An understanding of the seasonal variation in the standing stock of metals and nutrients in emergent vegetation of constructed wetlands (CWs), as well as the amounts present in aboveground (AG) and belowground (BG) biomass, is crucial to their design and management. Given that biomass harvesting is a labour and time consuming operation, a paucity of information currently exists on accumulation and standing stocks in biomass in CWs, in particular in North Western European countries. To address this knowledge gap, this paper examined the seasonal variations of metals and nutrients in Phragmites australis (Cav.) Trin. ex Steudel in a CW treating municipal wastewater, with a view to identifying an optimal time for biomass harvesting of the AG vegetation. Although the AG biomass was greatest in August (1,636 ± 507 g m-2), the maximum concentrations and accumulations of metals and nutrients occurred at different times throughout the duration of the study (April to 2 November). Furthermore, with the exception of zinc and nitrogen, metals and nutrients measured in BG biomass ranged from 66% (phosphorus) to greater than 80% (nickel and chromium) of the AG biomass. This indicates that analysis of only the emergent shoots may significantly underestimate the metal and nutrient uptake and capacity of the plant. In order to effectively target the bulk of metals and nutrients, an AG harvest in late August or September is suggested.

Given the current decline of natural wetlands worldwide and the consequent negative impacts on amphibians, wetlands constructed for the treatment of wastewaters have the potential to play a role in the protection of these animals. However, there is a paucity of information regarding the value of constructed wetlands (CWs) to amphibians, particularly relating to the terrestrial phase of the life-cycle. This study compares the terrestrial habitats of natural wetlands (NWs) and CWs as refuges for the smooth newt (Lissotriton vulgaris) with the aim of developing recommendations for CWs (both new and existing) to enhance their usefulness as newt-friendly habitats. Terrestrial habitats surrounding NWs and CWs, including barriers to newt movement and features which could act as potential newt refuges, were mapped using ArcGIS. Natural wetlands had significantly more terrestrial habitat types than CWs and while woodlands at both wetland types were most likely to contain features of benefit to newts, almost twice as many grids (20 m x 20 m) in the terrestrial habitats of NWs contained features compared to those of CWs. The application of a Habitat Suitability Index resulted in seven of eight NWs compared to only two of eight CWs receiving "good" scores, the lower scores for CWs being due primarily to the presence of a barrier to newt movement. Recommendations for enhancing the design and management of CWs for smooth newts include less intensive ground maintenance, reduction of barriers to newt movement, judicious planting and the provision of additional refuges.

The malacophagous feeding behaviour of larvae of members of the family Sciomyzidae makes the group ideal for the selection of potential biological control agents of snail hosts of trematode diseases. The aim of this study was to investigate the effects of temperature (14 °C, 17 °C, 20 °C, 23 °C, and 26 °C) on the pupal and adult stages of Sepedon spinipes spinipes (Scopoli) (Diptera: Sciomyzidae). Larval prey density effects on the pupal stage and the extent of sexual dimorphism within the species are also assessed. Optimum growth conditions for the pupal stage and pre-oviposition/oviposition periods, and female fecundity are identified for mass culturing purposes. The tendency of mature third instar larvae to engage in wandering behaviour is highlighted, and the biological control implications of such behaviour are discussed. Female puparia were significantly (P<0.001) heavier than males for both larval prey densities. Such sexual dimorphism would enable the prediction of adult sex from puparial weight prior to eclosion, thereby facilitating culture establishment. The effect of three food types [honey/yeast mixture only, crushed Radix balthica (L.) (Gastropoda: Pulmonata: Lymnaeidae) only, and honey/yeast mixture plus a crushed snail] on adult longevity (laboratory conditions) was also determined and the results suggest that adults live longest when provided with a crushed snail and a honey/yeast mixture.

1. The intensification of farming practices, along with the loss and fragmentation of semi-natural habitats within agricultural areas, has contributed significantly to insect decline worldwide including flower-visiting aculeate Hymenoptera.2. In this study aculeate Hymenoptera were collected using bi-directional Malaise traps placed along farmland linear habitats across a range of farming intensities. The aim was to further our understanding of the value of farmland linear habitats to this insect group and in particular the Vespinae, an understudied subfamily.3. Overall, significantly greater aculeate Hymenoptera species richness was found on extensive than on intermediate and intensive farms. Significantly more species and specimens were collected on the side of the traps adjacent to the linear habitats compared to the side which opened onto the fields. Aculeate Hymenoptera species richness was also significantly greater in dense hedgerows than in open hedgerows. Furthermore, two out of six Vespinae species, Vespula rufa and Vespula vulgaris, had significantly more individuals on extensive than intensive farms.4. This study highlights that low-intensity farming practices and farmland linear habitats, especially dense hedgerows, may enhance aculeate Hymenoptera occurrence in agricultural areas. It also demonstrates that Malaise traps set up along linear habitats across a range of farming intensities can make a significant contribution to knowledge regarding the biodiversity value of such areas. Given that selected Vespinae species follow similar trends to aculeate Hymenoptera, the possibility of using them as simple biodiversity indicators is worthy of further exploration.

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