Next-Generation Sequencing on Insectivorous Bat Guano: An Accurate Tool to Identify Arthropod Viruses of Potential Agricultural Concern

Viruses belonging to the Dicistroviridae family have attracted a great deal of attention from scientists owing to their negative impact on agricultural economics, as well as their recent identification as potential aetiological agents of febrile illness in human patients. On the other hand, some Dicistroviruses are also studied for their potential biopesticide properties. To date, Dicistrovirus characterized in African mainland remain scarce. By using High-Throughput Sequencing technology on insectivorous bat faeces (Hipposideros Caffer) sampled in a cave used by humans to collect bat guano (bat manure) as fertilizer in Zimbabwe, we characterized the full-length sequences of three Dicistrovirus belonging to the Cripavirus and Aparavirus genus: Big Sioux River Virus-Like (BSRV-Like), Acute Bee Paralysis Virus (ABPV), and Aphid Lethal Paralysis Virus (ALPV). Phylogenetic analyses of ORF-1 and ORF-2 genes showed a complex evolutionary history between BSRV and close viruses, as well as for the Aparavirus genus. Herewith, we provide the first evidence of the presence of Dicistrovirus in Zimbabwe and highlight the need to further document the impact of such viruses on crops, as well as in beekeeping activities in Zimbabwe which represent a crucial source of income for Zimbabwean people.

Soil Erosion Spatial Prediction using Digital Soil Mapping and RUSLE methods for Big Sioux River Watershed

A recent conversion of the grasslands to cropland degrading the soil quality (SQ), and impacting the soil erosion and crop productivity in the West Corn Belt (WCB) of the USA. The current study was conducted to estimate the spatial distribution of soil erosion at Big Sioux River (BSR) watershed scale using the Geographical Information System (GIS)-enabled Revised Universal Soil Loss Equation (RUSLE). Spatial data such as weather, a digital elevation model (DEM), land use maps and soils were used for assessment of soil erosion was downloaded from the easily available online sources. Data showed that about 7% of grassland acreage reduced from 2008 (24%) to 2015 (17%), whereas, about 7.4% of cropland acreage increased from 2008 (64.6%) to 2015 (72%) in the BSR watershed. This grassland conversion to cropland increased the soil erosion (estimated using the RUSLE model) from 12.2 T ha−1 year−1 in 2008 to 14.8 T ha−1 year−1 in 2015. The present study concludes that grassland conversion to cropland in the BSR watershed increased the soil erosion, therefore, management practices essential to be applied to reduce the erosion risk and various other ecosystem services.

Metagenomic analysis of bat guano samples revealed the presence of viruses potentially carried by insects, among others by Apis mellifera in Hungary

The predominance of dietary viruses in bat guano samples had been described recently, suggesting a new opportunity to survey the prevalence and to detect new viruses of arthropods or even plant-infecting viruses circulating locally in the ecosystem. Here we describe the diversity of viruses belonging to the order Picornavirales in Hungarian insectivorous bat guano samples. The metagenomic analysis conducted on our samples has revealed the significant predominance of aphid lethal paralysis virus (ALPV) and Big Sioux River virus (BSRV) in Hungary for the first time. Phylogenetic analysis was used to clarify the relationship to previously identified ALPV strains infecting honey bees, showing that our strain possesses a close genetic relationship with the strains that have already been described as pathogenic to honey bees. Furthermore, studies have previously confirmed the ability of these viruses to replicate in adult honey bees; however, no signs related to these viruses have been revealed yet. With the identification of two recently described possibly honey bee infecting viruses for the first time in Hungary, our results might have importance for the health conditions of Hungarian honey bee colonies in the future.

Discovery of Known and Novel Viral Genomes in Soybean Aphid by Deep Sequencing

The phytobiome includes not just cellular microorganisms, but also all viruses associated with plants: the virome. Plants and aphids exchange viruses regularly and efficiently; thus, the plant virome is tightly linked with the aphid virome. Yet, little is known about aphid viromes, particularly that of the soybean aphid (Aphis glycines), one of the most economically important pest insects of soybean. To sample the soybean aphid virome, and to seek new viruses as potential biological control agents, we employed next-generation sequencing. Genomes isolated from viruses in soybean aphids collected at four sites revealed many viruses, and six complete or nearly complete genomes were assembled. Most abundant were the picornavirus-like dicistroviruses Aphid lethal paralysis virus and Rhopalosiphum padi virus. We also sequenced the genome of a new dicistrovirus, Big Sioux River virus, fragments of which had been found previously in honey bee. Genome sequences that represent two entirely new virus families were obtained. These include an abundant tetravirus-like virus and a virus distantly related to cileviruses of plants and negeviruses of insects. Surprisingly, Cotton leafroll dwarf virus, a member of the genus Polerovirus, was found in soybean aphids from China, suggesting that the soybean aphid may be a vector of this virus. This virus had not been reported previously in China or in soybean. This study provides a peek into the rapidly expanding, largely unexplored world of insect viromes that will provide valuable knowledge for future understanding of plant−virus−vector interactions. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .