiid mites. Specialists tested werePhytoseiulus macropilis,Galendromus occidentalis, andNeoseiulus longispinosus;generalists tested wereAmblyseius andersoni,Neoseiulus cucumeris, andNeoseiulus fallacis.3. All generalists and the specialistP. macropiliswere able to complete juvenile development with both con‐ and hetero‐specific prey. Juvenile development of generalists was shorter with heterospecific prey than with conspecific prey, whereas development of the specialistP. macropilisdid not differ between prey types. Only a fewN. longispinosusandG. occidentalis, both specialists, reached adulthood by cannibalism but none reached adulthood by intraguild predation.4. All generalists were able to sustain oviposition by intraguild predation.Neoseiulus cucumerisandA. andersonilaid more eggs with heterospecific prey than with conspecific prey, whereasN. fallacishad similar oviposition rates with both prey types. No specialist sustained oviposition by intraguild predation or cannibalism.5. Overall, generalists gained equal or more nutritional benefits by intraguild predation than by cannibalism and were able to utilise phytoseiid intraguild prey as an alternative food source. Specialists gained equal or more nutritional benefits from cannibalism than from intraguild predation. For specialists, con‐ and hetero‐specific phytoseiids may be considered only a supplemental food.