Comparative morphology of cephalic exocrine glands among castes of the black ant Lasius niger.

The glandular system is crucially involved in main aspects of ant social life. The function of glands has been primarily studied in the workers (the non-reproductive individuals in a colony). In contrast, little information is available on queens (the reproductive females in a colony) or males in spite of the obvious functional differences between these castes. Here we report a comparison of the general morphology of the mandibular, propharyngeal and postpharyngeal glands between the three castes of the black ant Lasius niger. The analysis clearly shows that all these cephalic glands differ in relative size between castes and suggests a link between gland structure and its behavioral role in queens, workers and males. In particular, males present a hypertrophied mandibular gland. This is consistent with the fact that these glands might be the source of the sex pheromone in this caste. By contrast, queens exhibited the most developed postpharyngeal glands. This is consistent with the production of particular cues by queens for workers to help them to distinguish between reproductive and non-reproductive females. Finally, the propharyngeal glands were most developed in the worker caste and of similar relative size in males and queens. Their function is still enigmatic.

Spatial pattern of floral morphology: a possible insight into the effects of pollinators on plant distribution

Pollination syndromes involve convergent evolution towards phenotypes composed of specific scents, colours or floral morphologies that attract or restrict pollinator access to reward. How these traits might influence the distributions of plant species in interaction with pollinators has rarely been investigated. We sampled 870 vegetation plots in the western Swiss Alps and classified the plant species into seven blossom types according to their floral morphology (wind, disk, funnel, tube, bilabiate, head or brush). We investigated the environmental features of plots with functional diversity (FD) lower than expected by chance alone to detect potential pollination filtering and related the proportions of the seven blossom types to a combination of environmental descriptors. From these results, we inferred the potential effect of the pollinator on the spatial distribution of plant species. The vegetation plots with significantly lower FD of blossom types than expected by chance were found at higher altitudes, and the proportions of blossom types were strongly patterned along the same gradient. These results support a biotic filtering effect on plant species assemblages through pollination: disk blossoms became dominant at higher altitudes, resulting in a lower FD. In harsh conditions at high altitudes, pollinators usually decrease in activity, and the openness of the disk blossom grants access to any available pollinator. Inversely, bilabiate blossoms, which are mostly pollinated by bees, were more abundant at lower elevations, which are characterised by greater abundance and diversity of bees. Generalisation through openness of the blossom could be advantageous at high elevations, while specialisation could be a successful alternative strategy at lower elevations. The approach used in this study is purely correlative, and further investigations should be conducted to infer the nature of the causal relationship between plant and pollinator distributions.

Occurrence, morphology and ultrastructure of the Dufour gland in Melipona bicolor Lepeletier (Hymenoptera, Meliponini)

The occurrence, morphology and ultrastructure of the Dufour gland in Melipona bicolor Lepeletier, 1836 are presented. The Dufour gland is not present in workers. In virgin queens the gland cells show characteristics of low activity, which are described in the text. In physogastric queens the gland epithelium is higher and the cells more active than in virgin queens, showing numerous basal plasmic membrane invaginations impregnated by an electrondense material, increased apical invaginations and accumulation of substances that will be released to the gland lumen in the subcuticular space. Therefore, the data show that the Dufour gland is more developed in physogastric than in virgin queens, indicating a possible involvement of the Dufour gland in the reproduction of this species.

Taxonomy and morphology of Apsil Malloch (Diptera, Muscidae, Coenosiinae, Coenosiini) with new records, description of a new species and a key to identification

Taxonomy and morphology of Apsil Malloch (Diptera, Muscidae, Coenosiinae, Coenosiini) with new records, description of a new species and a key to identification. Apsil Malloch (Diptera, Muscidae, Coenosiinae, Coenosiini) includes 10 species, most of them described from Chile, but some also from Argentina. Five of them and one new species were found at the California Academy of Sciences collection (San Francisco, California) during the course of a project developed in that institution. Almost all material studied was collected in Chile, mainly by M. E. Irwin, during the year of 1966. Brief diagnosis of the known studied species (A. apicata Malloch, A. atripes Malloch, A. dilata Malloch, A. maculiventris Malloch (female described for the first time) and A. spatulata, Malloch), the description of A. mallochi, sp. nov. and a key for the identification of all known species are given. Color illustrations of some morphological characters make easier the recognition of the species. New geographic records were assigned.

Assessment of a new MRI classification of spinal stenosis based on cross-sectional morphology of the dural sac : FM2

Introduction: Quantitative measures of degree of lumbar spinal stenosis (LSS) such as antero-posterior diameter of the canal or dural sac cross sectional area vary widely and do not correlate with clinical symptoms or results of surgical decompression. In an effort to improve quantification of stenosis we have developed a grading system based on the morphology of the dural sac and its contents as seen on T2 axial images. The grading comprises seven categories ranging form normal to the most severe stenosis and takes into account the ratio of rootlet/CSF content. Material and methods: Fifty T2 axial MRI images taken at disc level from twenty seven symptomatic lumbar spinal stenosis patients who underwent decompressive surgery were classified into seven categories by five observers and reclassified 2 weeks later by the same investigators. Intra- and inter-observer reliability of the classification were assessed using Cohen's and Fleiss' kappa statistics, respectively. Results: Generally, the morphology grading system itself was well adopted by the observers. Its success in application is strongly influenced by the identification of the dural sac. The average intraobserver Cohen's kappa was 0.53 ± 0.2. The inter-observer Fleiss' kappa was 0.38 ± 0.02 in the first rating and 0.3 ± 0.03 in the second rating repeated after two weeks. Discussion: In this attempt, the teaching of the observers was limited to an introduction to the general idea of the morphology grading system and one example MRI image per category. The identification of the dimension of the dural sac may be a difficult issue in absence of complete T1 T2 MRI image series as it was the case here. The similarity of the CSF to possibly present fat on T2 images was the main reason of mismatch in the assignment of the cases to a category. The Fleiss correlation factors of the five observers are fair and the proposed morphology grading system is promising.

The influence of environmental conditions on immune responses, morphology and recapture probability of nestling house martins (Delichon urbica)

Nestling birds produced later in the season are hypothesized to be of poor quality with a low probability of survival and recruitment. In a Spanish population of house martins (Delichon urbica), we first compared reproductive success, immune responses and morphological traits between the first and the second broods. Second, we investigated the effects of an ectoparasite treatment and breeding date on the recapture rate the following year. Due probably to a reverse situation in weather conditions during the experiment, with more rain during rearing of the first brood, nestlings reared during the second brood were in better condition and had stronger immune responses compared with nestlings from the first brood. Contrary to other findings on house martins, we found a similar recapture rate for chicks reared during the first and the second brood. Furthermore, ectoparasitic house martin bugs had no significant effect on the recapture rate. Recaptured birds had similar morphology but higher immunoglobulin levels when nestlings compared with non-recaptured birds. This result implies that a measure of immune function is a better predictor of survival than body condition per se.

External morphology of the immature stages of Neotropical heliconians: VIII. Philaethria wernickei (Röber) (Lepidoptera, Nymphalidae, Heliconiinae)

The external features of egg, larva, and pupa of Philaethria wernickei (Röber, 1906) are described and illustrated, based upon light and scanning electron microscopy.

Pineus boerneri Annand, 1928 (Hemiptera, Adelgidae) - a new species to Brazil: morphology of eggs, nymphs and adults

Pineus boerneri Annand, 1928 (Hemiptera, Adelgidae) _ a new species to Brazil: morphology of eggs, nymphs and adults. Pineus boerneri represents the first Adelgidae species recorded in Brazil. This aphid species forms extensive colonies on branches and trunk of Pinus spp., with apterous oviparous females, eggs and nymphs covered with white wax. The aim of this research is to study the morphology of eggs, nymphs, and adults to provide useful data for species identification in order to solve taxonomic issues. The study was based on morphometric data and optical and scanning electron microscopy images. First instar nymphs are active and can be easily distinguished from the others by their elongate minute yellowish body; well developed legs bearing a pair of sensorial setae at the apex of the second tarsomere; and antenna with three segments with a large rhinarium and distinct apical setae on the last segment. From the second to the fourth instar, nymphs are sessile, with round red body; they loose the third antennal segment and its sensorial structures, as well as the setae on the second tarsomere. The oviparous female is reddish-brown, with round body with about 0.76 mm diameter; legs reduced; antennae one-segmented; ovipositor distinct; numerous wax glands are present, mainly on the head. Accurate characterization of the species and distinction of the nymphal instars of P. boerneri were made possible by canonical analysis of morphometric data and morphological characters.

Comparative morphology of the mandibles of female polistine social wasps (Hymenoptera, Vespidae, Polistinae)

Comparative morphology of the mandibles of female polistine social wasps (Hymenoptera, Vespidae, Polistinae). Diversity of mandibular forms in female polistines is explored and compared among 116 species of all polistine genera. Inferences about function are made and discussed based on observed form differences. Mandible length and width measurements are analyzed for a subset of polistine species plus two vespines and two eumenines. A variable expressing the ratio between these variables is also considered in morphometric analyses. The following mechanical interactions among mandible structural elements are highlighted: opposition and crossing of mandibles' apical teeth at the middle of the closing trajectory; shearing action of the apical teeth against mesial denticles of the opposite mandible; shearing action of the mandible anterior margin against the ventral margin of the clypeus. In the genera Agelaia and Angiopolybia, exceptionally developed mesial mandibular structures may be related to necrophagy. In some epiponine genera, poorly developed mesial denticles and strong torsion of mandibles may be partially related to use of short wood fibers in nest construction as advanced by Sarmiento (2004). The considerable morphological variation found across the subfamily Polistinae is certain to be important in taxonomic and phylogenetic studies at the genus and species levels.

Comparative morphology of the spermathecae of some species of Chrysomya Robineau-Desvoidy and Cochliomyia Townsend (Diptera, Calliphoridae)

Comparative morphology of the spermathecae of some species of Chrysomya Robineau-Desvoidy and Cochliomyia Townsend (Diptera, Calliphoridae). Little is known about the morphology of the chitinized structures of the spermathecae of the Calliphoridae. In this work, the spermathecae of Chrysomya albiceps Wiedemann, 1819, C. megacephala Fabricius, 1794, Cochliomyia macellaria Fabricius, 1775 and C. hominivorax Coquerel, 1858 are described and illustrated. The occurrence in one species of four spermathecae, an atypical form for blow flies, was recorded for the first time. The analysis of these structures will allow a better understanding of this group as well as provide taxonomic characters for future phylogenetic studies.

Intraepithelial carcinoma of the oesophagus: endoscopic morphology.

The endoscopic detection of 18 "early" hypopharyngo-oesophageal carcinomas, has allowed us to perform a detailed study of the morphological correlation between endoscopy and histology (in 10 cases). We have thus defined 4 different endoscopic types of intraepithelial carcinomas; their morphology, mapping and evolution are greatly variable. In high risk groups (heavy smoking and alcohol consumption, ENt-cancer) the multicentricity of intraepithelial carcinomas (80%) entails a thorough endoscopic screening of the upper digestive tract (mouth, pharynx, oesophagus) and of the lower respiratory tract (larynx, trachea and bronchi).

External morphology of the adult of Dynamine postverta (Cramer) (Lepidoptera, Nymphalidae, Biblidinae) and patterns of morphological similarity among species from eight tribes of Nymphalidae

External morphology of the adult of Dynamine postverta (Cramer) (Lepidoptera, Nymphalidae, Biblidinae) and patterns of morphological similarity among species from eight tribes of Nymphalidae. The external structure of the integument of Dynamine postverta postverta (Cramer, 1779) is based on detailed morphological drawings and scanning electron microscopy. The data are compared with other species belonging to eight tribes of Nymphalidae, to assist future studies on the taxonomy and systematics of Neotropical Biblidinae.

Lagochile emarginata (Gyllenhal): morphology of immature and imago, and biological records (Coleoptera, Scarabaeidae, Rutelinae)

Lagochile emarginata (Gyllenhal): morphology of immature and imago, and biological records (Coleoptera, Scarabaeidae, Rutelinae). The last larval instar and pupa of Lagochile emarginata are described. Pupa of the genus Lagochile Hoffmannsegg, 1817 is described for the first time. Redescription of the imago, clarifications on the morphology of immature Scarabaeoidea and biological notes are presented.

External morphology of the immature stages of Neotropical heliconians: IX. Dione glycera (C. Felder & R. Felder) (Lepidoptera, Nymphalidae, Heliconiinae)

External morphology of the immature stages of Neotropical heliconians: IX. Dione glycera (C. Felder & R. Felder) (Lepidoptera, Nymphalidae, Heliconiinae). The biology of the Andean silverspot butterfly Dione glycera (C. Felder & R. Felder, 1861) is still poorly known. This species is restricted to high elevations in the Andes, where the immature stages are found in close association with species of Passiflora belonging to the section Tacsonia (Juss.) Harms, especially P. tripartida var. mollissima (Kunth), which is grown for subsistence by villagers. Herein we describe and illustrate the external features of the egg, larva and pupa of D. glycera, based on light and scanning electron microscopy.

Worker morphology of the ant Gnamptogenys striatula Mayr (Formicidae, Ectatomminae) in different landscapes from the Atlantic Forest domain

Morphological traits, such as size and shape, may reflect a combination of ecological and evolutionary responses by organisms. Ants have been used to evaluate the relationship between the environment and species coexistence and morphology. In the present study, we analyzed the morphology of workers of Gnamptogenys striatula Mayr in different landscapes from the Atlantic Domain in southeastern Brazil, focusing on the variation in the morphological attributes of these populations compared to those from a dense ombrophilous forest. Eighteen morphological traits of functional importance for interactions between workers and the environment were measured to characterize the size and shape of the workers. In general, the results show that ants of urban areas possess some morphological attributes of smaller size, with highly overlapped morphological space between the populations in forested ecosystems. Further, some of the traits related to predation were relatively smaller in modified land areas than in the populations from preserved areas of dense ombrophilous forest. These results help broaden the knowledge regarding morphological diversity in G. striatula, suggesting that the characterization of the morphology may be important to quantify the effects of land use on morphological diversity, and presumably, to facilitate the use of ants as biological indicators.