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Not AvailableToxicological screening of Swietenia mahagoni Jacq. (Meliaceae, West Indies Mahogany) against the lepidopteran pest Spodoptera litura was examined. Phytochemical screening through GC-MS analysis revealed nine peaks with prominent peak area % in Bis (2-ethylhexyl) phthalate (31.5%) was observed. The larvae exposed to discriminating dosage of 100 ppm deliver significant mortality rate compare to other treatment concentrations. The lethal concentrations (LC50 and LC90) was observed at the dosage of 31.04 and 86.82 ppm respectively. Sub-lethal concentrations (30 ppm) showed higher larval and pupal durations. However, pupal weight and mean fecundity rate reduced significantly. Similarly, the adult longevity reduced significantly in dose dependent manner. Midgut histology studies showed that the methanolic extracts significantly disturbs the gut epithelial layer, lumen and brush border membrane compare to the control. The soil assay on a non-target beneficial organism, the soil indicator earthworm Eudrilus eugeniae, with extracts from S. mahagoni (200 mg/kg) showed no toxicity compared to Monocrotophos at the dosage of 10 ppm/kg. Current results suggest that this bio-rational plant product from S. mahagoni displays a significant effect to reduce lepidopteran pests with low toxicity to other beneficial species.Not Availabl

Effect of thiamethoxam on growth, biomass of rice varieties and its specialized herbivore, Scirpophaga incertulas Walker.

Not AvailablePesticides employed as seed treatment provides protection to seedlings against insect pests and diseases. Seed treatment of five rice varieties with thiamethoxam, an active ingredient of Actara 25 WG, showed positive effects on seed emergence, plant root and shoot biomass and reduction in dead heart damage under both controlled and greenhouse conditions. Under controlled condition thiamethoxam increased emergence in all of the rice varieties tested. The highest dose i.e., 2.0 g L−1of thiamethoxam had the maximum positive effects. The plant shoot and root characters were also influenced positively by the seed treatment. The total root length was superior with measurements of 38.6, 26.5 and 27.4 cm at 2.0 g L−1 concentration treatment for the rice varieties Ptb 33, AD09219 and AD07073 respectively. Similarly the root shoot ratio also increased positively at the prominent dosage for the varieties Ptb 33, AD07073 and AD09219 showing ratios of 0.402, 0.415 and 0.420 respectively. However, thiamethoxam seed treatment even at 0.50 g/L concentration showed significant difference over the untreated control in all the rice varieties tested. With respect to biomass (fresh and dry root and shoot weight) all the treatment doses of thiamethoxam was superior over the control in which the dose 2.0 g/L showed prominent fresh root and shoot weight in all the three tested varieties. Thus the thiamethoxam seed treatment except at the minimum dose showed increased shoot weight and root weight compared to untreated control. Considering the effect of thiamethoxam on insect pest, the spray application @ 0.2, 0.4, and 0.6 g/L of thiamethoxam 25WG significantly reduced the dead heart damage symptom caused by yellow stem borer in the all the varieties (TN1, Ptb33 and AD09219) tested compared to control treatment. Thus, the present investigation suggests that the bioactivator thiamethoxam when employed as a seed treatment plays a critical role in rice growth and development.Not Availabl

Response of Spodoptera litura Fab. (Lepidoptera: Noctuidae) larvae to Citrullus colocynthis L. (Cucurbitales: Cucurbitaceae) chemical constituents: Larval tolerance, food utilization and detoxifying enzyme activities

Not AvailablePest management has increased the alarm across researchers because of the possible risk from harmful insecticides dispersed in the natural environment. Plant derivatives are established from plant extracts and displays latent effects against damaging pests in a multiple ways. Citrullus colocynthis (L.) Schrad, largely dispersed across the world in the warm area. A purified, fractionated ethyl acetate extract of C.colocynthis (bitter apple) has shown 90% lethality toward Spodoptera litura third instar larvae, and slightly lower lethality to the fourth and fifth instars. Based on the food utilization, the mechanism of lethality appears to be reduced digestive enzyme activity. The enzyme analysis of S. litura against fraction F5 demonstrated that the level of ACP, ALP, ATP and LDH decreased significantly based on their concentration. The gut histology of S. litura shows disturbance in the midgut columnar cells against the fraction F5. The fraction F5 was further eluted using column chromatography and the subfraction A3 obtained and it was further characterized using FTIR and NMR. The subfraction A3 exhibits prominent mortality rate with 84% at 100 ppm concentration. The subfraction A3 was characterized and identified as stigmasterol.Not Availabl

Systematic induced resistance in Solanum lycopersicum (L.) against vascular wilt pathogen (Fusarium oxysporum f. sp. lycopersici) by Citrullus colocynthis and Trichoderma viride.

The antifungal effects of Citrullus colocynthis extract (Hexane, chloroform, methanol, and water) were tested in vitro on Fusarium oxysporum f. sp. lycopersici (Sacc.) W. C. Snyder & H. N. Hans (FOL), the causal agent of Fusarium wilt. Of these, methanol and water extract at 10% showed the highest inhibition of mycelial growth of FOL by 12.32 and 23.61 mm respectively. The antifungal compounds were identified through Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS). The methanol extract was compatible with the biocontrol agent Trichoderma viride. The antagonistic fungi were mass-cultured under laboratory conditions using sorghum seeds. Both T. viride and C. colocynthis methanol extract was also tested alone and together against FOL under both in vitro and in vivo conditions. The combination of T. viride and C. colocynthis showed the highest percentage of antifungal activity (82.92%) against FOL under in vitro conditions. This study revealed that induced systemic resistance (ISR) in enhancing the disease resistance in tomato plants against Fusarium wilt disease. The combined treatment of T. viride and C. colocynthis significantly reduced the disease incidence and index by 21.92 and 27.02% in greenhouse conditions, respectively. Further, the induction of defense enzymes, such as peroxidase (PO), polyphenol oxidase (PPO), β-1,3-glucanase, and chitinase were studied. The accumulation of defense enzyme was greater in plants treated with a combination of T. viride and C. colocynthis compared to the control. Reduction of wilt disease in tomato plants due to the involvement of defense-related enzymes is presumed through this experiment

Target and non-target response of Swietenia Mahagoni Jacq. chemical constituents against tobacco cutworm Spodoptera litura Fab. and earthworm, Eudrilus eugeniae

Not AvailableToxicological screening of Swietenia mahagoni Jacq. (Meliaceae, West Indies Mahogany) against the lepidopteran pest Spodoptera litura was examined. Phytochemical screening through GC-MS analysis revealed nine peaks with prominent peak area % in Bis (2-ethylhexyl) phthalate (31.5%) was observed. The larvae exposed to discriminating dosage of 100 ppm deliver significant mortality rate compare to other treatment concentrations. The lethal concentrations (LC50 and LC90) was observed at the dosage of 31.04 and 86.82 ppm respectively. Sub-lethal concentrations (30 ppm) showed higher larval and pupal durations. However, pupal weight and mean fecundity rate reduced significantly. Similarly, the adult longevity reduced significantly in dose dependent manner. Midgut histology studies showed that the methanolic extracts significantly disturbs the gut epithelial layer, lumen and brush border membrane compare to the control. The soil assay on a non-target beneficial organism, the soil indicator earthworm Eudrilus eugeniae, with extracts from S. mahagoni (200 mg/kg) showed no toxicity compared to Monocrotophos at the dosage of 10 ppm/kg. Current results suggest that this bio-rational plant product from S. mahagoni displays a significant effect to reduce lepidopteran pests with low toxicity to other beneficial species.Not Availabl

Challenges in rescuing snakes to protect human lives and promote snake conservation in Tamil Nadu, India

Background: Human-snake conflicts are common worldwide, often resulting in snakebites. Snakebite envenoming causes over 125,000 deaths and 400,000 permanent disabilities worldwide every year. India alone accounts for an average of ~58,000 annual snakebite-induced deaths. As human developments rapidly expand into suburban and rural areas, snakes are being displaced and incidences of residents finding snakes within their dwellings are increasing. Most people have an innate fear of snakes, compounded by centuries of negative influence from culture and mythology manifesting in people often attempting to kill snakes. Snake rescuers are volunteers who remove and relocate snakes to safe areas. This is a risky job that poses potentially fatal implications if bitten. These volunteers mostly receive no financial compensation for their time or transportation costs, but they choose to do it for their love of snakes, conservation, and for the altruistic nature of helping others. Snake rescuers often receive no formal training and are unfunded resulting in removing snakes improperly without adequate safety equipment or the required skill set to safely complete the task. Therefore, it is critical to determine their challenges and requirements to promote the safe rescue of snakes while protecting human lives. Methodology/principal findings: In this study, we developed an online questionnaire and interviewed 152 snake rescuers in Tamil Nadu, India following written informed consent to determine their challenges and needs for rescuing snakes safely. The results demonstrate that most rescuers are males, and they conduct snake rescues for varying lengths of time. They mostly receive no formal training and are bitten by snakes. They spend their own money on the purchase of snake-handling equipment and on treatments if bitten or injured during a rescue. Conclusions/significance: The rescuers highlighted the urgent need for formal training, safety equipment and standard protocols for rescuing snakes in Tamil Nadu. Overall, this study demonstrates that snake rescuing should be appropriately regulated by the authorities, in particular the Wildlife Division of State Forest Departments in India, and formal training along with necessary equipment, medical insurance and appropriate recognition should be provided to them to safely remove snakes from human dwellings and manage the safety of both snakes and humans. They can also act as educators to disseminate information about the preventive and first aid measures for snakebites as well as the ecological importance of snakes