Percent Mortality Research Articles

In vitro Acaricidal Effect of Jatropha curcas Methanol Extract on ‎Rhipicephalus (Boophilus) decoloratus larvae

Tick infestation is considered a major problem because ticks cause widespread nuisance and losses and vectors of disease-causing agents, resulting in economic losses in livestock production. The use of chemical agents is the main stay in tick-control though current research into viable plant extracts as alternatives are on the increase. This study evaluated the larvicidal effect of crude methanolic extract of Jatropha curcas seed oil extract on Rhipicephalus (Boophilus) decoloratusticks. Various concentrations of 6.25, 12.5, 25 and 50 mg/ml were prepared from a stock (100 mg/ml) solution of the sample; control using 1% tween 80 and standard acaricide; Amitraz (positive control) were used. The mortalities were observed at time intervals of 6, 12, 18, 24 and 48 hours. The experiment was performed in triplicate. The extract had an LC50 and LC90 of 2.88mg/ml and 6.76mg/ml respectively after 48h. Carbohydrates, cardiac glycosides, saponins, tannins, steroids, terpenes, alkaloids and flavonoids were detected as phytoconstituents, and the extract exhibited significant mean percentage mortality from the control across all the concentrations after 24h. The result confirms that J. curcas is a good alternative to be used as a larvicidal agent in the control of Rhipicephalus (Boophilus) decoloratus.

Preparation of Biopesticide Powder from Jicama (Pachyrhizus erosus) Leaf Extract to Eradicate Whitefly Pests (Bemisia tabaci G.) on Eggplant Plants (Solanum melongena L.)

The use of synthetic pesticides in Indonesia is increasingly widespread because they are considered effective in killing pests. However, synthetic pesticides leave residues that can cause environmental pollution and human health problems. Therefore, another alternative is needed, namely switching to using environmentally friendly vegetable pesticides. One of the alternatives is biopesticide powder from jicama leaf extract as a whitefly pest controller. Pomace leaves contain active compounds that are toxic to whitefly, namely rotenone which is a group of flavonoid compounds. The method of making this biopesticide powder consists of 2 stages, the first is the preparation of jicama leaf extract through a maceration process for 2 days with the ratio of leaf powder and solvent, namely 40 g, 60 g, 80, and 100 g of jicama leaf powder in 500 ml of 96% ethanol. The second stage is the processing of jicama leaf extract into biopesticide powder through the encapsulation process, namely mixing the extract with maltodextrin using a weight ratio of extract maltodextrin, namely 1 : 2 (w : w). The analysis carried out was the test of biopesticide effectiveness against whitefly. After testing, it was found that the biopesticide powder that was effective in eradicating whitefly pests was a biopesticide powder with a ratio of 100 grams of jicama leaf powder in 500 mL of 96% ethanol with a dissolution dose of 20 g/L in water, which was able to kill whitefly with a mortality percentage of 100% on day 3.

Effect of the Essential Oil of Zanthoxylum Armatum DC. (Rutaceae) Against Aphid (Aphis Citricidus)

Aphids have been considered as a major pest of cultivated crops and invade a wide range of vegetables, cereals, and fruits. Use of synthetic chemical insecticides are the common aphid management practices in the world. The use of chemical insecticides/pesticides raises many concerns associated with the environment, biodiversity and human health. Therefore, the use of natural products such as essential oils have been tested extensively to assess their insecticidal and repellent activity. In this study different concentrations (0.1%, 0.2%, 0.3%, 0.4% and 0.5%) of essential oil (EO) from seeds of Zanthoxylum armatum were tested for their insecticidal and repellent activity for aphids using direct toxicity and repellency method. Results revealed that mortality and repellency were concentrations and exposure time dependent. Mean mortality percentage increased with the increasing concentration and exposure time. 100% mortality was observed in 0.5% concentration after 48 hrs exposure time. However, repellent activity increases with the increasing concentration and decreases with the increasing exposure time. The maximum repellence percentage (96.29%) was achieved in 0.5% oil concentration after 24 hrs of exposure time. Gas Chromatography - Mass Spectrometry (GC-MS) analysis of the essential oil revealed the presence of three major compounds such as Eucalyptol (46.47%), Methyl Cis-Cinnamate (11.13%), and D-Limonene (7.10%) reported as insecticidal activity. SAARC J. Agric., 21(2): 183-194 (2023)

Larvicidal potential of silver nanoparticles synthesized from Ocimum gratissimum leaf extracts against anopheles’ mosquito

Despite recent improvements in the methods used to eradicate and minimize mosquito populations, they still pose severe threats to human health. This study aimed to investigate the Larvicidal potentials of silver nanoparticles of Ocimum gratissimum on wild Anopheles larvae from Lagos. The plant used in this study was collected from the southeastern part of Nigeria, Ibite-Olo in Ezeagu Local Government Area of Enugu State. Wild Anopheles mosquito larvae were collected from a field at Kosofe Local Government Area of Lagos State, Nigeria where resistant Anopheline populations have been reported in and around Lagos State were brought to the laboratory and kept under standard insectary conditions (25–29 ℃;78–82% relative humidity). Aqueous extract of Ocimum gratissimum was made and subsequently into the silver nanoparticles. A bioassay test was performed according to WHO guidelines, with six different concentrations to assess the larvicidal activity and values obtained were subjected to log prohibit regression analysis to obtain LC50 and values with 95% confidence limit. The results of the larvicidal activities of the silver nanoparticles of Ocimum gratissimum showed that the mortality rate was dose-dependent with the percentage mortality increasing at a direct proportional rate as with dose and time of exposure. Ocimum gratissimum gave LC50 at 0.5 ppm and LC95 at 2.5 ppm respectively. The biosynthesized silver nanoparticles augmented the larvicidal activity of the silver nanoparticles of Ocimum gratissimum on wild Anopheles larvae from Lagos. Therefore, this study showed that the silver nanoparticles of Ocimum gratissimum have the potency to be used against an insecticide-resistant mosquito vector and are a suitable candidate for the development of novel natural insecticides.

Application of GIS and spatiotemporal analyses in viral infection modelling using multiple datasets – A case study on the SARS-CoV-2 epidemic

Introduction/objectiveViral and infectious diseases such as COVID-19 continue to pose a significant public health threat. In order to create an early warning system for new pandemics or emerging versions of the virus, it is imperative to study its epidemiology. In this study, we created a geospatial model to predict the weekly contagion and lethality rates of COVID-19 in Ireland. MethodsMore than forty parameters including atmospheric pollutants, metrological variables, sociodemographic factors, and lockdown phases were introduced as input variables to the model. The significant parameters in predicting the number of new cases and the death toll were identified. QGIS software was employed to process input data, and a principal component regression (PCR) model was developed using the statistical add-on XLSTAT. Results and conclusionsThe developed models were able to predict more than half of the variations in contagion and lethality rates. This indicates that the proposed model can serve to help prediction systems for the identification of future high-risk conditions. Nevertheless, there are additional parameters that could be included in future models, such as the number of deaths in care homes, the percentage of contagion and mortality among health workers, and the degree of compliance with social distancing.

PHYTOCHEMICAL SCREENING, ANTIBACTERIAL AND INSECTICIDAL ACTIVITIES OF STEM BARK EXTRACTS OF BOSWELLIA DALZIELII HUTCHIN FROM KALTUNGO, NIGERIA

The importance of traditional herbal medicinal system has now gained attention in developed and developing countries. Boswellia dalzielii is a tree grows in the wild usually in the Savannah region of West Africa. These work assessed the phytochemical constituents, antibacterial and insecticidal activities of the stem bark extracts of Boswellia dalzielii. The plant extracts were obtained using soxhlet method with petroleum ether, ethyl acetate, acetone, ethanol and water as solvents for 10 hours while the phytochemicals and insecticidal activities were determined using standard methods. The phytochemical screening showed significant presence of carbohydrate in the ethanol and water extracts while significant amount of tannin was detected only in the ethanol extract. The petroleum ether and ethyl acetate showed absence of carbohydrate, tannins, phlobotannin, cyanogenic glycoside, chlorogenic acid and alkaloid. Significant amount of flavonoid was seen in the water extract, while only the ethanolic extract showed significant amount of cardiac glycoside and alkaloid. The acetone extract showed significant quantity of alkaloid and terpenes and steroids. The antibacterial screening showed that ethanol extract had the highest inhibitory activity. The petroleum ether extract had the least active components with no activity on the test organisms. The insecticidal activity of the plant extracts showed that acetone extract had the highest insecticidal activity on both the test insects. Camponotus consobrinus shows the highest percentage mortality of 75% at a concentration of 500µg and LC50 of 1.64x102µg followed by the Acanthscelides obtectus with the percentage mortality of 53% at a concentration of 250µg and...

Evaluation of Plant Essential Oils against Sitophilus oryzae Linnaeus (Coleoptera: Curculionidae) under Laboratory Conditions

Sitophilus oryzae Linnaeus, commonly known as rice weevil is a globally serious pest of stored grains, especially rice. Considering the target specific nature of botanicals and less hazardous effect than synthetic insecticides, the study was conducted to evaluate the effectiveness and appropriate dosage of four essential oils i.e., lemongrass (Cymbopogon citratus Stap.), eucalyptus (Eucalyptus globulus Labill.), peppermint (Mentha piperita L.), and tea tree (Melaleuca alternifolia L.) against S. oryzae. Each essential oil was used at 0.1, 0.5, and 1.0 ml doses on filter paper. A long glass cylinder (1000 ml size), divided into three (A, B, and C) sections, supplied with 20 g rice at ends, was used in the study. Ten freshly emerged adults of S. oryzae were released in the center of B, whereas treated and untreated filter paper was placed at A and C section, respectively. Observations on repellency and mortality percentage were recorded after 24 and 48 hours of exposure. The results indicated that all the tested essential oils exhibited insecticidal potential against S. oryzae. The insecticidal activity of all the essential oils increased with their application dose and exposure timing. Maximum mortality of S. oryzae after 48 hours was recorded in tea tree (76.67±3.33%) at 1.0 ml dose, whereas maximum repellency was recorded with 0.1 ml lemongrass (76.67±12.02%) treatment. Overall, tea tree and lemongrass showed maximum insecticidal performance, whereas peppermint was the least effective. After 48 hours, the lowest [0.008 ml (0.001-0.019) and highest [0.018 ml (0.000-0.078) LD50 values against S. oryzae were recorded with lemongrass and peppermint essential oils, respectively. The LD50 values recorded for eucalyptus and tea tree treatment were 0.07 ml (0.000-0.059) and 0.009 ml (0.000-0.046), respectively. Therefore, it is suggested that the essential oils of either tea tree or lemongrass may be applied in the warehouses against S. oryzae, that may not only cause repellency but also mortality among them.

Microwave assisted disinfestation of green gram (Vigna radiata L.) infested with pulse beetle, Callasobruchus maculatus (F.).

Pulse beetle (Callasobruchus maculatus) is a common infestation during storage of legumes in India, and presently being managed by chemical fumigation. In the present investigation, a non-chemical method based on dielectric heating by microwaves (900W, 2450MHz) was studied for disinfestation of green gram at different grain layer thickness (5, 10, 15 and 20mm) and exposure durations (0-60s). The susceptibility (LT95) of different stages was in the order of egg (31.668s) > grub (40.388s) > pupa (44.176s) > adult (49.018s). The adult was tolerant up to 50s (R2-0.799, P < 0.01) to microwave exposure duration without green gram, and up to 30s (R2-0.804, P < 0.01) with green gram. Hundred percent mortality was observed at 10mm (30s, R2-0.969, P < 0.01) and 15mm (30s, R2-0.972, P < 0.01) grain layer thickness without significantly affecting grain quality. Cooking time and germination did not vary significantly up to 30s of exposure, thereafter, reduced significantly. However, water uptake did not vary significantly up to 60s of exposure. The microwave radiations are found effective for disinfestations of green gram without significantly affecting the grain quality.

Callosobruchus maculatus males and females respond differently to grandparental effects.

In this study, we used the cowpea weevil Callosobruchus maculatus (Coleoptera: Chrysomelidae) and two essential oils (mint and rosemary) to investigate the effect of the parents (F0) exposure to a sublethal dose of essential oil on grand offspring (F2) encountering the same essential oil. Then we evaluated biological parameters, including immature development time, sex ratio, adult emergence, egg number, egg hatch, longevity, and mating behaviors in three generations (F0, F1, and F2). Results showed when F0 experienced essential oil in the embryonic stage, parental and grandparental effects were more severe than adulthood experiences. Also, grandparental effects increased or decreased reactions of F2 generation when faced with a similar essential oil, depending on grand offspring sex. For example, when grandparents experienced rosemary essential oil in the embryonic stage, they produced more tolerant female grand offspring with a better ability to cope with the same essential oil (increased adult longevity and egg number). However, male grandoffspring were more sensitive (had a higher mortality percentage and less copulation success). Grandparental effects of exposure to mint essential oil diminished female grand offspring longevity and improved male copulation behavior parameters such as increased copulation duration and decreased rejection by females. In all, grandparental effects were different in male and female grand offspring based on the essential oil type experienced by F0.

Efficacy of Different Essential Oils Against Nymphal Stage of Aphid (Aphis craccivora Koch) in Green Gram (Vigna radiata L.)

Aims: Study the mortality rate of aphid, Aphis craccivora Koch when treated with different essential oils against the nymphal stage.&#x0D; Study Design: Complete randomized design.&#x0D; Place and Duration of Study: Biswanath College of Agriculture, Biswanath Chariali during 2022-23&#x0D; Methodology: All essential oils were applied at three different concentrations viz., 1%,3% and 5% and recorded the mortality percentage after 4,12, 24, 48 and 72 hours of application.&#x0D; Results: The result showed that neem oil had the best effect on the mortality of nymph (96.67%,100%,100%) in 1,3 and 5 per cent concentration after 72 hours after treatment. The second highest mortality was recorded against nymphs in mint oil (83.33%) followed by clove (80.00%), garlic (76.67%), ginger (73.33%) and eucalyptus (66.67%) oil against nymphs at 72 hours after treatment.&#x0D; Conclusion: In the present study essential oils showed that mortality rate increased with increasing concentration and times.

Overexpress miR-132 in the Brain Parenchyma by a Non-invasive Way Improves Tissue Repairment and Releases Memory Impairment After Traumatic Brain Injury.

Traumatic brain injury (TBI) is a serious public health problem worldwide, which could lead to an extremely high percentage of mortality and disability. Current treatment strategies mainly concentrate on neuronal protection and reconstruction, among them, exogenous neural stem cell (NSC) transplantation has long been regarded as the most effective curative treatment. However, due to secondary trauma, transplant rejection, and increased incidence of brain malignant tumor, a non-invasive therapy that enhanced endogenous neurogenesis was more suitable for TBI treatment. Our previous work has shown that miR-132 overexpression could improve neuronal differentiation of NSCs in vitro and in vivo. So, we engineered a new kind of AAV vector named AAV-PHP.eB which can transfect brain parenchyma through intravenous injection to overexpress miR-132 in brain after TBI. We found that miR-132 overexpression could reduce impact volume, promote neurogenesis in the dentate gyrus (DG), accelerate neuroblast migrating into the impact cortex, ameliorate microglia-mediated inflammatory reaction, and ultimately restore learning memory function. Our results revealed that AAV-PHP.eB-based miR-132 overexpression could improve endogenous tissue repairment and release clinical symptoms after traumatic brain injury. This work would provide a new therapeutic strategy for TBI treatment and other neurological disorders characterized by markable neuronal loss and memory impairment. miR-132 overexpression accelerates endogenous neurogenesis and releases TBI-induced tissue repairment and memory impairment. Controlled cortical impact onto the cortex would induce serious cortical injury and microglia accumulation in both cortex and hippocampus. Moreover, endogenous neuroblast could migrate around the injury core. miR-132 overexpression could accelerate neuroblast migration toward the injury core and decreased microglia accumulation in the ipsilateral cortex and hippocampus. miR-132 could be a suitable target on neuroprotective therapy after TBI.

Forecasting of neonatal mortality trend at a special new-born care unit in Odisha, India: A time-series analysis

New born mortality is a public health problem in the state of Odisha. Newborn mortality is a dynamic process and variations in mortality are observed temporally and seasonally, and also across health facilities. Prior knowledge of mortality burden can enable health system’s readiness in terms of resources allocation and timely intervention, thereby improving the chances of survival of sick newborns admitted in the hospitals. Hence, this study aimed to examine temporal trends of newborn mortality in a Special Newborn Care Unit of Saheed Laxman Nayak Medical College and Hospital (SLNMCH) in Odisha and forecast a short-term monthly projection.The Box-Jenkins approach was used to fit a seasonal autoregressive integrated moving average (SARIMA) model to the monthly recorded mortality among the hospitalized new borns in the SNCU during 2016-2020. The best-fit model for forecasting was found based on the Akaike Information Criterion.The time-series analysis revealed a modest upward trend in newborn mortality rate among SNCU admitted newborns, with peaks in the late winter and late summer months. The seasonal ARIMA (0,1,1)(1,1,1)12 model offered the best fit for time-series data. This model predicted the monthly percentage of mortality in SNCU admitted newborns in the range of 9% to 35% with respective 95% confidence interval for two years period (2021-2022).SARIMA models are useful for monitoring newborn mortality and provide an estimate of temporal trends and seasonality. The models are helpful for predicting occurrence of mortality in the SNCU of SLNMCH and could be useful for developing early warning systems. It may help in early detection, timely treatment, and prevention of serious complications in admitted sick newborns.

Biological and histological changes and DNA damage in Oreochromis niloticus exposed to oxytetracycline: a potential amelioratory role of ascorbic acid

Antibiotics are crucial in the control of bacterial infections on fish farms. However, the influence of licensed antibiotics on DNA damage, histological changes, and protein differentiation in some farmed fish species is unidentified. The current study aimed to investigate the effect of therapeutic (80 mg/kg body weight/day) and high doses (160 mg/kg body weight/day) of oxytetracycline (OTC) on some biological indices, protein differentiation, histological changes, and DNA damage in Oreochromis niloticus (n = 360; 40 ± 3.5 g) and the potential positive effects of dietary ascorbic acid (AA) and whether it is capable of reducing the deleterious impacts of OTC and working synergistically to increase fish disease resistance and decrease morbidity and mortality rates. In the current study, fish were fed diets with or without OTC (80 or 160 mg/kg body weight/day) and AA (100 mg/kg diet/day) for 28 days, followed by a bacterial stress test with two different virulent strains for 14 days. Treatments include CTR (control; without additives), AA, OTC80, OTC160, OTC80 + AA, and OTC160 + AA. The results revealed that the AA group had the best antioxidative (significant increase in SOD, CAT, and GPx) and immunomodulatory effects (an increase in IgM, nitroblue tetrazolium, and total leucocytic count). Furthermore, the hematological parameters, immune indices (NBT), and antioxidant enzymes were significantly reduced by OTC160 (p ≤ 0.05). The results also showed that OTC160 notably augmented the activity of liver (ALT, AST, and LDH) and kidney (creatinine and urea) damage markers (p ≤ 0.05). OTC160 revealed considerable hepatic and renal tissue damage and significantly higher hepatocyte DNA damage. Pathological changes and DNA damage were directly correlated to the dosage of OTC exposure, where they were more severe in OTC160. OTC80 showed insignificant changes in most parameters. Compared to CTR, the inclusion of AA in the O. niloticus diet significantly restored the biological indices, histological changes, and DNA damage in OTC-treated groups. The morbidity and mortality percentages after bacterial challenge were significantly lower in the OTC80 + AA group, followed by the OTC160 + AA group than in the CTR. These results corroborate the use of AA as a potent antioxidant and immune stimulant and a potential co-adjuvant to OTC in the diet of O. niloticus to reach optimal resistance to disease.

The efficiency of using integrated control agents to manage the Dubas bug Ommatissus binotatus lybicus De Berg (Homoptera: Tropiducidae) in Karbala Governorate

This study aims to rate the efficiency of using chemical pesticides, bio-fungicides, and the interaction between them against the nymphal and adult stages of the Dubas insect (Ommatissus binotatus lybicus De Berg). Anyhow, the laboratory and field results of the pesticides significantly affected the treated phases. The field results of the treatments were significantly increased after around two weeks, as for the average percentage of death in the treated nymphs. It reached 89.29-75.03-72.5-71, respectively. The results of the interaction treatments between fungal biocides (Beauveria bassiana, Paecilomyces sp, Beauveria bassiana, Metarhizium anisopliae, Metarhizium anisopliae, and Paecilomyces sp) were significantly increased after two weeks of treatment, as the average percentage of death of the treated nymphs reached 63.95 -77.19 -63.5, respectively. The laboratory results of the treatments were significant for the pesticides used after nine days of treatment, as the average percentage of death of the adults reached 86.01 - 39.25 -32.16 -36.81, respectively. Moreover, the interaction coefficients between the fungal biocides mentioned in the paragraph above were significant after nine days of treatment. The average percentage of treated adults' deaths reached 38.13 -39.64 37.57 - 86.02 to treat the interaction between the chemical pesticide Actara and B. bassiana. The chemical pesticide Actara excelled in the field experiment, as it gave the highest percentage of mortality when used at concentrations of 1-1.5 g/L after two weeks of treatment. The average percentage of nymphs killed was 89.29.&#x0D; As for the laboratory experiment results, the chemical pesticide Actara was also superior, as it gave the highest mortality rate for adult females. The average mortality rate for adult females reached 86.01 after nine days of treatment compared to the rest of the treatments using other pesticides.&#x0D;

Contributing factors, complications and immediate outcome of birth asphyxia in a tertiary care centre in Assam

: Birth asphyxia is defined by the World Health Organization as the failure to initiate and sustain breathing at birth. Etiological factors include maternal factors like hypertension, chorioamnionitis, diabetes, maternal pulmonary or cardiac disorders, placental factors like abnormal placentation, abruption, infarction, hydrops, uterine rupture, umbilical cord prolapse, entanglement, true knot, compression, abnormalities of blood vessels, fetal factors like anemia, cardiomyopathy, infections, hydrops, neonatal factors like cyanotic congenital heart disease, persistent pulmonary hypertension of the newborn, respiratory failure due to meconium aspiration syndrome, congenital pneumonia, pneumothorax etc.: To study the contributing factors, complications and immediate outcome of birth asphyxia in a tertiary care centre in Assam.: It was a prospective observational study carried out in NICU, Gauhati Medical College &amp; Hospital, Guwahati, Assam. The study included clinical profile of 200 cases of birth asphyxia admitted to the above center during period of one year starting from 1st of August 2021 to 31 July 2022.: In our study, out of 200 neonates, 102(51%) were male and 98(49%) were female. 161 cases (80.5%) were term.115 mothers (57.5% were primigravida and 85 mothers (42.5%) were multigravida. Various antenatal contributing factors were found to be meconium stained liquor (68%), anemia (57%), pregnancy induced hypertension (15%), prolonged labor (28.5%), fever(5%), antepartum haemorrhage (5.5%), chorioamnionitis (5%).Various complications of birth asphyxia observed in the study were hyperbilirubinemia 76 cases (38%), hypocalcemia 46 cases (23%), shock 31 cases (15.5%), DIC(13%), meconium aspiration syndrome 24 cases (12%), hypoglycemia 15 cases(7.5%),sepsis 13 cases (6.5%), apnea 14 cases (7%), Necrotising Enterocolitis 6 cases (3%), AKI 120 cases (60%) and the total mortality percentage was 26%.: Birth asphyxia is a leading cause of mortality among the newborn. The contributing factors needs to be addressed at the earliest to decrease the mortality and morbidity due to birth asphyxia.

Investigation On the Larvicidal Potential of Endophytic Fungi Isolates from Psoralea corylifolia And Leptadenia reticulata Against Aedes Aegypti

Globally, several million peoples are infected with epidemic-prone mosquito-borne diseases like yellow fever and malaria that is transmitted to humans by the bites of infected mosquitoes. Psoralea corylifolia, often known as babchi, is a well-liked herb that has been utilised in traditional Ayurvedic and Chinese medicine for many years for its miraculous abilities to treat a variety of skin conditions and Leptadenia reticulata, also known as Jivanti is an herb that is traditionally used in treating the conditions like malaria, diabetes, and liver disorders. The present study investigated the larvicidal properties of endophytic fungi isolated from Psoralea corylifolia and Leptadenia reticulata against Aedes aegypti. The highest larvicidal activity was seen in Trichodermata viride and Candida albicans species from leaves of L. reticulata was found to be 85.71% and 90.47 at 20 ppm. Likewise, Piriformospora indica and Aspergillus niger species from the leaves of P. corylifolia was found to be 66.66% and 83.33 % respectively. Candida albicans from leaves of L. reticulata and Aspergillus niger from the leaves of Psoralea corylifolia showed the highest mortality percentage was found to be 90.47 and 83.33 at 20 ppm respectively. The present study reveals the determination of optimal, eco-friendly, and selective mosquito larvicidal agents. The development of innovative and affordable medications to combat diseases spread by mosquitoes will be aided by more research on the isolation, characterisation, and determination of the mechanism of action against the selective mosquitos.

Comparative effectiveness of biorational pesticides for management of Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams & Granara de Willink in Gymnema sylvestre (Retz.) R.Br. ex Sm

The cotton mealybug, Phenacoccus solenopsis Tinsley and papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) are becoming major threats to the production of Gymnema sylvestre R. Br. (Asclepiadaceae) in India. Management mainly depends on chemical insecticides which cause a serious problem of pesticide residue and insecticide resistance. The use of biorational insecticides such as biopesticides, botanicals, insect growth regulators, and microbial insecticides is important components of an Integrated Pest Management (IPM) program for successful management. We evaluated the bio-efficacy of twelve biorational insecticides, including entomopathogenic fungi (EPF), using the leaf spray method in laboratory conditions at 25 ± 1 °C, 70 % ± 5 % RH. The results revealed that the highest percent mortality was recorded by acetamiprid 20 % SP (100.00 %), followed by azadirachtin (98.27 %), Lecanicillium muscarium (2 × 109 spores/mL) (85.70 %) and Ocimum sanctum leaf extract (76.87 %) at 120 h after treatment (HAT) in P. solenopsis. In P. marginatus, 100.00 %, 96.39 % and 85.67 % and 74.90 % mortalities were achieved by acetamiprid 20 % SP, azadirachtin, L. muscarium (2 × 109 spores/mL) and O. sanctum leaf extract, respectively, at 120 HAT during the first spray. Various biorational insecticides showed a more or less similar trend of percent mortality in both species during the second spray. In both species, the lowest percent mortality was recorded by Andrographis paniculata leaf extract (46.29, 44.54) and (41.03, 46.39) at 120 Hours after treatment in the first and second spray, respectively. It was concluded that all the prescribed treatments are more effective than the control. Overall, azadirachtin recorded the highest percent mortality after acetamiprid and had the shortest LT50 (12.52 h) and (13.87 h) values in P. solenopsis and P. marginatus, respectively. Our study emphasizes that biopesticides like Azadirachtin 1 % EC (10000 ppm), L. muscarium (2 × 109 spores/mL) (5 mL/L) and O. sanctum leaf extract (5 %) may be recommended as alternatives to synthetic insecticides. Botanicals and EPF would be the most effective approach for sustainable integrated management of P. solenopsis and P. marginatus in the G. sylvestre ecosystem.

IN VITRO ACUTE TOXICITY OF DANDELION LEAF EXTRACT (Taraxacum officinale F.H.Wigg) WITH BRINE SHRIMP LETHALITY TEST (BSLT) METHOD

Toxicity is a characteristic feature of substances that can cause harmful effects. This study aimed to determine the toxicity of dandelion leaves (Taraxacum officinale F.H. Wigg) to Artemia salina Leach larvae within 24 hours. Dandelion leaves were extracted using a maceration method with 50% ethanol. The yield was 5.88%. The results showed that dandelion leaves contain alkaloids, flavonoids, steroids, triterpenoids, and phenols. Toxicity tests were performed using the Brine Shrimp Lethality Test method, where the final result was the LC50 value. Artemia salina Leach larvae were divided into five groups. Each group had ten larvae that underwent three replications. The 50%ethanolic extract of dandelion leaf concentrations in the treatment media were 50 ppm (P1), 100 ppm (P2), 150 ppm (P3), 200 ppm (P4), and 0 ppm (seawater) as the control. Probit analysis of Artemia Salina Leach mortality percentage data. The results indicated that the 50%ethanolic extract of dandelion leaves is harmful to larvae, with LC50 values of 165,223 ppm (toxic) or in the equation y = 2,114x + 0,311, with an R² value of 0,9435. Keywords: Artemia salina, BSLT, Dandelion leaf, LC50, Toxicity

A Study of the Toxic Effect of Plant Extracts against Philaenus spumarius (Hemiptera: Aphrophoridae).

The meadow spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae) is distributed in several habitats worldwide and has been recently recognized as the main vector of Xylella fastidiosa subsp. pauca. This bacterium has been associated with olive quick decline syndrome (OQDS) in the Salento Peninsula (Italy) and is responsible for extensive desiccation and die-off of olive trees. Current OQDS management strategies include the control of P. spumarius populations, mainly through the removal of weed hosts and insecticide treatments. In addition to the mandatory phytosanitary measures, the demand for new strategies compatible with integrated pest management is increasing. In this study, laboratory biological assays were performed to assess the potential toxic effect of vegetal formulations against P. spumarius adults. Two formulations were tested at different concentrations: Form A, an emulsion of 10% hot pepper-infused oil (Capsicum annuum subspecies Cayenna in olive oil) and Arabic gum in an aqueous solution of extracts of Salvia guaranitica, and Form B, an aqueous solution of extracts of Taxus baccata. Both Form A and B showed to be toxic against P. spumarius compared to the water control. The mean percentage of spittlebug mortality obtained with Form A one hour after treatments was dose-dependent; the lethal dose values were 0.13% (LD25), 0.36% (LD50), and 0.85% (LD75). At the same time, no significant differences in mortality rate were observed between the 0.75% treatment and the treatments with deltamethrin (about 90%). The mean percentage of spittlebug mortality obtained with Form B ranged from 21% to 53% one hour after treatment, but these values were significantly lower than those obtained with deltamethrin. The effectiveness of Form A on the P. spumarius population was also evaluated in the field. The averages of captures in the three experimental blocks were 1.8/trap for treated and 7.7/trap for untreated plots, and the spittlebug populations significantly decreased after treatments. Based on these results and the literature data, we hypothesize that the effectiveness of Form A is the result of the synergistic effect of all its components. No symptoms of phytotoxicity were recorded on olive trees treated with Form A, and the number of P. spumarius specimens collected on these plants was much lower than on untreated plants. These results suggest the potential use of Form A in the protection of olive trees. This vegetal formulation can thus be considered as a valid alternative to chemical insecticides for the control of the main vector of X. fastidiosa and could be integrated into a sustainable management system for OQDS.

Regenerative strategies of Euterpe edulis (Arecaceae) at its altitudinal limits in the Atlantic Forest

AbstractPopulations occurring at the limit of a species' altitudinal distribution undergo strong environmental filtering. Rapid climate change intensifies this process, impacting ecological responses of populations. Understanding the effects of climate change, especially in the early stages of plant development, has become essential to predict vulnerability to extinction. However, few studies have explored initial establishment strategies of plant populations at the limit of their distribution in the face of global warming. We tested the effects of increasing temperatures on germination performance and on initial seedling establishment on two populations of Euterpe edulis, a palm tree widely distributed in the Atlantic Forest between 0 and 1400 m altitude. The tests were conducted in a laboratory, where the seeds were exposed to three conditions for 90 days: control at 25°C, and two treatments at higher temperatures (35 and 40°C). Germination percentage was not affected by population, seed size class or treatments. Average time for germination only increased in the Montane Forest population in the most extreme treatment, while in the sea level Restinga population, time for germination was affected by a small temperature increase. Mortality percentage in the Restinga population was similar in the post‐germination phase and in the temperature treatments. We concluded that E. edulis populations located at their lower altitudinal limit are closer to the species thermal limit, thus being more vulnerable to temperature increase than populations at the upper limit of the species' altitudinal distribution.