Selection of Monitoring points for the Number and Infectivity of the Main Vectors of West Nile Virus in the Volgograd Region

Relevance. Since 1999, the incidence of West Nile fever has been recorded in the Volgograd region. The main vectors of West Nile virus in Russia are Cx mosquitoes. pipiens L. and Cx. modestus Fic. An objective assessment of the entomological situation and infection rate of these species within the framework of epidemiological surveillance of West Nile fever is possible only in biotopes with sufficiently high numbers of mosquitoes; therefore, the choice of sampling points is an urgent task. Purpose of the study. Analysis of the West Nile virus main vectors - mosquitoes Cx. pipiens L. and Cx. modestus Fic. average number, occurrence and infection rate at the various open biotopes of the Volgograd region to justify the choice of optimal points for entomological monitoring. Materials and methods. The catching and accounting of the mosquitoes’ number was carried out in 2015–2019 from May to August in the third decade of each month in a floodplain forest, at a personal plot, a summer cottage and on bank of water body. To catch mosquitoes, automatic traps Mosquito Magnet Executive and LovKom-1 were used. The accounting unit was the number of mosquitoes collected in both traps per trap-night. The average number, the index of occurrence and infection rate were determined by generally accepted methods. Detection of West Nile virus RNA in samples of mosquito pool suspensions was performed by RT-PCR using the AmpliSense WNV-FL reagent kit. The results were statistically processed using Microsoft Excel 2016 (Microsoft Corporation, USA). Results. In the 2015-2019 period, 17468 mosquitoes of the genus Culex: 8258 species – Cx. pipiens L., 9210 species – Cx. modestus Fic. were collected in over than 80 trap nights at the selected stationary points of the Volgograd region. Average number of Cx. pipiens L. was: in the floodplain forest – 4.6 individuals per 1 trap-night; at the personal plot – 183.9; at the summer cottage – 30.2; on the bank of water body – 194.3. Average number of Cx. modestus Fic. was: in the floodplain forest – 5.2 individuals per 1 trapnight; at the personal plot – 8.3; at the summer cottage – 2.5;on the bank of water body – 444.6. Occurrence index Cx. pipiens L. was highon the bank of water body and at the personal plot (47.1% and 44.5%, respectively), much lower – at the summer cottage (7.3%) and in the floodplain forest (1.1%). Level of WNV infection among Cx. pipiens L.on a personal plot was 5.4%, on a summer cottage – 3.6%,on the bank of water body – 2.2%. No infected samples were found among Cx. pipiens L. collected from the floodplain forest. WNV RNA in samples from mosquitoes Cx. modestus Fic. found only in individuals caughton the bank of water body. Their infection rate was 1.2%. Discussion. Ecological plasticity of Cx. pipiens L. mosquitoes allows them to live in settlements and near water bodies. Mosquitoes of the species Cx. modestus Fic. do not fly away from ponds, breeding places. Conclusion. High numbers and occurrence of the Cx. pipiens L. mosquitoes were observed at a personal plot within the city andon the bank of water body, Cx. modestus Fic. –on the bank of water body. WNV RNA positive samples were detected from mosquitoes collected at the personal plot, the summer cottage andon the bank of water body. To monitor the number and infection rate among Cx. pipiens L., points of registration and sampling should be placed in open stationson personal plots in settlements, banks of water bodies and summer cottages. We recommend to carry entomological monitoring for Cx. modestus Fic. out onlyon the banks of water bodies along the water's edge in reed thickets. The placement of the main WNV vectors number and infection rate monitoring points in the floodplain forest is not advisable.

Impacts of a large hydroelectric dam on the Madeira River (Brazil) on floodplain avifauna

ABSTRACT Hydroelectric dams represent an important threat to seasonally flooded environments in the Amazon basin. We aimed to evaluate how a dam in the Madeira River, one of the largest tributaries of the Amazonas River, affected floodplain avifauna. Bird occurrence was recorded through simultaneous passive acoustic monitoring in early successional vegetation and floodplain forest downstream from the dam and upstream in sites impacted by permanent flooding after dam reservoir filling. Species were identified through manual inspection and semi-automated classification of the recordings. To assess the similarity in vegetation between downstream and upstream sites, we used Landsat TM/ETM+ composite images from before (2009-2011) and after (2016-2018) reservoir filling. Downstream and upstream floodplain forest sites were similar before, but not after dam construction. Early successional vegetation sites were already different before dam construction. We recorded 195 bird species. While species richness did not differ between upstream and downstream sites, species composition differed significantly. Ten species were indicators of early successional vegetation upstream, and four downstream. Ten species were indicators of floodplain forest upstream, and 31 downstream. Seven of 24 floodplain specialist species were detected by the semi-automated classification only upstream. While we found some bird species characteristic of early successional vegetation in the upstream sites, we did not find most species characteristic of tall floodplain forest. Predominantly carnivorous, insectivorous, and nectarivorous species appear to have been replaced by generalist and widely distributed species.

Evolution of relict floodplain forest in river stretches of Western and Central Europe as affected by river infrastructure networks

We studied the impact of infrastructure networks on relict floodplain forest along three stretches of the Upper Rhine (Kembs-Efringen-Kirchen, Strasbourg-Kehl and Beinheim-Iffezheim) and the Inn-Danube (Mulheim-Obernberg, Passau-Ingling and Engelhartszell-Jochenstein), each on the border between two countries. We analysed land use patterns within a 500 m wide buffer area along the main channel using photo-interpretation and compared the situations between the 1950s, 1980’s and 2010’s. Temporal changes were assessed with transition matrices and selected spatial metrics, including fragmentation indices. Over this period, forest area remained similar at three sites, increased slightly at two sites and decreased at one site. However, on average, 12.5% of floodplain forest had changed location (range: 7.3% (Engelhartszell-Jochenstein)– 26.5% (Kembs-Efringen-Kirchen)). The natural development of unmanaged areas and agricultural abandonment after World War II has led to the emergence of young riparian forests along rivers. In the Upper Rhine region, the results showed asymmetry in these two factors, with unmanaged natural areas most important on the French side and agricultural abandonment on the German side. Along the Inn-Danube, agricultural abandonment has led to an increase or stagnation of floodplain forest areas. In most cases, development of transport infrastructure between the 1950s and 2010s has caused fragmentation of the forest area, reducing the relict forest to a patchy green corridor with reduced functionality and interfacing. To go further and improve the management of these relict forests, we have to investigate the interdependency between practices related to infrastructure operation and the role that biodiversity plays for stakeholders.

New record of Collembola (Hexapoda) from the Prutul de Jos scientific reserve

The paper presents new data about the species diversity of the order Collembola from the Prutul de Jos Scientific Reserve. A total of 13 species of Collembola from 11 genera and 5 families were identified for the first time in the floodplain forest of the Prutul de Jos Scientific Reserve. Among the identified collembolan species one - Endonura lusatica Dunger, 1966 is new for the fauna of the Republic of Moldova.