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The flow duration curve (FDC) is the cumulative distribution function, which represents the relationship between the frequency and magnitude of streamflow, and the precipitation duration curves (PDC) follows the same principle. Nowadays, the correlation between the shape of PDC and FDCs, their respective physical control factors including human activities, and their fitting conditions in unmeasured catchments across China have not been fully understood. In this paper, daily precipitation and streamflow data with 30 years records from 224 hydrological stations in the middle and lower Yangtze River basin were chosen to fit PDC and FDCs through gamma distribution. Framework was proposed for modelling FDCs to analyse the relationship, similarity, regional patterns and response mechanism of fitting parameters between PDC and FDCs, dividing the streamflow time series into fast and base flow and stations into three categories in consideration of human activities to attribute the shapes of PDC and FDCs to catchment meteorological and geographical characteristics and physical processes under natural conditions. Results indicate that the parameters of PDC and certain FDCs (TFDC, FFDC, SFDC) share similar spatial patterns but vary for the different duration and interactions of the processes. The climate and catchment characteristics such as extreme properties of precipitation, base flow index (BFI), Pmax*αp and concentration ratio index (CIM) will influence the shape of PDC and FDCs. The relationship between BFI and SFDC/TFDC can be better reflected in "Regulated watersheds", while CIM/Pmax*αp and PDC/FFDC in "watersheds in the mainstream" are more related. This paper provides a deeper understanding and more accurate way of the application of these parameters in describing and predicting hydrological processes and estimation of PDC and FDCs in unmeasured catchments, and can be applied to more future research about processes based on catchment rainfall‐runoff responses and physical controls. [ABSTRACT FROM AUTHOR]

BACKGROUND: Eucryptorrhynchus brandti (Harold) is a destructive wood‐boring pest of tree of heaven, Ailanthus altissima, in China. At present, the management of E. brandti relies exclusively on frequent applications of synthetic insecticides. Environmentally friendly alternatives to the use of synthetic insecticides would be beneficial. A trunk trap net (TTN), an adhesive trap (AT), and an adhesive trunk trap net (ATTN) were evaluated in their ability to capture E. brandti. RESULTS: Significantly greater laboratory weevil recapture rates were found using the ATTN (78%) than using the TTN (8%) and AT (0%). In total, 45% of marked weevils were captured by the ATTN, an eight‐fold increase in catch rates using the TTN in mark‐release‐recapture field trials in 2017. No marked weevils were captured by the AT. Field trials in 2017 and 2018 showed that the ATTN captured six to seven times more wild weevils than using the TTN. CONCLUSION: Adhesive Trunk Trap nets (ATTNs) were more effective in capturing E. brandti adults than Trunk Trap nets (TTNs). These results support the use of the ATTN as an eco‐friendly tool for the integrated management of E. brandti. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The production capacity and application of plastic films in China have increased dramatically with the rapid development of agricultural greenhouse and plastic tunnels. Although the effects of films on crop management have received much attention, only a few studies have considered their effects on insect pests. Here, we investigated the developmental and demographic parameters of an insect pest of economic significance Aphis gossypii Glover (Hemiptera: Aphididae) in yellow, purple, blue, red and clear plastic films, when feeding on cucumber plants. The fecundity of the aphids under blue and red films was significantly lower compared to purple, yellow, or the clear. The red film significantly decreased the intrinsic rate of increase, finite rate of increase, net reproduction rate, and gross reproductive rate of the aphids compared to the clear. Red and blue films reduced the age-specific fecundity and reproductive value of A. gossypii compared to the clear. In general, the red films could be used to retard the population growth of A. gossypii in large-scale agricultural greenhouses. [ABSTRACT FROM AUTHOR]

BACKGROUND Eucryptorrhynchus scrobiculatus is a major pest of tree of heaven, Ailanthus altissima, in China. Damage caused by E. scrobiculatus has increased as beetle populations have expanded. We developed a trunk trap net (TTN) and two modified TTNs, that is, a TTN with a wire ring (TTN‐WR) and a TTN with a spongy cushion (TTN‐SC), and evaluated their ability to capture E. scrobiculatus in plantations of A. altissima. RESULTS: We obtained significantly higher laboratory weevil recapture rates using the TTN‐WR and TTN‐SC (98 and 95.3%, respectively) than using the TTN (65.3%). In total, 84.8 and 85.8% of marked weevils were captured by the TTN‐WR and TTN‐SC, respectively; 1.52‐ and 1.54‐fold greater than the catch rates using a TTN in mark–release–recapture field trials. Similarly, we captured significantly more wild weevils using the TTN‐WR and TTN‐SC (2.02‐ and 2.03‐fold more weevils) than using the TTN. Further field trials showed that the TTN‐SC treatment significantly reduced densities of weevils and damage to tree of heaven in stands. CONCLUSION: Our results revealed that the TTN‐SC is clearly effective for capturing E. scrobiculatus. TTN‐SC may be used as an alternative for E. scrobiculatus management with less or no insecticide. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The invasive species Spartina alterniflora are widely distributed on the coastline of China. In this study, three common physical control treatments for S. alterniflora were simulated in the laboratory environment. The results showed that "mowing + flooding" (MF) and "mowing + ploughing" (MP) treatments eradicated S. alterniflora completely during the 60-day experiment. However, the flooding and ploughing treatments and the decay of S. alterniflora would change the biogeochemical feature of the sediment, resulting in the abnormal release of nutrients. Spearman's correlation analysis and water quality analysis results showed that the average concentrations of NH 4 +-N (1.80 mg/L) and TP (0.43 mg/L) in MF treatment, as well as NH 4 +-N (1.49 mg/L), NO 3 −-N (0.95 mg/L), and NO 2 −-N (0.35 mg/L) in MP treatment greatly increased due to the migration and transformation of nutrient. Parallel factor analysis (PARAFAC) confirmed that three components of dissolved organic matter (DOM) and their rising in overlying water were related to the decomposition of S. alterniflora and the disturbed sediment, which could increase the risk of eutrophication in offshore water bodies. In addition, three physical control treatments changed the structure and composition of the bacterial community by altering the colonization of specific bacteria and the sediment microenvironment. Mantel test analysis and structural equation modeling (SEM) showed that the variation of key nutrients in MF and MP treatments had significant impacts on bacterial community structure. This study revealed the effects of physical control of S. alterniflora on migration and transformation mechanism of nutrients in coastal wetlands and the structure of the bacterial community. [Display omitted] • Physical control treatments for S. alterniflora show different ecological impacts. • "Mowing + flooding" and "mowing + ploughing" may increase endogenous release risk. • The persistent flooding conditions decrease bacterial richness and diversity. • Decayed S. alterniflora enhances bacterial richness and diversity after ploughing. [ABSTRACT FROM AUTHOR]

In Northern China, the tree-of-heaven root weevil (TRW), Eucryptorrhynchus scrobiculatus (Motschulsky) (Coleoptera: Curculionidae), is a serious borer pest of Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) (tree-of-heaven) is an important tree species for landscapes and afforestation. This study evaluates the efficacy of trunk trap nets (TTN), thiacloprid spray (TS), and cypermethrin spray (CS) alone, and in combination with TTN and thiacloprid or cypermethrin spray (TTNTS or TTNCS) for controlling TRW in A. altissima plantations in 2016–2018 in three sites (Haojiaqiao, Wutongshu, and Taojiajuan), which are located near Lingwu city in Ningxia, China. TTN, TTNTS, and TTNCS treatments significantly reduce marked TRW captures (more than 93% with respect to the untreated trees) and wild TRW captures in population monitoring trunk trap nets (MTTN) deployed in stands (more than 55% with respect to the untreated trees). Further field trials demonstrate that these TTN, TTNTS, and TTNCS treatments significantly reduce damage to A. altissima in stands; there are no significant differences between TTN and combination treatments. In addition, significantly more TRW are captured in MTTN within Taojiajuan than within Haojiaqiao or Wutongshu in field trials 2018. There were no significant differences between sites in 2016 and 2017. This study indicates that the TS and CS treatments used had very little to no impact on TRW populations and tree health in the timeframe examined. TTN alone are clearly effective for suppressing populations of TRW and stabilizing A. altissima tree health. This physical control technique, using TTN, could be sufficient to manage TRW on tree-of-heaven with no insecticide. [ABSTRACT FROM AUTHOR]

• Mowing + shading can efficient control Spartina alterniflora. • Mowing alone could not efficient suppress Spartina alterniflora. • The effectiveness of both methods was independent of the timing of the treatments. Plant invasions greatly threaten native biodiversity and ecosystem health, and measures to effectively control and eradicate invasive plants are urgently needed. Spartina alterniflora has invaded large areas of coastal China as well as many other countries, and caused tremendous ecological and economic problems. To develop measures for effectively controlling the invasion of this species, a field experiment was conducted to test the effectiveness of two methods, i.e. mowing alone, and mowing + shading, on suppressing the growth and reproduction of S. alterniflora , with no shading and mowing as the control. The treatments were applied at five different times, i.e. in May, July, August, October, and November of 2013, and measurements were done at the end of the growing season in both 2013 and 2014. Overall, mowing alone could not effectively suppress S. alterniflora at the end of the second growing season (in 2014); instead, this method promoted both the sexual and asexual reproduction of this invasive plant. The mowing + shading treatment, however, highly effectively suppressed the growth and reproduction of S. alterniflora , and no asexual individuals (ramets) or seedlings were observed at the end of the second growing season. The effectiveness of both methods for controlling S. alterniflora was independent of the timing of the treatments in the long term. We propose the use of mowing + shading to effectively eradicate S. alterniflora in China and possibly also in other counties in future, and the selection of the timing for the treatment according to the cost and convenience. [ABSTRACT FROM AUTHOR]