Development and validation of integrated pest management modules against spotted pod borer Maruca vitrata Fabricius on garden bean Lablab purpureus var. typicus (L.)

To reduce the detrimental effect of insecticides, an effective Integrated Pest Management (IPM) module is necessary for the eco-friendly management of Maruca vitrata in garden bean ecosystem. Two field trials were carried out to evaluate the efficacy of different insecticides and botanicals against M. vitrata on Lablab purpureus var. typicus. Two seasons field evaluation of insecticides revealed that chlorantraniliprole 18.5 SC  was the most effective treatment to control the pest recorded 0.11 and 0.36 larva/plant in two seasons, respectively after two rounds of spray followed by flubendiamide 20 WG (0.46 and 0.92 larva/ plant) and emamectin benzoate 5 SG (0.50 and 0.95 larva/plant). Among botanicals tested, commercial neem formulation and 5% Ageratina adenophora recorded the least larval count of 1.64 & 1.05 larva/plant and 2.24 & 1.45 larva/plant in two seasons, respectively. IPM modules were developed with three effective insecticides (chlorantraniliprole 18.5 SC, flubendiamide 20 WG and emamectin benzoate 5 SG), two effective botanicals (commercial neem formulation 1500 ppm and 5% A. adenophora) along with the pheromone trap for validation. All the IPM modules were equally effective in managing M. vitrata population on L. purpureus and recorded a significantly (at 5 %) lower larval population than the farmer’s practice. The residues of chlorantraniliprole, flubendiamide and emamectin benzoate reached below the detectable level at the time of harvest. The population reduction of predatory coccinellids and spiders was also lower in IPM modules than in farmer’s practice. An increased benefit cost (1.95 to 1.99) ratio was observed in IPM modules. 

Degree days and demography of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on maize at different temperatures

The temperature has a direct effect on the activity of insect pests and their developmental rate. The increasing temperature could profoundly influence the population dynamics, life cycle, length of reproduction, fecundity, and longevity. In the present study, the impact of different temperatures (32, 33, 34, 35 and 36°C) on the degree days and population fitness of Spodoptera frugiperda (J. E. Smith) was evaluated under artificial conditions. The results showed that for S. frugiperda, an average of 690.38 degree days was required to complete the total life span. The total larval developmental time, pupal duration and adult longevity required 237.38, 184.47 and 228.10 degree days, respectively. The life history data of S. frugiperda were analysed by using TWOSEX-MSChart. An increase in temperature reduced the developmental time of S. frugiperda at age x and stage j. The highest reproductive value (vx) of S. frugiperda was obtained at 34°C (600 individuals per day) and was found to be reduced at a further increase in temperature of 35°C (260 individuals per day) and 36°C (120 individuals per day). These results signify the improved fitness of S. frugiperda with increasing temperature levels, and the degree days help to predict the development pattern of S. frugiperda based on heat accumulation

Solanum melongena leaf extract based zinc oxide nanoparticles synthesis using green chemistry concepts

1273-1277Nanoparticles of zinc oxide (ZnO NPs) have been synthesised from naturally available Eggplant, Solanum melongena leaf extract. The methodology has been optimized to obtain ZnO NPs which as are characterized using UV-Visible, X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and FT-Infra red (FTIR) tools to confirm their nano dimensions and chemical properties. The SPR band is obtained at 389 nm in UV-visible absorption spectrum confirmes the formation of ZnO NPs while the presence of -OH, -C-O, -CH2 and –COO groups at vibrational frequencies of 3500, 105, 3000 and 1640 cm-1, respectively are observed from FTIR. Further, the SEM images show regular flakes like structure, and the average distribution of the nanoparticle is found to be around 100 nm. The newly synthesised ZnO NPs using leaf extract of Solanum melongena show considerable activity against both Gram-negative and Gram-positive bacteria. The ZnO NPs is proved to be more potent against Staphylococcus aureus than E. coli

2-Bromo-4-tert-butyl-6-[(pyridin-2-yl­imino)­meth­yl]phenol

In the title compound, C16H17BrN2O, the pyridine and benzene rings are almost coplanar [dihedral angle = 1.3 (2)°]. An intra­molecular O—H⋯Br inter­action forms an S(5) ring motif

Solanum melongena leaf extract based zinc oxide nanoparticles synthesis using green chemistry concepts

Nanoparticles of zinc oxide (ZnO NPs) have been synthesised from naturally available Eggplant, Solanum melongena leaf extract. The methodology has been optimized to obtain ZnO NPs which as are characterized using UV-Visible, X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and FT-Infra red (FTIR) tools to confirm their nano dimensions and chemical properties. The SPR band is obtained at 389 nm in UV-visible absorption spectrum confirmes the formation of ZnO NPs while the presence of -OH, -C-O, -CH2 and –COO groups at vibrational frequencies of 3500, 105, 3000 and 1640 cm-1, respectively are observed from FTIR. Further, the SEM images show regular flakes like structure, and the average distribution of the nanoparticle is found to be around 100 nm. The newly synthesised ZnO NPs using leaf extract of Solanum melongena show considerable activity against both Gram-negative and Gram-positive bacteria. The ZnO NPs is proved to be more potent against Staphylococcus aureus than E. coli

The Pore-Forming Protein Cry5B Elicits the Pathogenicity of Bacillus sp. against Caenorhabditis elegans

The soil bacterium Bacillus thuringiensis is a pathogen of insects and nematodes and is very closely related to, if not the same species as, Bacillus cereus and Bacillus anthracis. The defining characteristic of B. thuringiensis that sets it apart from B. cereus and B. anthracis is the production of crystal (Cry) proteins, which are pore-forming toxins or pore-forming proteins (PFPs). Although it is known that PFPs are important virulence factors since their elimination results in reduced virulence of many pathogenic bacteria, the functions by which PFPs promote virulence are incompletely understood. Here we study the effect of Cry proteins in B. thuringiensis pathogenesis of the nematode Caenorhabditis elegans. We find that whereas B. thuringiensis on its own is not able to infect C. elegans, the addition of the PFP Cry protein, Cry5B, results in a robust lethal infection that consumes the nematode host in 1–2 days, leading to a “Bob” or bag-of-bacteria phenotype. Unlike other infections of C. elegans characterized to date, the infection by B. thuringiensis shows dose-dependency based on bacterial inoculum size and based on PFP concentration. Although the infection process takes 1–2 days, the PFP-instigated infection process is irreversibly established within 15 minutes of initial exposure. Remarkably, treatment of C. elegans with Cry5B PFP is able to instigate many other Bacillus species, including B. anthracis and even “non-pathogenic” Bacillus subtilis, to become lethal and infectious agents to C. elegans. Co-culturing of Cry5B-expressing B. thuringiensis with B. anthracis can result in lethal infection of C. elegans by B. anthracis. Our data demonstrate that one potential property of PFPs is to sensitize the host to bacterial infection and further that C. elegans and probably other roundworms can be common hosts for B. cereus-group bacteria, findings with important ecological and research implications

A Multi-Data Geospatial Approach for Understanding Flood Risk in the Coastal Plains of Tamil Nadu, India

The coastal plains of Tamil Nadu, India, are prone to floods, the most common disaster experienced in this region almost every year. This research aims to identify flood risks in the coastal plain region of Tamil Nadu, delineated through a watershed approach with 5020 micro-administrative units covering an area of about 26,000 sq. km. A comprehensive flood risk assessment covering hazard, vulnerability, and exposure parameters was carried out using multiple datasets derived from field surveys, satellite data, and secondary data sources. The flood hazard layer was prepared on a probability scale (0−1) with the help of Sentinel-1 Synthetic Aperture Radar data coupled with GIS-based water rise modelling using Shuttle Radar Topography Mission Digital Elevation Model (SRTM-DEM) and reports of the District Disaster Management Plans of 13 coastal districts. In addition, the National Resources Conservation Service-Curve Number (NRCS-CN) method was adopted to estimate surface runoff potential for identifying low probability flood-prone regions. The vulnerability and exposure of the population to flood hazards were determined using census and household data-based indicators. The different categories of built-up areas were delineated and intersected with the flood hazard layer to estimate elements at flood risk. An exhaustive field survey was conducted at 514 locations of the study area, targeting deprived communities of all major settlements to validate the flood hazard layer and understand the public perceptions. The amalgamation of results shows that very high flood risk prevails in the northern parts of coastal Tamil Nadu, especially the stretch between Chennai and Cuddalore. In addition, to provide baseline datasets for the first time at micro-administrative units for the entire coastal plains of Tamil Nadu, the study offers a pragmatic methodology for determining location-specific flood risks for policy interventions