Performance of a Native Butterfly and Introduced Moth on Native and Introduced Lineages of Phragmites australis

This study examined the performance of Poanes viator (Edwards) (Hesperiidae), a native North American skipper, and Rhizedra lutosa (Hübner) (Noctuidae), an introduced moth, reared on native and non-native, invasive lineages of Phragmites australis. Poanes viator is a generalist on monocots and larvae were also fed leaves of Zizania aquatica, a native macrophyte that the skipper commonly uses as a host plant. Larval survival and duration, pupal weight, and pupation time were compared for P. viator feeding on leaf tissue and R. lutosa feeding on rhizomes of either native or introduced plants. We also tested an artificial diet supplemented with P. australis rhizome powder as a potential food for rearing other stalk and rhizome boring Lepidoptera. In experiments using excised plant tissues, some individuals of both species fed and developed to the pupal stage on native and introduced plants, but overall, larval survival rates were low. Plant species/haplotype identity did not cause strong differences in larval survival for either species. However, P. viator larvae only pupated when feeding on native plants (Zizania aquatica and native P. australis haplotypes), whereas R. lutosa successfully pupated on both native and introduced P. australis. Although larval survival was low, 100% of P. viator and 95% of R. lutosa that reached the pupal stage emerged as adults. Rhizedra lutosa larvae fed an artificial diet supplemented with P. australis rhizome powder had significantly greater survival and pupal weights, and shorter pupation times than larvae fed rhizomes only. Several specialist Lepidopteran species are being considered for approval as biological control agents for the non-native P. australis haplotype, and the convenience and increased larval performance make this artificial diet a good alternative for rearing organisms.

Performance of ecological concrete-based ecological systems (ECBESs) for nitrogen removing from synthetic farmland drainage water

Efficiency and mechanism of nitrogen removals by ecological concrete-based ecological systems (ECBESs) were investigated in this study. Results show that ECBES performed well on denitrification. Ecological concrete as matrix of the ecological was positive for nitrogen removing according to that the experimental ECBESs achieved a greater TN removal compared to the control system. This result was possibly attributable to a higher biomass and increased bacteria diversity in ECBESs, since ecological concrete could be a carrier of microorganism. Vegetation could further improve TN removals. Acorus calamus L. - ECBES, Ipomoea aquatica Forsk - ECBESs, Oenanthe javanica (Bl.) DC. - ECBES and Zizania aquatica - ECBES achieved an average TN removal of 67.87%, 81.93%, 76.18%, 66.22%, respectively, in a test cycle. Nitrogen transformation in the ECBESs indicated the occurrence of ammonification, nitrification and denitrification. Moreover, bacteria related to nitrogen transformation was identified from the bio-film immobilized on the ecological concrete.

Studies on Effects of Several Wetland Plants on Eutrophic Water Purification

Effectiveness of combinations of seven different ecotypes of wetland plants including Thalia dealbata, Iris tectorum, Acorus calamus,Zizania aquatica, Nymphaea tetragona,Georgi, Myriophyllum aquaticum, Thalia dealbata purifying water was investigated by hydrostatic simulation experiment method. The research showed that combinations of various wetland plants had significant purification effects on eutrophic water body, plant community was stable, and plants grew well. Chemical Oxygen Demand (COD) removal efficiencies of various combinations were higher than 97%, and 25.9% higher than that of the blank control group; the average highest total phosphorus (TP) removal efficiency of plant combinations was 97.6%. Compared with COD and TP, Total nitrogen( TN)removal efficiency was lower, ranging from 90.4% to 83.1%.Different wetland plants had different purification effectiveness for different pollutant. The combination N+Z+A+ZI had the highest TNremoval efficiency, reaching 90.4%. Combinations N+Z+A+ZI and N+Z respectively won the first and second place in the disposal of TP,reaching 99.68%, 99.34%. For Chemical Oxygen Demand COD removal, the combination N+Z+C+T did the best and the highest removal efficiency reached 97.6%. Fuzzy comprehensive evaluation method is used to select the following combinations with stronger capacities of removing N and P in sewage: N+Z+A+ZI, N+Z, N+Z+C+T. They can be promoted and applied in purification of eutrophic water body in ecological projects.