Loading...
Theses
Browse
32 results
Search Results
ThesisItem Embargo MOLECULAR DIVERSITY, DISTRIBUTION, DEVELOPMENTAL BIOLOGY AND MANAGEMENT OF TOMATO LEAFMINER, Phthorimaea absoluta (MEYRICK) (LEPIDOPTERA: GELECHIIDAE)(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-11-14) PAVITHRA, H. B.; Dr. SHARANABASAPPA; Dr. KALLESHWARASWAMY. C MPhthorimaea absoluta (Meyrick), an invasive pest that causes considerable damage to tomato crop. Studies on population dynamics of P. absoluta in the farmers fields at Davanagere and Chikkamagaluru revealed that the highest pest incidence was recorded in the summer, followed by rabi and kharif season. The genetic diversity of P. absoluta samples from five districts of Karnataka was studied using mitochondrial gene, i.e., Cytochrome oxidase subunit I. The sequence comparison of the mtCOI gene of all the samples exhibited 95 to 100 per cent nucleotide similarity. Dendrogram results of CO1 region of P. absoluta samples revealed that there was not much diversity among P. absoluta population. Variation in biology of P. absoluta was observed when they were reared at five different temperatures in growth chambers. The duration of incubation period, larval and pupal period decreased as the temperature increased. The most conducive temperature for P. absoluta fecundity and per cent survival was found to be between 25 0C (136.73 eggs/female and 90.80 %) and 30 0C (141.59 eggs/female and 85.00 %). The median lethal concentrations of different insecticides among different P. absoluta populations from South India ranged from 1.40 to 106.0 ppm. Chlorantraniliprole showed more toxicity to second instar larvae, while the larvae were least susceptible to neonicotinoids. Evaluation of three modules viz., Bio-intensive IPM module, IPM module and Farmer’s practice module for the management of P. absoluta revealed significant variation in per cent leaf and fruit damage up to 75 days after transplanting (DAT) which may be due to impact of different treatment components in respective modules, but at 100 and 125 DAT, per cent leaf and fruit damage was on par among modules during rabi and summer seasons. IPM module was found to be superior by recording higher B:C ratio (3.85) followed by farmers practice (3.58).ThesisItem Embargo GENETIC DIVERSITY, STATUS OF INSECTICIDE RESISTANCE AND MANAGEMENT OF Leucinodes orbonalis GUENEE (LEPIDOPTERA: CRAMBIDAE) IN BRINJAL(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-12-12) SOMASHEKHAR V. GADDANAKERI; Dr. S. PRADEEP; Dr. B. S. NANDIHALLIInvestigations were carried out during 2020-22 to know the genetic diversity, field evolved resistance, enzymes governing insecticidal resistance and effect of various modules against brinjal shoot and fruit borer, Leucinodes orbonalis in brinjal. The genetic diversity of thirteen L. orbonalis populations was studied using Cytochrome oxidase subunit I (MtCO1). The highest genetic variation (0.033%) was found between the L. orbonalis of Dharwad and Bagalkot. Certain amino acids were either present or absent in different populations indicating their diversity. A detailed survey on insecticide usage pattern in brinjal across different locations of South India and Maharashtra revealed that eighteen insecticides were used by the farmers to manage L. orbonalis out of which chlorantraniliprole 18.5 % SC was highly preferred followed by emamectin benzoate 5% SG. The dose-mortality bioassays on field collected populations of L. orbonalis collected across South India and Maharashtra indicated varying levels of resistance development against emamectin benzoate (2.0 to 16.5-fold), chlorantraniliprole (1.7 to 9.7-fold), lambda-cyhalothrin (13.7 to 97.3-fold), indoxacarb (7.3 to 30.2-fold) and spinetoram (1.4 to 5.5-fold) as compared to laboratory reared susceptible population (F18). The biochemical assays revealed that enhanced detoxification of insecticides in field populations mainly occurred through upregulation of midgut metabolic enzymes viz., carboxylesterases (1.2 to 2.6-fold), glutathione S-transferases (1.8 to 5.8-fold), cytochrome P-450 (2.9 to 9.0-fold) and acetylcholinesterase (1.8 to 2.8-fold) as compared to susceptible population. Field experiments were carried out during Rabi 2020 and Kharif 2021 to assess the efficacy of various modules against L. orbonalis. The chemically intensive Farmer’s practice module recorded lower shoot (3.10%) and fruit infestation (12.08%) and was found superior by recording higher fruit yield (19.50 t/ha) with 2.84 B:C ratio followed by the adoptive IPM module (18.08 t/ha) with 2.77 B:C ratio.ThesisItem Embargo ISOLATION, CHARACTERIZATION AND EVALUATION OF FEMALE SEX PHEROMONE OF FALL ARMYWORM, Spodoptera frugiperda (J. E. SMITH) (LEPIDOPTERA: NOCTUIDAE)(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-12-12) SHARATH, K. N; SHARATH, K. N; Dr. SHARANABASAPPA; Dr. SHARANABASAPPA; Dr. BATHINI NAGENDRA BABU; Dr. BATHINI NAGENDRA BABUThe current investigation was carried out during 2020-22 at Department of Entomology, College of Agriculture, Shivamogga to study the geographical variation in sex pheromone composition, female calling behaviour and to evaluate the male moth response under field and laboratory conditions. The GC-MS analysis of the female sex pheromone gland extracts showed the presence of four pheromone compounds viz., (Z)-9-tetradecenyl acetate (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate and (Z)-11-hexadecenyl acetate. The relative proportion of these compounds varied significantly across different geographical populations and also elicited a strong antennal response in male moths when tested with GC-EAD. The male moths exhibited dose dependent response which further varied across different pheromone blends tested. The female calling behaviour varied across both geographical population and female calling age. Maharashtra population had the highest onset of calling time (120.75 minutes) and Telangana (69.05 min) and Gujarat (69.07 min) being the lowest did not show any significant variation in onset of calling between them. Similarly, the onset of calling was more in case of emergence day females (160.51 min) in all the four population and increased with age. Likewise, Gujarat population (229.75 min) called for longest duration and least calling duration was observed in case of Maharashtra population (200.25 min). Further, the proportion of calling and non-calling females varied significantly across progressive calling age. During field evaluation with commercial lures, a total of 415 moths were captured in four pheromone baited traps during the kharif season of 2021, the highest trap catches of males of S. frugiperda were seen during the July fourth week (27.75 moths/trap/week) and had a highly significant and positive correlation with larval infestation (r = 0.819**). The evaluation of different commercial sex pheromone lures to attract S. frugiperda showed a significant difference both among the treatments as well as across the different weeks of the crop growth.ThesisItem Embargo MORPHOLOGICAL AND MOLECULAR IDENTIFICATION OF EARWIGS (DERMAPTERA) OF SOUTH INDIA WITH INSIGHTS INTO PREDATORY POTENTIAL AGAINST FALL ARMYWORM, Spodoptera frugiperda(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga) KARTHIK, C. M.; Dr. KALLESHWARASWAMY. C M; Dr. SHARANABASAPPAThe taxonomy of order Dermaptera has been stagnant from the past two decades. This gap provides an opportunity for exploring, collecting, describing earwig fauna of South India. Surveys undertaken during 2020-22 along the selected parts of South India yielded 32 species of earwigs belonging to 21 genera of eight families including one new species and two new records from India. Among the collected samples, highest samples were represented by Anisolabididae (32.85%) followed by Forficulidae (26.49%), Chelisochidae (20.94%), Labiduridae (9.45%), Spongiphoridae (7.39%), Pygidicranidae (1.85%), Diplatyidae (0.82%) and Apachyidae (0.21%). A new species of earwig, Diplatys sahyadriensis Karthik, Kamimura and Kalleshwaraswamy, 2022 was reported for the first time in India from sugarcane and an identification key to Diplatys species of India and Sri Lanka was given. Chaetospania anderssoni and Dendroiketes corticinus were two new records from India. The specific region of mitochondrial COI (mtCOI) gene of 13 earwigs DNA was amplified and the accession numbers were obtained by submitting the sequences to the NCBIs GenBank. Phylogenetic analysis using maximum likelihood method based on mtCOI gene revealed that species belonging to Labiduridae and Forficulidae formed the basal group, while Anisolabididae formed the sister group with Pygidicranidae and Spongiphoridae. The biology of Euborellia annulata was studied on artificial diet (Dog biscuits) under laboratory condition. The incubation period recorded was 10.60 days and total nymphal period was 32.26 days. The Forficula gravelyi was tested for its efficacy as biocontrol agent on the eggs of fall armyworm, S. frugiperda showed a significant egg predation (t=19.95) (P<0.01) in laboratory. There was a significant reduction in the number of egg masses (t=-2.35) (P<0.01), larval population (t= -6.36) (P<0.01) and increased number of earwigs (t=16.90) (P<0.01) per plant in an augmented plots compared to control indicating the potentiality of F. gravelyi for exploitation as biocontrol agent of fall armywormThesisItem Open Access RELATIVE TOXICITY AND EFFICACY OF DIFFERENT INSECTICIDES AGAINST BRINJAL SHOOT AND FRUIT BORER, Leucinodes orbonalis (GUENEE)(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-11-14) G. VIRUPAKSH REDDY; Dr. S. PRADEEP; Dr. SHARANABASAPPAAn experiment was conducted under invitro and field conditions at Organic Farming Research Centre (OFRC), Navile, Shivamogga to investigate six different insecticides against Brinjal Shoot and Fruit Borer (BSFB), Leucinodes orbonalis (Guenee). Fruit dip bioassay method was followed to evaluate the relative toxicity of different insecticides against BSFB. While, chlorantraniliprole was found 11.98, 10.16, 7.19, 3.72 and 1.59 times more toxic when compared to fenpropathrin, malathion, cypermethrin, flubendiamide and spinosad, respectively. While the persistence of chlorantraniliprole 18.5 SC against the larvae of BSFB was able to continuously reduce the larval population up to 11 Days After Spray (DAS) and PT50 was around 7 days. It was followed by spinosad and flubendiamide with PT50 of 6 days and 4.5 days, respectively under laboratory conditions. In case of field conditions, all the insecticides were effective in reducing the shoot and fruit borer infestation resulting in increased marketable fruit yield over the untreated control. Among the different insecticides, The lowest mean shoot as well as fruit infestation were recorded in the experimental plots treated with chlorantraniliprole 18.5 SC at 0.4 ml/L with highest fruit yield of 17.24 t/ha and C: B ratio of 1:3.48, which was followed by spinosad 45 SC at 0.38 ml/L with fruit yield of 16.44 t/ha and C: B ratio of 1:3.27 over the untreated control.ThesisItem Embargo POPULATION DYNAMICS AND MANAGEMENT OF WHITEFLY, Bemisia tabaci (GENNADIUS) (HEMIPTERA: ALEYRODIDAE) IN TOBACCO(Keladi Shivappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga, 2022-12-18) LAVANYA, B. N; Dr. RAJASHEKHARAPPA, K; Dr. JAYALAXMI NARAYANA HEGDEThe present investigation was carried out on Population dynamics and management of whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in tobacco under field condition during 2021-22 at All India Network Project on Tobacco, Zonal Agricultural and Horticultural Research Station, Navile, Shivamogga. During the investigation, Spodoptera litura, Bemisia tabaci, Helicoverpa armigera, Myzus persicae and Trichoplusia ni were found damaging the crop. Out of the sixteen tobacco cultivars screened against whitefly infestation, five cultivars viz., Aurea, Sahyadri, Kanchana, Thrupthi and FCS-4 were proved resistant, four cultivars viz., NC-37-NF, SPEIGTT-G-28, DELCRAST-66 and RG-13 were found to be moderately resistant and remaining seven cultivars viz., Rhomas-7, REAM-151, TANTA, VA-509, VA-310, VA-21 and VA-770 were found moderately susceptible to whitefly infestation. A negative effect of trichome density on the leaf curl disease was found in resistant and moderately resistant cultivars inducing resistance to whitefly incidence, whereas leaf length, leaf width, number of leaves per plant and leaf thickness were positively correlated with the leaf curl disease. The biochemical analysis of tobacco cultivars for resistance to whitefly incidence revealed that phenols, tannins and chlorophyll had a significant negative influence on leaf curl disease exerting a direct antibiosis effect on whiteflies, while total sugar was positively associated. Among the different modules evaluated, the integrated module (Spray of seedlings with imidacloprid 0.3 ml/litre one day before planting + maize as a barrier crop + two sprays of neem oil 10,000 ppm @ 2ml/litre at 20 and 30 DAT + one spray of imidacloprid 17.8 SL @ 0.3 ml/litre at 40 DAT) was found to be most promising with lowest mean whitefly population and highest cost benefit ratio of 1:2.61 followed by chemical and bio-intensiveThesisItem Embargo MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF SPIDER MITES IN DIFFERENT AGRO-ECOLOGICAL SITUATIONS OF KARNATAKA(2022-07-16) SAFEENA MAJEED, A. A.; Dr. RAJASHEKHARAPPA, K; Dr. SRINIVASA. NInvestigations on integrated taxonomy of tetranychid mites associated with agri-horti and pasture ecosystems of Karnataka included Scanning Electron Microscope (SEM) imaging of distinctive female characters besides illustrations, diagnostic keys, molecular characterization and genetic diversity of major polyphagous spider mite species across geographical locations and host plants using nuclear gene (rDNA). 107 host plants belonging to 31 botanical families were sampled across 41 locations. A total of 35 spider mite species representing six genera (Aponychus, Eutetranychus, Petrobia, Oligonychus, Schizotetranychus and Tetranychus) and two subfamilies viz., Bryobinae and Tetranychinae were collected and identified. Of which, genus Tetranychus was more abundant (with 15 species), followed by genus Oligonychus (9 species) and Schizotetranychus (5 species). T. neocaledonicus was the predominant species found on 22 plant species in 17 locations. The study has added one new species, Oligonychus bellarensis sp. nov. and two new records, Oligonychus plegas Baker and Pritchard and Schizotetranychus approximatus Ehara to Indian tetranychid mite fauna besides redescriptions of Oligonychus tylus and Oligonychus thelytokus with several new host plant records. Oligonychus grypus Baker and Pritchard is reported for the first time from Karnataka and Pennisetum glaucum is its new host record in India, while Cymbopogon sp. is its new host record in the world. Apluda mutica, Pennisetum glaucum and Rottboellia cochinchinensis are new host records for O. tylus globally. The study deposited 77 DNA sequences (COI & ITS2) of 21 tetranychid species in NCBI-GenBank. Molecular phylogenetic analysis of major polyphagous species revealed clustering of species under genus Oligonychus is in line with the morphology-based taxonomic key, while species under Tetranychus did not show this clustering. ITS2 based genetic diversity study of major tetranychid species with wide host range revealed phylogenetic tree showing more closer relationship with host plants than the geographical locations.ThesisItem Embargo STUDIES ON GUM TECHNIQUE FOR MANAGEMENT OF COFFEE STEM BORER, Xylotrechus quadripes CHEVROLAT (COLEOPTERA: CERAMBYCIDAE)(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-07-16) AVINASH; Dr. S. PRADEEP; Dr. B K. SHIVANNAResearch was conducted to study the novel gum technique against the coffee white stem borer, Xylotrechus quadripes in various field locations in Chikkamagaluru, Karnataka during 2019-2021. Among the different methods of gum application tested, the application of gum in helical manner or helix was found to be trapping maximum beetles than other treatments. The results indicated that, the synthetic gum trapped highest beetles (0.71 beetles/plant) than the guar gum (0.14 beetles/plant) due to more stickiness and longevity. Pattern of emergence of X. quadripes was studied to identify proper timing of gum application across altitudinal gradients which revealed that, significant beetle emergence was noticed at the middle altitudinal level (0.682 beetles/infested plant) and at lower altitudinal level (0.679 beetles/infested plant), whereas in the higher altitudinal level, comparatively less beetle emergence (0.462 beetles/infested plant) was noticed. The peak beetle emergence was high in the month of October in all three altitudes studied. The evaluation of gum technique with other standard checks showed that, the gum technique evaluated as two-time gum helix and one-time gum helix recorded less number of ridges on main stem during 2020 (3.05 and 3.11 ridges/infested plant, respectively) and 2021 (3.00 and 3.05 ridges/infested plant, respectively) when compared with control plot in 2020 and 2021 (3.73 and 3.32 ridges/infested plant, respectively). Evaluation of gum technique with other techniques showed that, a considerable per cent reduction of infestation over control was seen by adopting two-time gum helix and one-time gum helix (29.41% and 23.52%, respectively). The baseline population of the X. quadripes was estimated to be 318.1 beetles/acre and the data on age of the plant, mean X. quadripes emerging from it and the relative yield can be used in cumulative loss prediction.ThesisItem Embargo MORPHOLOGICAL AND MOLECULAR IDENTIFICATION OF MEALYBUGS (HEMIPTERA: PSEUDOCOCCIDAE) IN MAJOR HORTICULTURAL CROPS(Keladi Shivappa Nayaka University of Agricultural & Horticultural Sciences, Shivamogga, 2022-07-10) KAVYA YADAV, G. A.; Dr. JAYALAXMI NARAYANA HEGDE; Dr. T. VENKATESANThe study on morphological and molecular identification of mealybugs (Hemiptera: Pseudococcidae) in major horticultural crops was carried out in the Department of Agricultural Entomology, College of Agriculture, Keladi Shivappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga during 2019-2021. During the present study, a total of 19 species of mealybugs viz., Coccidohystrix insolita, Dysmicoccus brevipes, Dysmicoccus neobrevipes, Ferrisia virgata, Formicoccus polysperes, Maconellicoccus hirsutus, Nipaecoccus viridis, Palmicultor palmarum, Paracoccus marginatus, Phenacoccus solenopsis, Phenacoccus madeirensis , Phenacoccus manihoti, Planococcus citri, Planococcus lilacinus, Pseudococcus longispinus, Pseudococcus jackbeardsleyi, Rastrococcus iceryoides, Rastrococcus invadens and Saccharicoccus sacchari infesting 154 host plants belonging to 55 plant families were recorded and maximum hosts were recorded from the family Fabaceae. Among the mealybug species, P. citri recorded highest of 17.87 per cent, followed by F. virgata and P. solenopsis with 15.15 per cent each. Phenacoccus manihoti was reported for the first time on tapioca in Karnataka from Udupi district. Mealybugs, P. madeirensis and R. invadens were reported for the first time on Noni and R. iceryoides from Karonda and Wood apple in Shivamogga district. Identification keys were developed for the 19 mealybug species belonging to 13 genera collected from different ecosystem. Using the specific primer pair ITS2 gene, 11 mealybug species were amplified and sequenced. Among 56 species of natural enemies recorded, 25 species were Hymenopteran parasitoids belonging to seven families and 31 species were predators belonging to five orders viz., Coleoptera (18 species), Diptera (8 species), Neuroptera (2 species), Lepidoptera (2 species) and Hemiptera (1 species) which were found associated with 15 different mealybug species. A total of 16 species of ants from four subfamilies viz., Dolichoderinae, Formicinae, Myrmicinae and Ponerinae were found associated with 19 mealybug species during study period.