13 research outputs found
Efficacy of Metarhizium rileyi and Beauveria bassiana as Biocontrol Agents against Third-Instar Spodoptera frugiperda under Laboratory Conditions
No full textManaging the Fall Armyworm, Spodoptera frugiperda (J. E. Smith), a significant pest affecting maize, has become challenging due to widespread restrictions on synthetic pesticide use and the emergence of insecticide-resistant populations. As a sustainable alternative, entomopathogenic fungi have shown promise as biological control agents against S. frugiperda. In this study, commercial formulations of two fungal biocontrol agents, Metarhizium rileyi (Mr-18 strain) and Beauveria bassiana (Bb-52 strain), were assessed against third-instar larvae of S. frugiperda under laboratory conditions. Results showed that both M. rileyi and B. bassiana were similarly effective, with M. rileyi exhibiting a slightly lower LC50 value (1.648 x 10⁵ ppm) compared to B. bassiana (2.203 x 10⁵ ppm), particularly in populations from Telangana. These results highlight the potential of using effective strains of B. bassiana and M. rileyi at a concentration of 1 x 10⁵ conidia/ml as viable biocontrol strategies against S. frugiperda
Helicoverpa armigera (Hubner) Associated Cross Resistance Patterns in South Indian Crop Ecosystem
No full textAim: To study the cross resistance patterns associated with Mahaboobnagar, Raichur, Nagpur populations of Helicoverpa armigera (Hubner).
Study design: Bioassay
Place and Duration of Study: The experiment was carried out from February 2010 to May 2011 at Department of Entomology, College of Agriculture, Rajendranagar, Hyderabad, Telangana.
Methodology: Helicoverpa armigera was selected for indoxacarb in F1 and F2 continuously then the population subjected to different selected insecticides to know the cross resistance patterns associated.
Results: Mahaboobnagar population recorded 1.109 and 0.816 fold resistance at LD50 and LD90, respectively, while Raichur population has developed still higher levels of relative resistance by 1.591 and 0.846 fold when compared with the Nagpur population at LD50 and LD90, respectively. Similarly, the Raichur population has developed 1.435 and 1.037 folds relative resistance at LD50 and LD90, respectively as compared with the Mahaboobnagar population.
The Mahaboobnagar population resistant to indoxacarb at F3, when subjected to selected insecticides like cypermethrin, methomyl, spinosad showed a negative cross resistance ratio of 0.665, 0.830, 0.916 to cypermethrin, methomyl, spinosad respectively, and a positive cross resistance ratio of 1.019 to indoxacarb, while similar trend was displayed by Raichur population showing a negative cross resistance ratio of 0.932, 0.565, 0.803 to cypermethrin, methomyl, spinosad respectively and positive cross resistance of 1.036 indoxacarb further, same trend was shown by Nagpur population by displaying a negative cross resistance ratio of 0.610, 0.735, 0.519 to cypermethrin, methomyl, spinosad and positive cross resistance ratio of 1.026 to indoxacarb.
Conclusion: Continuous application of single insecticide belonging to a specific group across the generations increases the resistance from F1 to F3. Alternating the new chemistries with old conventional chemicals resulted in no cross resistance development as it was observed in all test populations
Relative Resistance of Different Insecticides on Chilli Thrips, Scirtothrips dorsalis (Hood) in Andhra Pradesh
No full textThe thrips population from Guntur district on chillies has developed high degree of resistance to various insecticides viz., monocrotophos, acephate, dimethoate, phosalone, carbaryl and triazophos followed by the population of Vizianagaram district with low levels of resistance implicating selection pressure and consequent resistance levels. The S. dorsalis population of Guntur district acquired resistance to the tune of 4.19 folds to monocrotophos, 5.62 folds to acephate, 5.59 folds to dimethoate, 6.80 folds to phosalone, 4.06 folds to carbaryl and 3.39 folds to triazophos at LC50 in comparison with the Vizianagaram district population
Cross Resistance Patterns Associated with Spinosad Resistant Helicoverpa armigera (Hubner) in South India
No full textAim: To study the cross resistance patterns associated with Helicoverpa armigera (Hubner) in south India.
Study Design: Bioassay.
Place and Duration of Study: The experiment was carried out in the Department of Entomology, College of Agriculture, Rajendranagar, Hyderabad,Telangana from February 2010 to May 2011.
Methodology: Spinosad resistant Helicoverpa armigera population in F1 and F2 subjected to different insecticides to know the cross resistance patterns associated.
Results: American bollworm population of Mahaboobnagar has developed 0.308 and 0.646 folds and 0.284 and 0.624 folds in Raichur population as compared with the Nagpur baseline population at F1. Mahaboobnagar population displayed a negative cross resistance ratio of 0.677 fold to cypermethrin, 0.806 fold to methomyl, 0.935 fold to indoxacarb and positive cross resistance of 1.039 fold to spinosad, similar trend was followed in Raichur population with a negative cross resistance ratio of 0.918 fold to cypermethrin, 0.543 fold to methomyl, 0.642 fold to indoxacarb and 1.060 fold to spinosad. Further, the Nagpur population exihibited a similar trend with a negative cross resistance ratio of 0.604 fold to cypermethrin, 0.690 fold to methomyl, 0.570 fold to indoxacarb and positive cross resistance ratio of 1.077 fold to spinosad at F3.
Conclusion: The present study revealed that the continuous application of same insecticide across the generations increases the resistance from F1 to F3. Alternating the new chemistries with old conventional chemicals results in no cross resistance development as it was observed in all three populations studied
Population Dynamics of Fall Armyworm Spodoptera frugiperda (J.E. Smith) and its Natural Enemies Maize in India
No full textThe studies on seasonal incidence of Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) on Maize in India was carried out at Maize research centre Rajendranagar, Hyderabad, during Rabi 2022-23. The correlation studies revealed that the percent infestation of FAW was found to be negatively significant with maximum temperatures (-0.491*) and positively significant with morning relative humidity (0.565*). Correlation of natural enemies (coccinellids, spiders, earwigs) with weather parameters (Maximum temperature, Minimum temperature, Relative humidity during morning and evening) revealed that coccinellids, spiders and earwigs were found to be positively significant with maximum temperature and spiders found to be negatively significant with evening relative humidity. They were found to be non-significant with remaining parameters
A comparative study between CAN score and Ponderal Index in identifying nutritional status of the neonate
No full textIntroduction: Inadequate supply of nutrients to the fetus results in fetal malnutrition. As a result, the fetus fails to grow resulting in intrauterine growth restriction (IUGR). Though Small for Gestational Age (SGA) is used synonymously for IUGR but the later shows evidence of malnutrition. To detect fetal malnutrition various methods are being used currently. CAN is clinical method to detect the nutritional status through physical examination. Detection of fetal malnutrition by CAN score and comparing with other methods was the aim of this study. Materials and methods: This hospital based prospective study was carried on 200 neonates delivered in district government hospital, Koppal. Nutritional status assessment was done using CAN score and is compared with ponderal index and birth weight for gestational age. Results: Incidence of fetal malnutrition was 41.5% using CAN score. 10.5% small for gestational age neonates were well nourished and 7% appropriate for gestational age neonates were malnourished when detected through CAN score. 14% neonates showed malnutrition with PI<2.5 but when detected through CAN score it was 8%.Well-nourished neonates with PI>2.5 were 86% but after CAN score 33.5% showed malnutrition. 
Evaluation of Compatibility of Metarhizium rileyi (Farlow) Kepler (Hypocreales: Clavicipitaceae) with Novel Insecticidal Molecules
No full textThe compatibility of the entomopathogenic fungus Metarhizium rileyi (Hypocreales: Clavicipitaceae) with selected new generation insecticides was evaluated to support its integration in pest management programs. Eight insecticides Chlorantraniliprole 18.5 % SC, Flubendiamide 39.35 %SC, Emamectin benzoate 5 % SG, Spinosad 48 % SC, Indoxacarb 15 % SC, Profenophos 50 % EC, Diafenthiuron 50 % WP, and Spinetoram 11.7 % SC were tested at their recommended field concentrations. Fungal growth was assessed 14 days post-inoculation to determine the impact of each insecticide on M. rileyi viability. Significant variation in growth inhibition was observed among the treatments. Chlorantraniliprole 18.5 % SC exhibited the highest compatibility, causing only 24.01 % growth inhibition, whereas Indoxacarb 15 % SC recorded the highest inhibition at 68.91 %, indicating low compatibility. These findings highlight the potential for selective use of insecticides in conjunction with M. rileyi to enhance the sustainability of integrated pest management strategies
Correlation between placental morphometry and maternal BMI in IUGR among Telangana population
No full textIn newborns one of the major problems is fetal growth restriction or Intra Uterine Growth Restriction (IUGR) or morbidity and mortality. Objective of the study is to examine the correlation between the maternal BMI in IUGR and placental anthropometry. Materials and methods - Present study was conducted in OBG Department of SVS Medical College and hospital in September-2020-march-2021. Total 22 IUGR placental samples collected and compared with normal placenta and BMI correlated in both groups. Results - mean diameter of placenta in IUGR fetuses’ range is 10.66-14.44; weight of placenta is 410.60 grams; hemoglobin level is 9.60 grams in IUGR pregnant women; BMI is 21.86 kg/m2 and gestational age was 35.60 wks
Screening of Tropical Maize Inbred Lines by Artificial Infestation for Resistance against Invasive Fall Armyworm in India
No full textAim: This study was aimed to find resistance sources against FAW.
Study Design: Randomised Block Design.
Place and Duration of Study: The Present study was conducted at Maize Research Centre, Hyderabad with promising germplasm during Kharif-2021, Rabi-2021-22 and Kharif-2022.
Methodology: Field-collected FAW egg masses were reared using maize leaf- and stalk-based diet at 27 ± 1 °C, 60 ± 5% relative humidity and 12 h day length. The resulting neonates were used to infest the seedlings of 34 diverse tropical maize inbred genotypes.
Results: A total of 15 genotypes were found to have recorded a leaf damage score of less than 5 with the least score recorded in BML 2 (3.24), followed by BML 11 (3.34), BML 7(3.37), BML 5 (3.37), BML 8 (3.49), CM 201 (3.60), BML 32-2 (3.91), CM 132 (3.97), BML 10 (4.01), BML 6 (4.02), BML 13 (4.34), CM202 (4.34), CM 131 (4.68), BML 90 (4.82), BML 45 (4.95) and displayed moderate resistance.
Conclusion: Out of 34 inbred lines studied 15 were found to be moderately resistant to fall armyworm based on LIR and cob damage score under artificial infestation
Cypermethrin and Methomyl Resistance in Helicoverpa armigera (Hubner)
No full textThe H. armigera larvae of the Mahaboobnagar district recorded a LD50 of 29.125 µg larva-1 and 59.609 µg larva-1 at LD90 for cypermethrin. The LD50 and LD90 values of cypermethrin for Raichur population of H armigera was 32.481 and 38.172 µglarva-1, respectively. Toxicity of cypermethrin to Nagpur population of H. armigera showed that the LD50 and LD90 values were 20.069 and 54.708 µg larva-1, respectively, The chi-square test revealed that the population used in the study was homogenous (*p<0.05%). The H. armigera larvae of the Mahaboobnagar district recorded a LD50 of 3.651 µg larva-1 and 10.287 µg larva-1 at LD90 for methomyl. The LD50 and LD90 values of methomyl for Raichur population of H armigera was 3.630 and 10.417 µg larva-1, respectively, while Toxicity of methomyl to Nagpur population of H. armigera showed that the LD50 and LD90 values were 2.652 and 7.214 µg larva-1, respectively, when the chi-square test revealed that the population used in the study was homogenous (*p<0.05%). From, the results obtained we can conclude that the continuous application of same chemistries across the generations increases the resistance from F1 to F3. Alternating with the new chemistries results in no cross resistance development as it was observed in all the three populations
