Function, homology and terminology in insect wings

Abstract. The history of current systems of wing nomenclature is summarized, and the underlying principles reviewed. The homologies of wing areas are clarified, with particular reference to the functions and positions of longitudinal lines of bending in the wings. Distinction is drawn between flexion-lines, primarily aerodynamic in function, and fold-lines, which are primarily concerned with wing-folding. Of these the claval furrow - a flexion-line - and the jugal fold-line are, when recognizable, nearly constant in position, and are hence valid area boundaries and useful landmarks in vein identification. The vannal fold-line and the median flexion-line are variable in position, and hence unsatisfactory area boundaries. The nature and functioning of fold- and flexion-lines in the axilla of Locusta are described and illustrated, and names are proposed. Conflicting aspects of commonly-used systems of wing terminology are evaluated; and illustrated recommendations are put forward for consistent naming of veins, branches and wing areas.     

Homology and function in the wings of Heteroptera

Abstract. The homology of veins and other wing characters in Heteroptera is reviewed in the light of palaeontology and new functional studies. A cladogram is given for the higher taxa of Hemiptera. It is probable that the vannus is an autapomorphy of Auchenorrhyncha+Heteropteroidea; that the leading edge vein of heteropteran fore- and hindwings is C+Sc; that Rs cannot be distinguished from R; that the hamus is part of M; that the glochis is a secondary structure. The difficulty of defining a vein is stressed. The functional significance of the hemielytron, cuneal fracture and longitudinal flexion lines is discussed. A preliminary ground-plan for Heteroptera wings is presented.     

Foods and feeding habits of wild and captive Sirenia

The Sirenia along with the elephants and hyraxes form the Super-Order Paenungulata. They are the only fully aquatic mammalian herbivores and are represented by three species of manatees (Trichechidae), the dugong and the now extinct, Steller's sea cow (Dugongidae). Sirenians are non-ruminant herbivores that have specialized hind-gut fermentation in a large paired caecum at the juncture of the large and small intestines. The stomach is relatively small and is characterized by a unique cardiac gland which contains most of the digestive-enzyme secreting cells. Little is known of the digestive physiology of sirenians. The metabolic rate of the manatee is very low in comparison to other mammals and may even represent the lowest weight-specific metabolic rate for any mammal known. Metabolic rates for Dugong have not yet been determined. Foods and feeding habits of these species are reviewed both qualitatively and quantitatively. Manatees consume approximately 896 of their total body weight in aquatic plants daily, whereas the same value for the dugong is about 14%. Digestibilities of aquatic plants vary from 45 to 70% for manatees and a single in vitro measurement for Dugong was 83% for sea-grass. The chemical composition of various plants consumed by wild and captive sirenians are presented and their value in the nutritional ecoloev of the different species is discussed.     

Invasive wasps,not birds,dominate in a temperate honeydew system

The Avian Convergence Hypothesis states that avian–honeydew associations are likely to develop when biogeographic and/or climatic factors limit the formation of ant–honeydew associations (the dominant association in tropical ecosystems). In this study we examine a honeydew‐influenced forest system in an island archipelago where ant diversity is low but invasive Vespula wasp species (Vespidae) are present. We found honeydew production was highly seasonal, with both standing crop and 24‐h production peaking in summer. When Vespula wasps were abundant (summer and autumn) they preferentially visited infested trees and fed regularly on honeydew droplets on infested branches. Two ant species occasionally fed on honeydew. No other insects or birds were observed feeding on honeydew during the study period. With the exception of Vespula, honeydew does not appear to be a preferred food source in this community, possibly because of the range of other food resources available in surrounding forest, farmland and gardens. The abundance of Vespula wasps at the site may also have disrupted bird–honeydew associations. We suggest the Avian Convergence Hypothesis could be restated to explicitly include both nectar availability and invasive social insects as both are likely to influence bird use of honeydew.     

Habitat-Suitability Models for Cavity-Nesting Birds in a Postfire Landscape

ABSTRACT Models of habitat suitability in postfire landscapes are needed by land managers to make timely decisions regarding postfire timber harvest and other management activities. Many species of cavity-nesting birds are dependent on postfire landscapes for breeding and other aspects of their life history and are responsive to postfire management activities (e.g., timber harvest). In addition, several cavity nesters are designated as species at risk. We compare the ability of 2 types of models to distinguish between nest and non-nest locations of 6 cavity-nesting bird species (Lewis's woodpecker [Melanerpes lewis], black-backed woodpecker [Picoides arcticus], hairy woodpecker [P. villosus], northern flicker [Colaptes auratus], western bluebird [Sialia mexicana], and mountain bluebird [S. currucoides]) in the early postfire years for a ponderosa pine (Pinus ponderosa) forest in Idaho, USA. The 2 model sets consisted of 1) models based on readily available remotely sensed data and 2) models containing field-collected data in addition to remotely sensed data (combination models). We evaluated models of nesting habitat by quantifying the model's ability to correctly identify nest and non-nest locations and by determining the percentage of correctly identified nest locations. Additionally, we developed relative habitat-suitability maps for nesting habitat of black-backed and Lewis's woodpeckers from the best models. For all species except Lewis's woodpeckers, model performance improved with the addition of field-collected data. Models containing remotely sensed data adequately distinguished between nest and non-nest locations for black-backed woodpecker and Lewis's woodpecker only, whereas models containing both field-collected and remotely sensed data were adequate for all 6 species. Improvements in the availability of more accurate remote sensing technology would likely lead to improvements in the ability of the models to predict nesting locations. External validation with data from other wildfires is necessary to confirm the general applicability of our habitat-suitability models to other forests. Land managers responsible for maintaining habitat for cavity-nesting birds in postfire landscapes can use these models to identify potential nesting areas for these species and select areas in burned forests where postfire salvage logging is most likely to have minimal impacts on cavity-nesting bird habitats.     

Nematode‐specific PCR primers for the 18S small subunit rRNA gene

A set of polymerase chain reaction primers were designed, which amplify a c. 1 kb fragment of the 18S ribosomal DNA gene, and are specific to the phylum Nematoda. These have proven useful in isolating nematode genes from samples mixed with other biological material, particularly with application to DNA barcoding. Optimal reaction conditions are described. These primers have successfully amplified the correct fragment from a wide phylogenetic range of nematodes, and have so far generated no sequences from any other organismal group.     

The ontogeny of the platycopid Keijcyoidea infralittoralis (Ostracoda: Podocopa)

Platycopid ostracods such as the genus Keijcyoidea Malz, 1981 (Family Cytherellidae) have a unique body plan and are regarded as a phylogenetically ancient lineage. Their ontogeny, which is important in considering phylogenetical relationships, is very poorly known except for the growth of the carapace; there are nine instars including the adult, as in other podocopan groups. All appendages in all immature instars (A-8 to A-1) of Keijcyoidea infralittoralis Tsukagoshi, Okada & Horne, 2006 are described and illustrated here. The anlagen of the copulatory organs and the sexual dimorphism of carapace size appear in the sixth (A-3) instar, whereas sexual dimorphism in both the fifth and the sixth limbs, a distinctive feature of adults, is not clearly evident until the eighth (A-1) instar. Appendages are added at the moults between the second (A-7) and third (A-6), and between the fifth (A-4) and sixth (A-3) instars. The seventh limb, which platycopid ostracods have lost in the adult stage, is observed as an anlage in the sixth (A-3) and seventh (A-2) instars. During the other moults, there are no significant changes to the body plan. The ontogeny of the Platycopida is compared with that of the Podocopida, and strongly suggests that the phylogenetic position of the Platycopida is as an end-member of the Podocopa. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 213–237.     

The first British record and a new species of the superfamily Terrestricytheroidea (Crustacea, Ostracoda): morphology, ontogeny, lifestyle and phylogeny

Terrestricythere elisabethae sp. nov. is described from a semiterrestrial coastal habitat at two sites in Hampshire, southern England. It is the first record of a living population of the genus outside the Far East (north-west Pacific). Based on extensive collections and from observations of cultures, its morphology is described (including a formal definition of the unique 'visordont' hinge), as well as its ontogeny and lifestyle (encompassing habitat, life cycle, mode of life and locomotion). A further new species from Somerset, south-west England is also recorded on the basis of a single specimen but left in open nomenclature. The affinities of the Terrestricytheroidea are discussed in the context of a tentative phylogeny of podocopan Ostracoda. Both carapace and appendage characters are such as to warrant maintaining it as a separate superfamily, which is more closely related to the Cytheroidea and Darwinuloidea than to the Cypridoidea.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 142 , 253–288.