bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of caffeine and high ambient temperature on haemodynamic and body temperature responses to dynamic exercise
Authors: Stebbins Charles L. , Daniels Jason W. , Lewis William
Published: March 2003

Caffeine can enhance mean arterial blood pressure (MAP) and attenuate forearm blood flow (FBF) and forearm vascular conductance (FVC) during exercise in thermal neutral conditions without altering body temperature. During exercise at higher ambient temperatures, where a greater transfer of heat from the body core to skin would be expected, caffeine‐induced attenuation of FBF (i.e. cutaneous blood flow) could attenuate heat dissipation and increase body temperature (Tre). We hypothesized that during exercise at an ambient temperature of 38°C, caffeine increases MAP, and attenuates FBF and FVC such that Tre is increased. Eleven caffeine‐naive, active men, were studied at rest and during exercise after ingestion of a placebo or 6 mg kg–1 of caffeine. MAP, heart rate (HR), FBF, FVC, Tre skin temperature (Tsk) and venous lactate concentrations (lactate) were assessed sequentially during rest at room temperature, after 45 min of exposure to an ambient temperature of 38°C, and during 35 min of submaximal cycling. Heat exposure caused increases in MAP, FBF, FVC and Tsk that were not altered by caffeine. HR, Tre, and lactate were unaffected. During exercise, only MAP (95 ± 2 vs. 102 ± 2 mmHg), HR (155 ± 10 vs. 165 ± 10 beats min–1), and lactate (2·0 ± 0·4 vs. 2·3 ± 0·4 mmol l–1) were increased by caffeine. These data indicate that increases in cutaneous blood flow during exercise in the heat are not reduced by caffeine. This may be because of activation of thermal reflexes that cause cutaneous vasodilation capable of offsetting caffeine‐induced reductions in blood flow. Caffeine‐induced increases in lactate, MAP and HR during exercise suggest that this drug and high ambient temperatures increase production of muscle metabolites that cause reflex cardiovascular responses.
Effects of dexamethasone on the metabolic responses to mental stress in humans
Authors: Seematter G. , Battilana P. , Tappy L.
Published: March 2003

The haemodynamic effects of the sympathetic nervous system (SNS) activations elicited by hypoglycaemia, acute alcohol administration, or insulin can be prevented by a pretreatment with dexamethasone in humans. This suggests a possible role of central corticotropin releasing hormone (CRH) release. Mental stress activates the SNS, and decreases systemic vascular resistances through a β‐adrenergic‐mediated vasodilation thought to involve vascular nitric oxide release. It also increases insulin‐mediated glucose disposal, an effect presumably related to vasodilation. In order to evaluate whether activation of SNS by mental stress is glucocorticoid‐sensitive, we monitored the haemodynamic and metabolic effects of mental stress during hyperinsulinaemia in healthy humans with and without a 2‐day treatment with 8 mg day–1 dexamethasone. Mental stress decreased systemic vascular resistances by 21·9% and increased insulin‐mediated glucose disposal by 28·4% without dexamethasone pretreatment. After 2 days of dexamethasone treatment, whole body insulin‐mediated glucose disposal was decreased by 40·8%. The haemodynamic effects of mental stress were however, not affected. Mental stress acutely increased insulin‐mediated glucose disposal by 28·0%. This indicates that mental stress elicits a stimulation of SNS through dexamethasone‐insensitive pathway, distinct of those activated by insulin, alcohol, or hyperglycaemia.
An unusual presentation of fine needle aspiration (FNA) cytology from the syncytial variant of nodular sclerosing Hodgkin's disease
Authors: Stephen M. R. , Mallon E. A.
Published: March 2003

Introduction

Open access breast clinics are now widely available and immediate reporting of FNAs of the breast has become an established part of the triple approach to the management of breast disease1.

We report the unexpected findings of a case of Hodgkin's disease at such a clinic. The patient was a young woman who initially was thought by both her general practitioner and surgeon to have a fibroadenoma in the axillary tail region of her right breast. The FNA of this lump showed the features of Hodgkin's disease but with widespread necrosis, which was unusual and potentially misleading and which we wish to highlight. A lymph node biopsy confirmed the diagnosis and showed that the patient was suffering from the syncytial variant of nodular sclerosing Hodgkin's disease (NSHD).

This variant probably accounts for about 5% of cases of Hodgkin's disease2. Necrosis is a common feature of NSHD; it can range from minute scattered foci to more extensive necrosis of nodules or even involve the entire lymph node.
Aspergillus in the Papanicolaou stain: morphology, fluorescence and diagnostic feasibility
Authors: HETTLICH  , KÜPPER  , WEHLE  , PFITZER
Published: March 2003

hettlich c., küpper th., wehle k. and pfitzer p. (1998) Cytopathology9, 381–388

Aspergillus in the Papanicolaou stain: morphology, fluorescence and diagnostic feasibility

Aspergillus species exhibit a distinct and clear fluorescence in Papanicolaou‐stained cytological samples. The Papanicolaou (PAP) stain enhances the autofluorescence of cultured aspergilli and allows better cytological recognition of the fungus by fluorescence microscopy when it is not easily discerned from its surroundings by light microscopy. Morphological properties can be better distinguished and facilitate the differentiation of aspergillus organisms from other filamentous fungi. Neither light nor fluorescence microscopy, the cytological quality nor the presence of phagocytosed hyphae in alveolar macrophages allow distinction between infection and contamination with Aspergillus species. Only the presence of eosinophilic inflammation permits a tentative diagnosis of an Aspergillus infection. In conclusion, PAP fluorescence reduces the need for special stains, is superior to and quicker than other investigative techniques and enhances the sensitivity and specificity of cytological investigation when a rapid and reliable identification of Aspergillus is needed.
Argyrophilic nucleolar organizer region (AgNOR) technique: a helpful tool for differential diagnosis in urinary cytology
Authors: CIA E. M. M. , TREVISAN M. , METZE K.
Published: March 2003

Argyrophilic nucleolar organizer region (AgNOR) technique: a helpful tool for differential diagnosis in urinary cytology

The aim of this study was to investigate whether the AgNOR technique could be helpful for the cytologic diagnosis of neoplastic and non‐neoplastic urinary tract lesions. We analysed the AgNOR pattern in urinary cytology in samples from 70 patients. In every case the average number of silver precipitations per nucleus was counted and the range between the minimum and maximum AgNOR value calculated. Furthermore we noted whether the AgNOR precipitations had a homogeneous or heterogeneous distribution. The diseases were classified in three groups: non‐neoplastic lesions, low grade and high grade carcinoma. Linear discriminant analysis (with jack‐knife procedure) was performed with the AgNOR parameters as independent variables. The final diagnosis of each patient had been established by histological analysis of bladder biopsies. We obtained a correct classification in 84.3% of the cases. All patients with normal or reactive lesions were correctly classified and only two cases of low grade malignancy were erroneously diagnosed as non‐malignant. Five high grade neoplasms had been classified as low grade and four low grade carcinomas had been over‐diagnosed as high grade neoplasms. We conclude that a combined qualitative and quantitative AgNOR analysis can be useful in the differential diagnosis of urinary cytology.
Single‐strand conformational polymorphism (SSCP)‐detected p53 gene mutations are a less sensitive marker of malignancy in pleural fluids than p53 immunostaining
Authors: Mayall F. , Cursons R. , Jacobson G. , Chang B.
Published: March 2003

Single‐strand conformational polymorphism (SSCP)‐detected p53 gene mutations are a less sensitive marker of malignancy in pleural fluids than p53 immunostaining

p53 immunostaining has been advocated as a marker of malignancy in pleural biopsies and serous fluids. The object of this study was to compare the sensitivity and specificity of p53 immunostaining for the detection of malignant cells in pleural fluids with a technique designed to detect p53 gene mutations in exons 5, 6, 7 and 8 by SSCP and nucleotide sequencing. Five out of eight pleural fluids containing adenocarcinoma showed p53 immunostaining and two of these also showed polymorphisms on SSCP and a mutation on sequencing. None of the 10 benign pleural fluids showed immunostaining for p53 or polymorphisms on SSCP. We believe that the poor sensitivity of p53 gene mutation by SSCP is mainly due to DNA from the background reactive cells ‘swamping’ the mutant DNA. We do not advocate its use as a diagnostic aid.
Desmin detection in FNAB samples of rhabdomyosarcoma: an immunocytochemical study
Authors: Pohar‐Marin‐ek Z. , Srebotnik‐Kirbi‐ I.
Published: March 2003

Desmin detection in FNAB samples of rhabdomyosarcoma: an immunocytochemical study

We performed immunocytochemical (ICC) staining for desmin on 65 fine needle aspiration biopsies from 45 patients with rhabdomyosarcoma, using the avidin‐biotin‐peroxidase complex method (ABC), and two types of antibodies, D33 and DE‐R‐11. The material was fixed either in ether‐alcohol or in Delaunay's solution. The ABC method was applied to Papanicolaou stained slides, without destaining. We compared the quality of staining on fresh, routinely prepared slides vs archival material and the quality of staining on smears vs cytospins. In 20 cases, D33 and DE‐R‐11 were applied to a pair of slides from the same tumour sample in order to see if there was any difference in their ability to recognize desmin. Desmin was positive in all 18 cases in which ICC staining was performed at the same time diagnoses were given. Among the 27 cases where ICC staining was carried out on archival material, seven were negative. Slides from four of these cases were 20 or more years old and negative reaction could be attributed to heating of slides before coversliping and/or to uneven distribution of desmin immunoreactivity in tumours. The second reason was probably the cause of negative reactions in cases from 1985 and 87. The type of slide preparation had no influence on the quality of staining. However, results were easier to read on cytospins because cells were more evenly distributed. Finally, our results proved that there was no significant difference between D33 and DE‐R‐11 in their ability to recognize desmin.
Microfilariae in association with neoplastic lesions: report of five cases
Authors: Gupta S. , Sodhani P. , Jain S. , Kumar N.
Published: March 2003

Microfilariae in association with neoplastic lesions: Report of five cases

Microfilariae and adult filarial worms have occasionally been detected in association with neoplastic lesions in cytological smears. The presence of microfilariae along with neoplasms is generally regarded as a chance association, yet some authors suggest that such parasitic infestations may be a causative factor for tumourigenesis. There are only a few reported cases in cytology literature documenting this association. We report the presence of microfilariae in routine cytology smears from one benign and four malignant tumours. Microfilariae could not be identified on histopathology available in four of these cases.
The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas
Authors: Bonzanini M. , Gilioli E. , Brancato B. , Cristofori A. , Bricolo D. , Natale N. , Valentini A. , Dalla Palma P.
Published: March 2003

The cytopathology of ductal carcinomain situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas

The existence of cytological findings that discriminate ductal carcinoma in situ (DCIS) of the breast from invasive ductal carcinoma (IDC) has not been unanimously accepted and the role of fine needle aspiration cytology (FNAC) remains controversial. We report the cytological findings of a large series of FNAC from histologically proven DCIS compared with those of ductal carcinomas having a different extent of the invasive component. The association of high cohesiveness of atypical cells and absence of tubular aggregates showed good sensitivity (SE) and specificity (SP) for the diagnosis of DCIS vs IDC. The simultaneous presence of necrotic background, atypical cells with abundant eosinophilic cytoplasm and a low percentage of single malignant cells resulted in low sensitivity but high specificity and positive predictive value (PPV) for differential cytological diagnosis of DCIS vs IDC.
The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia
Authors: Al‐Awadhi R. , Byrne M. , Coleman D. V.
Published: March 2003

The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia

It has been known for some time that only a proportion of the cells on the smear‐taking device is transferred to the slide. This can give rise to errors in reporting although the smear may have been taken correctly. This study was undertaken to identify a quick and simple method of improving the accuracy of the Papanicolaou test. A conventional smear and five additional smears were obtained from 62 women attending a Genito‐Urinary Medicine clinic. The cell content of the conventional smears and the additional smears was compared. Dyskaryotic cells were detected both in the conventional smear and in the first and second additional smears from 22 women. Dyskaryotic cells were detected in the first and second additional smears only in five women. Thus, the conventional smear failed to detect biopsy‐confirmed cervical abnormality in these women. A cell count of the first additional smear in the five cases where the conventional smear was negative showed that they contained, on average, 310 dyskaryotic cells. The preparation of one additional cervical smear per cervical scrape could significantly increase the accuracy of the cervical smear test by 11% (P=0.025, McNemar’s test).
Fine needle aspiration cytology of thyroid nodules: how accurate is it and what are the causes of discrepant cases?
Authors: DE VOS TOT NEDERVEEN CAPPEL R. J. , BOUVY N. D. , BONJER H. J. , VAN MUISWINKEL J. M. , CHADHA S.
Published: March 2003

Fine needle aspiration cytology of thyroid nodules: how accurate is it and what are the causes of discrepant cases?

Fine‐needle aspiration cytology (FNAC) is widely accepted as the most accurate, sensitive, specific and cost‐effective diagnostic procedure in the assesment of thyroid nodules and helps to select people preoperatively for surgery.

The purpose of this study was to evaluate the results of thyroid FNAC in our institution and to determine the reasons for discrepancies between the cytological and histological diagnosis. We evaluated the cytological and histological results of 254 FNACs obtained from 231 patients who underwent subsequent thyroid surgery. All of the material was blindly reviewed for quality control, by one experienced cytopathologist. All FNACs were carried out under ultrasound guidance. The cytological diagnosis was classified as benign, suspicious, malignant or unsatisfactory.

The definitive histological study showed benign lesions in 195 of the 231 patients (84%). A benign diagnosis based on FNAC was correct in 105 of the 108 benign cases (97%). FNACs diagnosed as `suspicious' resulted in a distribution of 49 benign (79%) and 13 malignant (21%) diagnoses. FNAC showed malignancy in 34 cases (13%) and in only one case did the final histology differ from cytology (correlation 97%). The percentage of FNACs that were inadequate for diagnosis was 20%. Review of cytological and histological slides did not lead to any change in the original diagnosis.

Our study revealed a cytological‐histological discrepancy (2%) in only 4 out of 231 cases over a period of 10 years, due to either a diagnostic or sampling error.
Papillary neoplasms of the breast: clues in fine needle aspiration cytology
Authors: GOMEZ‐ARACIL V. , MAYAYO E. , AZUA J. , ARRAIZA A.
Published: March 2003

Papillary neoplasms of the breast: clues in fine needle aspiration cytology

Papillary neoplasms of the breast include a wide spectrum of mammary lesions. The differential diagnosis of benign and malignant lesions can be problematic not only cytologically, but also histopathologically. Aspiration smears can demonstrate that cytological differentiation is feasible. A retrospective study of 30 cases of papillary tumour of the breast, 15 papillary carcinomas and 15 papillomas, was performed to find the cytological differences between the pathologies. Cytological samples of papillary carcinomas were characterized by an abundance of cellular material, three‐dimensional papillary clusters without fibrovascular connective tissue cores, small papillae arranged in cell balls, tall columnar cells and isolated naked nuclei. Numerous haemosiderin‐laden macrophages were seen. There were no eosinophilic bipolar cytoplasmic granules, bipolar naked nuclei or apocrine metaplasia.

In the papillomas there was less material; the papillae had cohesive stalks surrounded by columnar cells in a honeycomb pattern. We also found fewer small papillae and isolated columnar cells. In addition, the presence of apocrine metaplasia and bipolar naked nuclei was noted.

We suggest that papillary carcinoma of the breast can be diagnosed by cytology and differentiated from papilloma.
Method of producing tissue sections from endometrial scrapings
Authors: ONO M. , SHIINA Y. , SAKUMA K. , INOUE H.
Published: March 2003

Method of producing tissue sections from endometrial scrapings

Endometrial cytology is important not only for observing cytological findings, but also for assessing histological architecture. Therefore, we attempted to produce a histological preparation from the sample using an automatic fixation apparatus (ACF 1000) which employs a membrane filter method.

After observation of the cytological features, the cover slip was removed and a paraffin‐embedded section was prepared.

Producing a histological section from a cytological specimen prepared with the ACF 1000 apparatus was more useful and easier than with the techniques described to date. Peelability of the cell was avoided by using a silane‐coated membrane filter. Observation of the same cell cluster as that observed in the cytological sample was also facilitated in the histological section by this technique.
Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas
Authors: VERMA KUSUM , KAPILA KUSUM
Published: March 2003

Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas

This retrospective study was carried out to review the cases diagnosed as pleomorphic adenoma in major or minor salivary glands and determine the difficulties encountered on typing this tumour on fine needle aspiration cytology (FNAC). Over a 19‐year period (1982–2000) 488 pleomorphic adenomas were diagnosed on FNAC from different sites (parotid – 372 cases, submandibular – 95 cases; oral cavity – 21 cases). Histology was available in 232 cases. Twenty‐nine cases where a histological diagnosis of pleomorphic adenoma was made but the cytological diagnosis was variable were also reviewed. In 216 of the 232 cases a good cytohistological correlation was available. On review only 4 of the 16 cases initially diagnosed as pleomorphic adenoma on FNAC where the histology revealed a different tumour were categorized as pleomorphic adenoma, while 3 each were classified as adenoid cystic carcinoma and benign tumour ?type, and 2 each were diagnosed to be muco‐epidermoid carcinoma, monomorphic adenoma and acinic cell carcinoma. On review of the FNAC smears from 29 cases where a histological diagnosis of pleomorphic adenoma was available while the cytological diagnosis was variable, only 11 (38%) were categorized as pleomorphic adenoma. In the majority of the remaining cases the cytological diagnosis did not alter markedly, 7 of 10 cases where the tumour could not be typed on cytology initially could not be typed even on review. In conclusion, FNAC is an ideal, fairly accurate preoperative procedure for the diagnosis of pleomorphic adenomas. Certain diagnostic problems occur in differentiating pleomorphic adenomas from adenoid cystic carcinoma, monomorphic adenoma and mucoepidermoid carcinoma. Carcinoma ex‐pleomorphic adenoma is difficult to identify on FNAC and in our series all 4 such cases on histology were considered benign on cytology.
Bethesda 2001
Authors: SMITH J. H. F.
Published: March 2003

The Bethesda system (TBS) for reporting cervical/vaginal cytological diagnoses was originally developed in 1988 at a National Cancer Institute (NCI) workshop convened to consider the benefits of increased standardization in the diagnostic reports provided by cytology laboratories.1 It rapidly gained acceptance in laboratory practice in the USA and beyond2,3 and three years later the NCI sponsored another workshop to assess the use of TBS in practice and consider areas for improvement.4 Subsequently an illustrated guide was published.5
Fine needle aspiration cytology of minor salivary gland tumours of the palate
Authors: Sahai Kavita , Kapila Kusum , Dahiya Sonika , Verma Kusum
Published: March 2003

Fine needle aspiration cytology of minor salivary gland tumours of the palate

This retrospective study was carried out to review aspirates from minor salivary gland tumours of the palate and to assess the problems encountered in their diagnosis, especially the cytological diagnosis of newer entities such as polymorphous low grade adenocarcinoma (PLGA). Fifty‐five cases of palatal salivary gland tumours aspirated over a period of 16 years were reviewed. Histology was available in 26 cases. Pleomorphic adenoma (27 cases) was the most common benign cytodiagnosis. Eleven aspirates were malignant tumours of which eight cases were adenoid cystic carcinoma and three cases were mucoepidermoid carcinoma. Seven cases were diagnosed on fine needle aspiration as suggestive of PLGA. However histological confirmation was available in only one of these cases. Concordance between the initial and revised typings of the tumours was seen in only 28 cases (54%) in the present study. Initially 18 of the 51 tumours (35.3%) could not be typed; and after review, only three could not be typed. Three cases of oncocytoma could be diagnosed on review only. Palatal salivary gland tumours, although relatively uncommon, are difficult to diagnose cytologically. This is more so in cases of newer entities such as PLGA, as their cytological diagnosis is still not well characterized.
The evolution of environmentally‐cued pupal colour in swallowtail butterflies: natural selection for pupation site and pupal colour
Authors: HAZEL WADE , ANTE SANDRA , STRINGFELLOW BEN
Published: March 2003

1. Environmentally‐cued pupal colour in swallowtail butterflies has been hypothesized to evolve as a consequence of (a) the evolution of a preference for pupation sites above the ground that vary in colour and (b) natural selection for crypsis on such sites.

2. This hypothesis was tested by comparing the field survival of green and brown Papilio polyxenes Fabr. pupae placed on green or brown pupation sites that were either above the ground on near the ground.

3. Green pupae on green sites above the ground had a significantly higher probability of survival than did all other pupal colour and pupation site combinations.

4. Pupae on sites above the ground were more likely to be preyed upon during the day, whereas those on sites near the ground were more likely to be preyed upon during the night, suggesting that variation in nocturnal and diurnal predation influences the evolution of pupation site preference.

5. To the extent that diurnal predators use colour vision to locate prey, diurnal predation should favour environmentally‐cued pupal colour.
Effects of water mites on the damselfly Ceriagrion tenellum
Authors: ANDRÉS JOSÉ A. , CORDERO ADOLFO
Published: March 2003

1. Water mite parasitism is expected to have an important effect on damselfly survivorship and reproductive success, because mites drain considerable amounts of body fluids from their hosts. This study tests the effect of water mite parasitism in a marked population of the damselfly Ceriagrion tenellum during 1995 (individuals marked as mature adults) and 1996 (individuals marked as tenerals).

2. Almost all teneral individuals were parasitized (98%) and mites were aggregated strongly on some individuals. Parasite load increased during the season.

3. Parasites had no effect on the probability of recapture of hosts as mature adults. The average daily survival rate of lightly‐ and heavily‐parasitized individuals, estimated with Jolly's stochastic method, did not differ significantly.

4. In 1995 parasites had a significant effect on host mating success. The probability of mating was about 25% lower for heavily‐parasitized males than for lightly‐parasitized males. Lightly‐parasitized males also mated more times than heavily‐parasitized males, even if heavily‐parasitized males lived longer. In 1996, parasitism did not have an effect on male mating success. In both years mites had no effect on female lifetime mating success.

5. These results indicate that water mite parasitism does not reduce damselfly survivorship, but it could reduce male mating success in some circumstances. Further long‐term studies are needed, especially in populations with a lower incidence of parasitism.
Diet breadth and host plant diversity of tropical‐ vs. temperate‐zone herbivores: South‐East Asian and West Palaearctic butterflies as a case study
Authors: FIEDLER KONRAD
Published: March 2003

1. Data on host plant associations of butterflies (Papilionoidea, excluding Hesperiidae) from two biogeographical regions were used to investigate (1) whether tropical herbivores are more narrowly specialized with regard to host plant choice than those of northern temperate zones, and (2) whether tropical butterflies show a greater diversity of host plant affiliations.

2. There was no evidence for a more restricted diet breadth of tropical butterflies, with diet breadth being measured as number of host plant families used per species. In the families Papilionidae, Pieridae, and Nymphalidae, host plant ranges of West Palaearctic and South‐East Asian species are similar, whereas in one speciose group within the Lycaenidae, the Polyommatini, tropical species are significantly more polyphagous.

3. Diet breadth also differs among higher butterfly taxa. While Papilionidae, Pieridae, the nymphalid subfamilies Satyrinae, Morphinae, Libytheinae and Apaturinae, as well as the temperate‐zone Polyommatini in the Lycaenidae are composed predominantly of host specialists, the degree of polyphagy is higher among the remaining nymphalid subfamilies and in many lycaenids. These results challenge strongly the view that tropical herbivores are generally more specialized in this regard than herbivores of higher latitudes. Rather, chemical constraints and phylogenetic conservatism shape host plant associations in many taxa in such a way that differences between temperate and tropical representatives are slight.

4. Host plant diversity, measured as the number of plant families used per butterfly family and by application of the log‐series model, is much higher in South‐East Asian Nymphalidae and Lycaenidae (the two largest families) than in their Western Palaearctic relatives. No such differences are observed in the Papilionidae and Pieridae (the two smaller families). Besides effects of sample size, the strong association of papilionid and pierid butterflies with plants characterized by a small set of classes of secondary plant compounds might generally restrict their capability to utilize a broader taxonomic range of host plants.

5. The results indicate that high floral diversity can be reflected by higher diversity of host plant affiliations of herbivores, but taxonomic idiosyncrasies render it difficult to draw generalized conclusions.
Does flooding favour galling insects?
Authors: Ribeiro Katia T. , Madeira João. A. , Monteiro Ricardo F.
Published: March 2003

New Perspectives is intended to allow the communication of comments, viewpoints, and speculative interpretation of issues in ecology pertinent to entomology. Comments, viewpoints, or suggestions arising from published papers intended to fuel discussion and debate are also welcome. Contributions should be as concise as possible, normally not exceeding two thousand words. Formal research reports will not be acceptable, but summarized novel data, suitably supported by statistics, may be allowed. The use of the active voice will be permitted.
Using superparasitism by a stem borer parasitoid to infer a host refuge
Authors: Edwards Owain R. , Hopper Keith R.
Published: March 2003

Abstract. 1. Macrocentrus cingulum Reinhard (Hymenoptera: Braconidae), a parasitoid of the European corn borer, Ostrinia nubilalis, and the Asian corn borer, O. furnacalis (Lepidoptera: Pyralidae), has high fecundity but has been reported to parasitize a low proportion of host larvae. This was corroborated in field collections: in Hebei (China) and Delaware (U.S.A.), M. cingulum parasitized only 15 and 25%, respectively, of hosts collected.

2. Because M. cingulum females cannot oviposit through plant tissue, they must parasitize hosts either before they have bored into stalks or while they are near entrance holes, so that at any one time, many Ostrinia larvae may be unavailable to M. cingulum. This refuge, together with fluctuations in abundance of foraging M. cingulum females, may explain why M. cingulum parasitizes relatively few Ostrinia larvae.

3. To test this hypothesis, levels of superparasitism were measured in the field. Low parasitism resulting from a refuge for host larvae should cause high rates of superparasitism in hosts outside the refuge.

4. Because M. cingulum is polyembryonic, the number of parasitoids per host does not indicate the level of superparasitism. Random amplified polymorphic DNA markers were used to determine the number of different genotypes emerging from each host. The resulting frequency distributions were fitted to those expected under random oviposition to estimate the proportion of Ostrinia larvae unavailable to M. cingulum.

5. In the samples from Hebei and Delaware, the level of superparasitism was much higher than expected by chance if all hosts were available. Fitting the frequencies of genotypes per host to a Poisson distribution, the authors estimated that 74–82% and 69–74% of host larvae were unavailable to M. cingulum in these collections, respectively. This means that M. cingulum parasitized 60–84% and 82–95% of available hosts in these collections, respectively. These levels of parasitism contrast strongly with the 15–25% found when all hosts were assumed available for oviposition.

6. Genetic distances of M. cingulum within and between hosts did not differ, allowing rejection of the hypothesis that high levels of superparasitism resulted from a female laying several eggs in the same host.

7. The hypothesis that M. cingulum parasitizes few Ostrinia larvae because many larvae are in a refuge explains these data and previously published information better than other hypotheses that have been suggested.
Altered dispersal behaviour in parasitised aphids: parasitoid‐mediated or pathology?
Authors: Chow A. , Mackauer M.
Published: March 2003

1. Several hypotheses concerning modified dispersal behaviour in aphids parasitised by aphidiine wasps (Hymenoptera: Braconidae: Aphidiinae) were tested in the laboratory. Behavioural changes may be host‐mediated, parasitoid‐mediated, or a by‐product of trauma and pathology.

2. Mummification site varied with parasitoid species. Pea aphids (Acyrthosiphon pisum) parasitised by Aphidius ervi, Aphidius pisivorus, Monoctonus paulensis, and Praon pequodorum mummified near the aphids’ preferred feeding sites on bean plants, but those parasitised by Ephedrus californicus often died and mummified outside the colony, away from the plants.

3. Parasitism by E. californicus had a progressive effect on the behaviour of pea aphids. Approaching death, aphids lost motor control and frequently dropped off the host plant when disturbed. Dropped aphids were unable to return to the feeding site and mummified elsewhere. The proportion of aphids mummifying outside the colony increased with mummy density.

4. Mummification site was not influenced by the presence within the same colony of aphids parasitised by different species of aphidiine wasps.

5. The evidence does not support the hypothesis that mummification site selection in E. californicus is determined by a host‐ or a parasitoid‐mediated change in aphid dispersal behaviour. Association‐specific differences in the dynamics of larval development and growth between aphidiine species provide an equally valid and possibly more general explanation of mummification behaviour.
Diversity and abundance of insect herbivores foraging on seedlings in a rainforest in Guyana
Authors: Basset YveS.
Published: March 2003

1. Free‐living insect herbivores foraging on 10 000 tagged seedlings representing five species of common rainforest trees were surveyed monthly for more than 1 year in an unlogged forest plot of 1 km2 in Guyana.

2. Overall, 9056 insect specimens were collected. Most were sap‐sucking insects, which represented at least 244 species belonging to 25 families. Leaf‐chewing insects included at least 101 species belonging to 16 families. Herbivore densities were among the lowest densities reported in tropical rainforests to date: 2.4 individuals per square metre of foliage.

3. Insect host specificity was assessed by calculating Lloyd’s index of patchiness from distributional records and considering feeding records in captivity and in situ. Generalists represented 84 and 78% of sap‐sucking species and individuals, and 75 and 42% of leaf‐chewing species and individuals. In particular, several species of polyphagous xylem‐feeding Cicadellinae were strikingly abundant on all hosts.

4. The high incidence of generalist insects suggests that the Janzen–Connell model, explaining rates of attack on seedlings as a density‐dependent process resulting from contagion of specialist insects from parent trees, is unlikely to be valid in this study system.

5. Given the rarity of flushing events for the seedlings during the study period, the low insect densities, and the high proportion of generalists, the data also suggest that seedlings may represent a poor resource for free‐living insect herbivores in rainforests.
Field studies on flooding and survival of overwintering large heath butterfly Coenonympha tullia larvae on Fenn’s and Whixall Mosses in Shropshire and Wrexham, U.K.
Authors: Joy J. , Pullin A. S.
Published: March 2003

1. Peatland rehabilitation projects may involve large increases in water levels if Sphagnum‐based vegetation is to be restored over areas where vegetation has largely been destroyed by commercial peat‐cutting processes. While this can result in the creation of cotton‐sedge tussocks Eriophorum vaginatum on which large heath butterfly Coenonympha tullia larvae live, the water level changes can also lead to these tussocks being subjected to long periods of winter flooding.

2. Field trials were carried out over two winters (1996–97 and 1997–98) (1) to test laboratory predictions of the survival of C. tullia larvae under wet and dry conditions, (2) to record the behavioural responses of larvae to flooding, and (3) to determine whether vertebrate predation affected larval survival significantly.

3. Field trials confirmed the results from earlier laboratory work in that they showed that the submergence of overwintering C. tullia larvae has a marked impact on their survival. During the 1996–97 winter, 35% of the larvae placed in wet areas survived compared with 63% placed in dry areas. During the 1997–98 winter, none of the C. tullia larvae placed in wet areas survived compared with 54% of the larvae placed in dry areas. Because the depth of flooding in the wet areas was much greater in the 1997–98 winter than in the 1996–97 winter, the results from this study may reflect the survival rates of wild C. tullia larvae under moderate (1996–97 data) or severe (1997–98 data) levels of flooding.

4. The behavioural data from the field also support earlier laboratory findings and suggest that C. tullia can move in order to stay above the water surface. No evidence was found that vertebrate predation was a significant factor affecting larval survival.

5. These results suggest that raised water levels threaten C. tullia populations, but that the maintenance of suitable E. vaginatum tussocks in drier areas may ensure that a proportion of the C. tullia population survives even the wettest years.
Effects of food plant and group size on predator defence: differences between two co‐occurring aposematic Lygaeinae bugs
Authors: Tullberg Birgitta S. , Gamberale‐Stille Gabriella , Solbreck Christer
Published: March 2003

1. The role of food plant and aggregation on the defensive properties of two aposematic sympatrically occurring seed bugs, Tropidothorax leucopterus and Lygaeus equestris (Lygaeinae, Heteroptera), was investigated. Larvae reared on seeds either of their natural host plant Vincetoxicum hirundinaria (Asclepiadaceae) or of sunflower Helianthus annuus were subjected to predation by chicks.

2. The two species differ in their dependency on the host for their defence. Lygaeus equestris was better defended on its natural host plant than on the alternative food, as indicated by fewer attacks, lower mortality, and predator avoidance after experience. No such effect of food plant could be found for T. leucopterus, suggesting the existence of alternative defences in this species.

3. The number of attacks was lower when host plant‐fed larvae of both species were presented in groups.

4. The discussion concerns how major components of an aposematic syndrome, such as host plant chemistry, insect colouration, and aggregation, are integrated with other life‐history traits to form alternative lifestyles in L. equestris and T. leucopterus.
Humidity‐terminated diapause in the tropical braconid parasitoid Microplitis demolitor
Authors: Seymour Jamie E. , Jones Rhondda E.
Published: March 2003

1. Microplitis demolitor, a solitary braconid parasitoid of Helicoverpa armigera and Helicoverpa punctigera, uses an increase in relative humidity to signal the end of diapause and the re‐establishment of direct development.

2. Photoperiod and temperature changes appear not to have a direct influence on the duration or termination of diapause in this species.

3. Once diapause termination is signalled, the adult parasitoids emerge approximately 38 days later.

4. The cue for diapause termination in M. demolitor is different from that used by its hosts and ensures that the parasitoid emerges to find a population of nonmigrating hosts.

5. It appears that the cocoon surrounding the diapausing parasitoid plays a role in diapause termination; parasitoids emerge earlier from diapause if the cocoon is removed but the weight of the intact cocoon does not appear to influence the length of time the parasitoid is in diapause.
Structure of insect communities inhabiting old‐growth forest specialist bracket fungi
Authors: Komonen Atte
Published: March 2003

1. This paper describes the structure of the insect communities inhabiting two old‐growth forest specialist bracket fungi, Amylocystis lapponica and Fomitopsis rosea. To study the consequences of old‐growth forest fragmentation on community structure, non‐fragmented and fragmented forest areas in eastern and southern Finland were compared.

2. Both fungal species are inhabited by more than 50 insect species. The most abundant species in the A. lapponica community is a melandryid beetle Hallomenus sp., and in the F. rosea community a tineid moth Agnathosia mendicella. The occurrence of several nationally or globally rare species underscores the importance of specific insect microhabitats, such as the specialist fungi A. lapponica and F. rosea, for the persistence of specialised insects in old‐growth forests.

3. The species composition in both fungal species differs greatly from each other. The food webs are characterised by one numerically dominant host‐specific primary fungivore, which implies that fungivorous species inhabiting bracket fungi may be more specialised on a particular host than is generally thought.

4. The community structure was the same in the highly fragmented and in the non‐fragmented study areas, probably because fragmentation has occurred relatively recently.
Male‐biased sex ratios in mature damselfly populations: real or artefact?
Authors: Stoks Robby
Published: March 2003

1. There is ongoing controversy about whether biased sex ratios in diploid insect populations are real or an artefact caused by different behaviours and/or different catchability of the sexes. This was tested by monitoring two field and three semi‐natural populations of the damselfly Lestes sponsa.

2. Capture–mark–recapture data showed that population size estimates were about twice as large for males as for females at both field sites. Independent estimates of the sex ratios based on total numbers of males and females captured supported the male bias.

3. Males had higher recapture probabilities than females due to longer times between successive visits in females. Because the same pattern was found in the semi‐natural populations, the longer intervals in females are no artefact due to their lower detectability.

4. Theoretical models show that the strong temporary emigration of females tends, if anything, to overestimate female population sizes and that the heterogeneity of recapture probabilities observed in males tends to underestimate male population sizes. Hence, behavioural differences between the sexes do not cause an artificially male‐biased sex ratio.

5. Spatial data show that operational sex ratios are male biased at the pond but become female biased in the plots further away from the shoreline; however because of the decrease in densities away from the shoreline, this does not result in a global even sex ratio.

6. Spatial data, temporary emigration patterns, and independent estimates suggest strongly that the male‐biased sex ratios in mature damselfly populations are real.
Host plant growth characteristics as determinants of abundance and phenology in jumping plant‐lice on downy willow
Authors: Hodkinson Ian D. , Bird Jeremy M. , Hill Jane K. , Baxter Robert
Published: March 2003

1. Salix lapponum host plants at an upper altitudinal site differed significantly in size, structural density, phenology, growth performance, and spatial isolation from those growing at a lower site.

2. Plant differences were paralleled by significant differences in psyllid population density and phenology parameters, with psyllid population density, percentage of catkins occupied, and phenological development relatively lower or retarded at the upper site. Population densities at the upper site, nevertheless, remained high.

3. Plant measurements were good predictors of insect density, often explaining up to 73% of the variance in abundance among plants at a given site.

4. Sets of four plant characters identified by best subsets regression were better predictors of psyllid density and development than single factors, although differences were often not great and the combinations of characters selected by multiple regression sometimes differed from the best single predictors.

5. Best single predictors of psyllid density on catkins were measurements of plant size, particularly height, length, and basal stem diameter. Shoot density and catkin phenology were occasionally important but plant isolation and prior growth performance were less important.

6. By contrast with density, age structure of the psyllid population was predicted best from plant phenological measurements, notably catkin phenology.
Population level correlation between pre‐alighting and post‐alighting host plant preference in the Glanville fritillary butterfly
Authors: Schöps Katrin , Hanski Ilkka
Published: March 2003

1. In many populations of the Glanville fritillary butterflyMelitaea cinxia, ovipositing females exhibit a post‐alighting preference for one of the potential host plant species available. The work reported here aimed to establish whether females with different post‐alighting preferences can discriminate between their host plant species prior to alighting, and whether pre‐alighting and post‐alighting preferences are correlated at the population level.

2. Alighting and oviposition events were recorded for groups of females from six populations in greenhouse and field experiments.

3. Landing frequencies did not change with experience, indicating thatM. cinxiafemales did not learn from previous encounters with host plants.

4. Females from populations exhibiting post‐alighting preference searched efficiently for their host plants in the sense that they landed mainly on the species on which they oviposited predominantly. Pre‐alighting and post‐alighting preferences were correlated at the population level.

5. The correlation between pre‐alighting and post‐alighting preferences helps to explain why in nature, where the host plants often occur in distinct patches, females are more likely to colonise habitat patches in which their preferred host plant is abundant.
Autumnal moth – why autumnal?
Authors: Tammaru Toomas , Tanhuanpää Miia , Ruohomäki Kai , Vanatoa Alo
Published: March 2003

1. As for some other spring‐feeding moths, adult flight of Epirrita autumnata (Lepidoptera: Geometridae) occurs in late autumn. Late‐season flight is a result of a prolonged pupal period. Potential evolutionary explanations for this phenological pattern are evaluated.

2. In a laboratory rearing, there was a weak correlation between pupation date and the time of adult emergence. A substantial genetic difference in pupal period was found between two geographic populations. Adaptive evolution of eclosion time can thus be expected.

3. Metabolic costs of a prolonged pupal period were found to be moderate but still of some ecological significance. Pupal mortality is likely to form the main cost of the prolonged pupal period.

4. Mortality rates of adults, exposed in the field, showed a declining temporal trend from late summer to normal eclosion time in autumn. Lower predation pressure on adults may constitute the decisive selective advantage of late‐season flight. It is suggested that ants, not birds, were the main predators responsible for the temporal trend.

5. Egg mortality was estimated to be low; it is thus unlikely that the late adult period is selected for to reduce the time during which eggs are exposed to predators.

6. In a laboratory experiment, oviposition success was maximal at the time of actual flight peak of E. autumnata, however penalties resulting from sub‐optimal timing of oviposition remained limited.