Species Radiation of Carabid Beetles (Broscini: Mecodema) in New Zealand

New Zealand biodiversity has often been viewed as Gondwanan in origin and age, but it is increasingly apparent from molecular studies that diversification, and in many cases origination of lineages, postdate the break-up of Gondwanaland. Relatively few studies of New Zealand animal species radiations have as yet been reported, and here we consider the species-rich genus of carabid beetles, Mecodema. Constrained stratigraphic information (emergence of the Chatham Islands) and a substitution rate for Coleoptera were separately used to calibrate Bayesian relaxed molecular clock date estimates for diversification of Mecodema. The inferred timings indicate radiation of these beetles no earlier than the mid-Miocene with most divergences being younger, dating to the Plio-Pleistocene. A shallow age for the radiation along with a complex spatial distribution of these taxa involving many instances of sympatry implicates recent ecological speciation rather than a simplistic allopatric model. This emphasises the youthful and dynamic nature of New Zealand evolution that will be further elucidated with detailed ecological and population genetic analyses.     

Effect of Habitat Patch Characteristics on Abundance and Diversity of Insects in an Agricultural Landscape

The objective of this study was to test for general effects of patch size, patch isolation, disturbance frequency, and patch life span, on density and diversity of organisms. We sampled predominantly herbivorous insects in 31 alfalfa fields that varied in size, isolation, frequency of disturbance by cutting, and age (number of years planted in alfalfa). Effects on insect relative density and diversity were examined at three taxonomic levels: all insects, eight separate orders, and six legume-specialist weevil species. We found that (a) more isolated alfalfa fields had higher overall insect richness, (b) fields with higher disturbance frequency had lower overall insect richness, and (c) fields of intermediate age had highest insect richness. In some cases these patterns were reflected at lower taxonomic levels, but in many cases they were not. These results are important because they indicate that, although we cannot simultaneously tailor a landscape for each of thousands of species, we may be able to produce desired effects at a more general level. Received 8 August 1997; accepted 2 January 1998.     

Spatiotemporal Analysis of Predation by Carabid Beetles (Carabidae) on Nematode Infected and Uninfected Slugs in the Field

The dynamics of predation on parasites within prey has received relatively little attention despite the profound effects this is likely to have on both prey and parasite numbers and hence on biological control programmes where parasites are employed. The nematode Phasmarhabditis hermaphrodita is a commercially available biological agent against slugs. Predation on these slugs may, at the same time, result in intraguild predation on slug-parasitic nematodes. This study describes, for the first time, predation by carabid beetles on slugs and their nematode parasites on both spatial and temporal scales, using PCR-based methods. The highest nematode infection levels were found in the slugs Deroceras reticulatum and Arion silvaticus. Numbers of infected slugs decreased over time and no infected slugs were found four months after nematode application. The density of the most abundant slug, the invasive Arion vulgaris, was positively related to the activity-density of the carabid beetle, Carabus nemoralis. Predation on slugs was density and size related, with highest predation levels also on A. vulgaris. Predation on A. vulgaris decreased significantly in summer when these slugs were larger than one gram. Predation by C. nemoralis on slugs was opportunistic, without any preferences for specific species. Intraguild predation on the nematodes was low, suggesting that carabid beetles such as C. nemoralis probably do not have a significant impact on the success of biological control using P. hermaphrodita.     

Effects of Landscape Elements on the Distribution of the Rare Bumblebee Species Bombus muscorum in an Agricultural Landscape

The regional distribution pattern of Bombus muscorum was studied in an agricultural landscape of central Germany, one of two remaining areas with the occurrence of this nationally endangered species in the Land Hesse. To determine the landscape characteristics that facilitate the occurrence of B. muscorum, grid-based observation records were analysed in a GIS environment at a regional scale. A significantly negative effect of the number of trees on the occurrence of B. muscorum and a significantly positive one of the proportion of arable land, strongly support the species’ preference for open landscapes. Yet, apart from open landscapes additional landscape features were shown to be important. A significantly positive effect of ditches in the final model revealed the importance of this landscape element for the occurrence of B. muscorum. This finding was additionally supported by recordings of nest-searching queens, nests, and flower visits along dithes. The positive effects of clover and fallow land indicate the species’ need for suitable food resources throughout the season. Because B. muscorum exhibits small foraging ranges, it is essential that landscape elements that provide nesting sites, foraging habitats and undisturbed hibernation structures are next to each other. The low numbers of individuals of B. muscorum recorded indicate that the supply of these habitat elements may have reached a critical threshold in the study region.     

The Distribution of Walleye Pollock,Theragra chalcogramma,and Conditions of its Habitat off the Southern Kuril Islands

Russian Journal of Marine Biology - Data on the spatial distribution of the Walleye Pollock, Theragra chalcogramma, and the conditions of the habitat off the southern Kuril Islands in the spawning...     

Habitat Selection by the Spur-thighed Tortoise Testudo graeca in a Multisuccessional Landscape: Implications for Habitat Management

As a result of human activities, natural Mediterranean landscapes (including agro-ecosystems) are characterised by a mosaic-like structure with habitat-patches at different successional stages. These systems have high biodiversity levels and are home to a large number of species protected by European laws whose habitats should be adequately managed. In the present work, we study habitat use from an applied point of view in the spur-thighed tortoise Testudo graeca, an endangered reptile present in semi-arid Mediterranean agro-ecosystems. Results show that, at a landscape scale, the species selects simplified vegetation structures and includes in its home range re-colonisation shrubland and small non-irrigated fields. Within the home range, habitat selection patterns vary and areas with higher vegetation cover and complexity are selected. Detected patterns are discussed in terms of the ecological requirements of the species and with a hierarchical view of resources and conditions. The implications of our findings for habitat management aimed at the conservation of the species are also discussed.     

Habitat Specificity and Variation of Coleopteran Assemblages Between Habitats in a Southern African (Swaziland) Agricultural Landscape

Assessment of Coleopteran diversity and abundance was carried out in the lowveld region of Swaziland by pitfall trapping in five distinct habitats. Additionally, the study was to ascertain if any of the families collected illustrated habitat fidelity. 18 coleopteran families, comprising 2903 individuals were collected, with an additional 29 unidentified specimens, totalling 2932 beetles. Numerically, the top five families were the Scarabaeidae (2425), Carabidae (211), Tenebrionidae (149), Nitidulidae (37) and Curculionidae (22). 66.6% of all specimens collected were harboured within the pine windbreak while the lowest number (2.6%) was collected from the mature citrus orchard. The highest proportion (77%) of scarabaeid beetles collected occurred within the pine windbreak. Habitat specificity was illustrated by one family, Meloidae, which was found only in the young orchard. Community analysis was further carried out to ascertain distribution patterns of the dominant coleopteran families. Three scarabaeid species were found only in the pine windbreak while three carabid species occurred only in the indigenous savanna. Significant differences between habitats were observed in the number of beetles collected while no significant differences were observed in terms of the number of families observed in each habitat (p<0.05). Results indicate that conservation of the various habitat patches within the mosaic studied could facilitate conservation of whole communities rather than individual species thus facilitating effective conservation of the agricultural landscape.     

Movement Behaviour of the Carabid Beetle Pterostichus melanarius in Crops and at a Habitat Interface Explains Patterns of Population Redistribution in the Field

Animals may respond to habitat quality and habitat edges and these responses may affect their distribution between habitats. We studied the movement behaviour of a ground-dwelling generalist predator, the carabid beetle Pterostichus melanarius (Illiger). We performed a mark-recapture experiment in two adjacent habitats; a large plot with oilseed radish (Raphanus sativus) and a plot with rye (Secale cereale). We used model selection to identify a minimal model representing the mark-recapture data, and determine whether habitat-specific motility and boundary behaviour affected population redistribution. We determined movement characteristics of P. melanarius in laboratory arenas with the same plant species using video recording. Both the field and arena results showed preference behaviour of P. melanarius at the habitat interface. In the field, significantly more beetles moved from rye to oilseed radish than from radish to rye. In the arena, habitat entry was more frequent into oilseed radish than into rye. In the field, movement was best described by a Fokker-Planck diffusion model that contained preference behaviour at the interface and did not account for habitat specific motility. Likewise, motility calculated from movement data using the Patlak model was not different between habitats in the arena studies. Motility (m² d⁻¹) calculated from behavioural data resulted in estimates that were similar to those determined in the field. Thus individual behaviour explained population redistribution in the field qualitatively as well as quantitatively. The findings provide a basis for evaluating movement within and across habitats in complex agricultural landscapes with multiple habitats and habitat interfaces.     

Contrasting Responses of Saproxylic Insects to Focal Habitat Resources: The Example of Longhorn Beetles and Hoverflies in Belgian Deciduous Forests

Although both saproxylic longhorn beetles and hoverflies benefit from the presence of woody substrates for reproduction, they differ in their requirements for floral resources and for microbiotopes of overmature and senescent trees. This led us to expect contrasting responses between the two species groups in relation to these essential resources. We examined this prediction in 22 mature oak- and beech-dominated stands of southern Belgium by relating their species assemblages to local vegetation structure and composition, altitude and landscape composition. Stands were organised in pairs as a function of their overall dead wood supply. Free-hanging window traps, stump emergence traps and Malaise traps produced 30 longhorn beetle species (1637 individuals) and 106 hoverfly species (3020 individuals). Paired-comparisons controlling for annual variation in captures showed that, unlike saproxylic hoverflies, stands with dead wood hosted more species and individuals of longhorn beetles. Accordingly, the two species groups were found to be independent on ordination axes, responding to different sets of environmental conditions. While stands dominated by oaks with a high snag volume were highly favoured by longhorn beetles, saproxylic and threatened syrphids were limited to open-stands with large trees and a well-developed, species rich herb layer providing the floral resources required for their reproduction. Our results suggest that, when defining criteria to identify or restore important habitats for saproxylic insect conservation, variables related to different aspects of dead wood supply should not be the only criteria taken into account.     

Distribution and Abundance of the World's Smallest Primate,Microcebus berthae,in Central Western Madagascar

The distribution of most recently discovered or described lemur species remains poorly known, but many appear to have small geographical ranges, making them vulnerable to extinction. Research can contribute to future conservation actions on behalf of these species by providing accurate information on local distribution and abundance. The distribution of the world’s smallest primate, the endangered Madame Berthe’s mouse lemur (Microcebus berthae), is limited to the Menabe Central region of western Madagascar. This species was discovered in the 1990s, but many fundamental aspects of its ecology remain unknown. The aims of our study were therefore to determine the actual distribution of Microcebus berthae across the forests of this region, to estimate population density, and to examine the species’ response to anthropogenic activities. We established 35 1-km line transects across Menabe Central, on which we surveyed mouse lemurs by distance sampling and live trapping. Microcebus berthae does not occur in all remaining forests of this small region and its population density is highly heterogeneous, both across its geographic range and locally. Within its area of occupancy, the population of Microcebus berthae not only was distributed according to spatial heterogeneities of the habitat, but also responded to anthropogenic disturbances and varied seasonally. Our results indicate that Microcebus berthae is susceptible to habitat degradation and avoids human environments spatially. As none of the forest remnants in which the species still occurs were officially protected until recently, immediate conservation actions should focus on effectively protecting Kirindy and Ambadira forests.     

The Roles of Chemokines in Rabies Virus Infection: Overexpression May Not Always Be Beneficial

It was found previously that induction of innate immunity, particularly chemokines, is an important mechanism of rabies virus (RABV) attenuation. To evaluate the effect of overexpression of chemokines on RABV infection, chemokines macrophage inflammatory protein 1α (MIP-1α), RANTES, and IP-10 were individually cloned into the genome of attenuated RABV strain HEP-Flury. These recombinant RABVs were characterized in vitro for growth properties and expression of chemokines. It was found that all the recombinant viruses grew as well as the parent virus, and each of the viruses expressed the intended chemokine in a dose-dependent manner. When these viruses were evaluated for pathogenicity in the mouse model, it was found that overexpression of MIP-1α further decreased RABV pathogenicity by inducing a transient innate immune response. In contrast, overexpression of RANTES or IP-10 increased RABV pathogenicity by causing neurological diseases, which is due to persistent and high-level expression of chemokines, excessive infiltration and accumulation of inflammatory cells in the central nervous system, and severe enhancement of blood-brain barrier permeability. These studies indicate that overexpression of chemokines, although important in controlling virus infection, may not always be beneficial to the host.Rabies virus (RABV) is a negative-strand RNA virus belonging to the Rhabidoviridae family, genus Lyssavirus, which causes rabies (fatal encephalomyelitis) in many species of mammals (5). More than 55,000 humans die of rabies each year worldwide (26). Once clinical signs develop, rabies is always fatal (12, 53). Despite the lethality of rabies, only mild inflammation and little neuronal destruction were observed in the central nervous system (CNS) of rabies patients (31, 32). Adaptation of wild-type (wt) RABV in laboratory animals and/or cell culture leads to attenuation in phenotype, and laboratory-adapted RABVs have been used for vaccine development (1, 10). To delineate the mechanism(s) of RABV attenuation, previous studies compared the host responses to infection with either laboratory-attenuated or wt RABV (52). It was found that laboratory-attenuated RABV induced extensive inflammation, apoptosis, and neuronal degeneration, as well as induction of expression of innate immune genes in the CNS; however, wt RABV caused little or no neuronal damage and avoided the activation of expression of innate molecule genes. Other investigators also reported the induction of innate immunity in mice or neuronal cells infected with laboratory-attenuated viruses (20, 33, 37). The mostly upregulated genes in the innate immune responses after infection with attenuated RABV include genes encoding for inflammatory chemokines and type I interferon (IFN) as well as IFN-related proteins (20, 33, 378). Further studies have shown that the expression of chemokines (mRNA and proteins), particularly macrophage inflammatory protein 1α (MIP-1α; CCL3), RANTES (CCL5), and IP-10 (CXCL10), correlates with the infiltration of inflammatory cells and enhancement of blood-brain barrier (BBB) permeability (23).Chemokines are a group of small (∼8- to 14-kDa), basic, structurally related molecules that can attract inflammatory cells along concentration gradients and enhance leukocyte-endothelial cell interactions (55). The tertiary structure of chemokines is highly conserved; they contain at least four cysteine residues that form two disulfide bonds (50). Chemokines have been divided into major subfamilies on the basis of the arrangement of the two N-terminal cysteine residues, CC and CXC. CC chemokines act primarily upon monocytes, whereas CXC family members are specific for neutrophils and lymphocytes (14). Chemokines regulate cell trafficking of various types of leukocytes through interactions with G-protein-coupled receptors with seven transmembrane regions (55). Most chemokine receptors are stimulated by more than one chemokine, and one ligand can bind to more than one receptor (50). This combination of redundancy and promiscuity might act as a safety factor to ensure adequate host defenses (15, 30). Chemokines have direct antiviral activities and/or recruit inflammatory cells to the site of infection to kill virus or virus-infected cells (30, 34). However, due to their ability to direct migration of inflammatory cells, overexpression of chemokines may have detrimental effects, especially in the process of autoimmune inflammation. In an experimental autoimmune encephalomyelitis model, IP-10, monocyte chemoattractant protein 1 (MCP-1), and MIP-1α were strongly upregulated (14). Administration of anti-IP-10 antibody decreased disease incidence and severity and the infiltration of mononuclear cells into the CNS (11).In the present study, the roles of chemokines in RABV infection were further investigated by cloning and expressing MIP-1α, RANTES, and IP-10 in the genome of the RABV HEP-Flury strain. It was found that overexpression of MIP-1α decreased the pathogenicity by inducing transient expression of chemokines and infiltration of inflammatory cells into the CNS. In contrast, recombinant RABV expressing RANTES and IP-10 induced persistent and high-level expression of chemokines and extensive infiltration of inflammatory cells into the CNS, causing neurological diseases and death.     

A Species-specific Monoclonal Antibody System for Detecting the Remains of Field Slugs, Deroceras reticulatum (Muller) (Mollusca: Pulmonata), in Carabid Beetles (Coleoptera: Carabidae)

The field slug, Deroceras reticulatum (Muller), is probably the most damaging and widespread species of slug, causing severe economic losses in a broad range of crops in temperate zones throughout the world. Investigations into the role of predation in the population dynamics of this species required a biochemical system which was capable of identifying the remains of this slug in the crop contents of predators, and distinguishing them from those of other molluscs. A monoclonal antibody was developed (IgM isotype). This was capable of separating, in an enzyme-linked immunosorbent assay, D. reticulatum from the related D. caruanae (Pollonera) and all molluscs and other invertebrates tested, with the unexpected exceptions of New Zealand flatworms, Artioposthia triangulata (Deny) and the millipede Polymicrodon polydesmoides (Leach). Characterization of the antibody and assay demonstrated that the system could clearly detect as little as 11.6 ng of D. reticulatum protein in 200 mu l of buffer. Slug remains could be identified as such in the crops of the carabid predator Pterostichus melanarius Illiger for 38.1 h, while the antibody-antigen reaction declined to half of that measured immediately following consumption, after 12.9 h. A practical and highly sensitive system was therefore developed, using the first species-specific monoclonal antibody available for the investigation of predation on slugs.     

The Rove Beetles (Coleoptera, Staphylinidae) of Exposed Riverine Sediments in Scotland and Northern England: Habitat Classification and Conservation Aspects

Exposed riverine sediments (ERS) by four rivers in Scotland and northern England were sampled for beetles in 1996 and 1997. One hundred and sixty rove beetle (Staphylinidae) species lists were analysed using ordination and classification techniques in order to identify habitat groups within and between catchments and to assess which factors were affecting species assemblage distribution. There were major differences between the species assemblages of ERS by rivers of highland and lowland catchments. Within catchments, assemblage distribution was mainly influenced by the position of sites within the catchment; vegetation cover and sediment composition had less influence. The number of rove beetle habitats was not the same as those for ground and phytophagous beetle groups, indicating that conservation considerations should take into account variations in ERS habitat diversity. A considerable number of records of nationally rare and scarce rove beetle species were recorded, most on ERS by rivers and tributaries unaffected by river management or engineering.     

Spatial Variation in Fish Assemblages across small Mediterranean Drainages: Effects of Habitat and Landscape Context

Much debate about assemblage organization in stream fish may stem from analysing the effects of both local and large-scale processes on assemblage attributes over whole geographic regions. This study addresses this issue, by examining the contribution of local habitat attributes and landscape context to fish assemblage variation across small Mediterranean drainages in southern Portugal. Fish abundance and species composition was estimated in 28 sites, across 10 drainages, in both a dry year (1999) and a wet year (2001), and related to two sets of variables reflecting habitat and landscape characteristics. Fish showed responses to both sets of variables with variance partitioning indicating that landscape context had important effects on species richness whereas habitat attributes were the primary determinants of local fish abundance. In general, high species richness was associated with larger drainage area and higher rainfall variability, whereas variation in species abundances mostly reflected the influence of width, depth, conductivity, current velocity, substrate size and emergent vegetation. The relative contributions of both landscape context and habitat attributes to species richness and abundance were generally lower in 1999 than in 2001, with much less diversified species–habitat relationships being found in the former dry year. These results point to the dynamic nature of assemblage organization, emphasizing the importance of innovative, multi-scale approaches in advancing our knowledge of fish assemblage structure in Mediterranean streams.     

The Landscape of Leadership in Environmental Governance: a Case Study from Solomon Islands

Sustainability science suggests a core set of factors that foster significant change in governance, with leaders and entrepreneurs often identified as the main instigators. Discussions of leadership in governance transformations often focus on key charismatic people, underplaying contestation and the complex landscape of leadership. We present an empirical study that uses a participatory network mapping approach to provide a broader examination of leadership in integrated conservation and development. We use the Coral Triangle Initiative in Solomon Islands as an example of potential transformation in environmental governance across multiple objectives. Our analysis shows that actants, other than key individuals, enact leadership. We illustrate that a different suite of actants are providing leadership for each of the three Coral Triangle Initiative objectives. Actants can enact leadership by positively and negatively influencing different goals to varying extents. Our study illustrates the potential of broader and more nuanced understandings of leadership in environmental governance.