Dispersal capacity in the Mediterranean corn borer, Sesamia nonagrioides

Corn (Zea mays L.) borers are the primary target of Bacillus thuringiensis Berliner (Bt) transgenic maize. Management of corn borer resistance to Bt requires information on larval and adult dispersal capacities, a feature that is particularly unknown in Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), the most damaging corn borer in Spain. Larval dispersal was studied over a 3 year period by infesting plants with egg masses and dissecting the neighbouring plants 7, 14, and 32 days later to measure larval dispersal at several ages. The number and age of larvae were recorded in the dissected plants. Only mature larvae dispersed in significant numbers; they moved at least to rows adjacent to those containing the infested plant, and down the row five plants. The percentage of larvae that dispersed from the infested plant was density‐dependent. Adult dispersal was studied with directional light and pheromone uni‐traps over 5 and 3 year periods, respectively. Directional light traps were placed in the margins between Bt and non‐Bt maize fields, half oriented towards each of the two kinds of maize field. Pheromone traps were placed in the Bt and non‐Bt fields at increasing distances (0–100 m) from the border. The numbers of males and females caught in directional light traps were not different in traps oriented towards Bt or non‐Bt fields, but the number of males caught in the third flight in Bt fields was lower than in non‐Bt fields. These results suggest that males from adjacent Bt and non‐Bt fields mate indiscriminately with females emerging in any of the two kinds of maize fields. However, male movement in the third flight may not be sufficient to randomly distribute males between the two fields.     

Fish community response to the longitudinal environmental gradient in Czech deep-valley reservoirs: Implications for ecological monitoring and management

Ecological quality assessment of non-natural water bodies is, in contrast to natural systems, less developed and requires determining biological indicators that reliably reflect environmental conditions and anthropogenic pressures. This study was motivated to propose fish indicators appropriate for assessment of reservoir ecosystems in central Europe. We analysed changes in water quality, total biomass and the taxonomic, trophic and size composition of fish communities along the longitudinal axes of four elongated, deep-valley reservoirs. Due to high nutrient inputs from their catchments, the reservoirs exhibited pronounced within-system gradients in primary productivity and water transparency. Although fish communities were similar among the reservoirs and dominated by few native species, the community structure and biomass systematically changed along the longitudinal axes of the reservoirs. The biomass and proportion of planktivores/benthivores in the fish community were highest at eutrophic sites near the river inflow and declined substantially towards deep, more oligotrophic sites close to the dam. The biomass and proportion of piscivores significantly increased downstream within the reservoirs alongside improving water quality. At species level, perch Perca fluviatilis and bream Abramis brama responded most sensitively, although in opposite directions, to the longitudinal environmental gradient. The major longitudinal changes in fish community characteristics were found to be consistent between pelagic and benthic habitats. The results of this study suggest that fish communities are appropriate indicators of eutrophication and can be used for ecological quality assessment of non-natural lentic water bodies, such as reservoirs. Moreover, our results underline the necessity to consider within-system gradients in water quality and the fish community when planning sampling programmes for deep-valley reservoirs.     

GIS-based integrated evaluation of environmentally sensitive areas (ESAs) for land use planning in Langkawi,Malaysia

Extensive economic growth, tourism activities and over-exploitation of resources have become the common causes of environmental degradation in Langkawi. The sudden development leap resulting from UNESCO's recognition of Langkawi Archipelago as a Global Geopark in 2007, leads to continuous conflicts between enhancing environmental protection and meeting tourism and development needs. Environmental sensitivity evaluation is a basis upon which the concept of environmentally sensitive areas (ESAs) can be practised in order to protect the environment, regulate development activities and promote sustainable land use planning. This study embarks on evaluating and classifying environmental sensitivity as well as comparing different ESA approaches applicable for land use planning in Langkawi. A GIS-based integrated evaluation model was performed on two assessment sets (Set A and Set B) using a standard grading system and weights determined with analytic hierarchy process (AHP) method. Of these sets, the former consists of selected indicators from the Malaysian integrated ESA instrument while the latter are derived from previous eco-environmental studies conducted in China. The projected final ESA maps of Langkawi indicate spatial distribution of four environmental sensitivity classes. More highly and moderately sensitive areas are observed in Set A, accounting for 339.15 km² or 72.24% of the total land area compared to Set B with only 259.04 km² or 55.18% respectively. The results also reveal large proportion of low sensitivity areas in Set A, covering areas of 117.42 km² (25.01%). In contrast, more areas with non-sensitivity are widely distributed in Set B, occupying areas of 123.02 km² (26.20%). Taking into consideration the natural and cultural characteristics of the islands, it is suggested that Set A is a better approach to portray current environmental concerns and to coordinate future land use planning as well as fits Langkawi's aspiration in becoming a sustainable, world-class Global Geopark. This study provides beneficial information and opportunity for reasonable rearrangement of zoning and development guidelines and strategies within sensitivity areas. It promotes effective utilization of the natural resources, minimizes negative tourism impacts and adequately highlights ecosystem functions to prosper local socio-economic growth. It also represents an early step for the design of universal ESA instruments to regulate local development activities and promote sustainable land use planning in vulnerable areas at global levels.     

The Importance of Hydrodynamics for Protected and Endangered Biodiversity of Lowland Rivers

This paper examines the relationship between protected and endangered riverine species (target species) and hydrodynamics in river-floodplain ecosystems, combining ecological and policy-legal aspects of biodiversity conservation in river management. The importance of different hydrodynamic conditions along a lateral gradient was quantified for various taxonomic groups. Our results show that (i) target species require ecotopes along the entire hydrodynamic gradient; (ii) different parts of the hydrodynamic gradient are important to different species, belonging to different taxonomic groups; (iii) in particular low-dynamic parts are important for many species and (iv) species differ in their specificity for hydrodynamic conditions. Many species of higher plants, fish and butterflies have a narrow range for hydrodynamics and many species of birds and mammals use ecotopes along the entire gradient. Even when focussing only on target species, the entire natural hydrodynamic gradient is important. This means that the riverine species assemblage as a whole can benefit from measures focussing on target species only. River reconstruction and management should aim at re-establishing the entire hydrodynamic gradient, increasing the spatial heterogeneity of hydrodynamic conditions.     

The law of the sea and the prospects for deep seabed mining: The position of the European community

This article explores the options that the Norwegian government has when it comes to the management of harvesting a new resource (redfeed) in the politically tense area surrounding Svalbard. The article argues that, by preparing a blueprint regime solely for redfeed rather than allowing the resource to be a catalyst for conflict, the impacts of introducing the fishery will be less dramatic.     

Quantitative Aspects of the Development of Meloidogyne arenaria Larvae in Grapevine Varieties and Rootstocks

The development and productivity of parasitic stages of Meloidogyne arenaria were quantitatively defined in 14 varieties or rootstocks of grapevine. Mean development to maturity was related linearly to the number of degree-hours above 10 C temperature experienced from the time of penetration in all cultivars in which nematode adulthood was achieved. Averaged across varieties, 13,142 heat units were required for development of the mean individual to maturity. The standard deviation of the developing individuals about the mean, expressed as a proportion with 1 representing adulthood, did not differ with time or among varieties after 7,000 degree-hours had elapsed. Earliest egg production was observed after 7,662 degree-hours, averaged across varieties, considerably before mean development to maturity. Varieties were also ranked relative to the number of larvae establishing infection sites, and the rate of egg production per adult female. Varieties could he grouped according to their levels of horizontal resistance.     

Food distribution,dominance, and aggressive behaviors in bonnet macaques

Resource availability or distribution may affect interindividual competition in species such as primates, which forage in social groups, and several field studies suggest that dominance status predicts access to restricted food sources. Increased competition due to restricted resources may result in the intensification of aggressive behaviors. The study reported here examines the impact of manipulation of the distribution of food resources in a laboratory-housed group of bonnet macaques to assess the impact of distribution on aggressive behaviors. Food was restricted to a space which allowed access to only one or two individuals at a time or was dispersed throughout the living enclosure to allow universal access in alternating periods. During periods of clumped distribution, the monkeys obtained access to the food in order of their dominance status in the group. In addition, overall levels of aggressive behaviors increased, submissive behavior increased, and play decreased during periods of clumped distribution of food. These results confirm the findings from field studies indicating increases in agonism with restriction of food resources. These findings also have implications for primate colony management, in terms of developing strategies for minimizing intragroup aggression in captive groups.     

Larval habitat for the avian malaria vector Culex quinquefasciatus (Diptera: Culicidae) in altered mid‐elevation mesic‐dry forests in Hawai'i

Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 2001–2003 to identify all potential larval mosquito habitat within two 100+ ha mesic‐dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; ‘Ainahou Ranch and Mauna Loa Strip Road. At ‘Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally‐occurring sites. Additionally, moderate‐size (≈20–22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger‐ and smaller‐volume habitat (<50%). Less than 20% of trees surveyed at ‘Ainahou Ranch had treeholes and few mosquito larvae were detected. Aerial surveys at ‘Ainahou Ranch detected 56% (95% CI: 42–68%) of the potential larval habitat identified in ground surveys. At Mauna Loa Strip Road, Cx. quinquefasciatus larvae were only found in the rock holes of small intermittent stream drainages that made up 20% (5 of 25) of the total potential larval habitat. The volume of the potential larval habitat did not influence the probability of mosquito occurrence at Mauna Loa Strip Road. Our results suggest that Cx. quinquefasciatus abundance, and subsequently avian malaria, may be controlled by larval habitat reduction in the mesic‐dry landscapes of Hawai'i where anthropogenic sources predominate.