Thumbnail Image

University of Agricultural Sciences, Bengaluru

University of Agricultural Sciences Bangalore, a premier institution of agricultural education and research in the country, began as a small agricultural research farm in 1899 on 30 acres of land donated by Her Excellency Maharani Kempa Nanjammanni Vani Vilasa Sannidhiyavaru, the Regent of Mysore and appointed Dr. Lehmann, German Scientist to initiate research on soil crop response with a Laboratory in the Directorate of Agriculture. Later under the initiative of the Dewan of Mysore Sir M. Vishweshwaraiah, the Mysore Agriculture Residential School was established in 1913 at Hebbal which offered Licentiate in Agriculture and later offered a diploma programme in agriculture during 1920. The School was upgraded to Agriculture Collegein 1946 which offered four year degree programs in Agriculture. The Government of Mysore headed by Sri. S. Nijalingappa, the then Chief Minister, established the University of Agricultural Sciences on the pattern of Land Grant College system of USA and the University of Agricultural Sciences Act No. 22 was passed in Legislative Assembly in 1963. Dr. Zakir Hussain, the Vice President of India inaugurated the University on 21st August 1964.

Browse

2020 - 202326
Reset filters
Subject: Agricultural Entomology × End date: 2023 × Start date: 2020 × Type: Thesis × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 9 of 26
  • Thumbnail Image
    ThesisItemUnknown
    SPECIES COMPOSITION, COMMUNITY STRUCTURE AND BODY SIZE PATTERNS IN FLOWER THRIPS
    (University of Agricultural Sciences, Bangalore, 2023-04-05) MANJUNATH KENCHANNAVAR; M. THIPPAIAH
    Thrips are considered as serious crop pests and vectors or crop diseases. However, their diversity and distribution stretch far beyond. Flowers being richest resources harbour diverse thrips. With astounding flower diversity, thirty species thrips, belonging to 13 genera were collected from University of Agricultural Sciences GKVK Bengaluru (Karnataka). Among which, 22 species belonged to family Thripidae of suborder Terebrantia and 8 species belonged to family Phlaeothripidae of suborder Tubulifera. During monsoon season 17 thrips species, during both winter and summer seasons 23 thrips species were recorded. In this study a new thrips species, Lefroyothrips varatharajani Rachana and Manjunath has been reported from Mimusops elengi. Looking for seasonal thrips distribution, in monsoon 39 (58.20%), in winter season 53 (49.09%) and during summer season 70 (48.27%) plant species were associated with thrips. Overall, 103 (48.81%) flowers species out of 211 were associated with 30 thrips species. Among them 58.92 % were annuals and 45.16 % were perennials. During the monsoon and the winter Thrips florum was found highly abundant followed by, Microcephalothrips abdominalis and T. palmi. While, in summer Frankliniella schultzei found highly abundant followed by M. abdominalis, T. florum and T. palmi. All together the rank abundance curve reveal T. florum as the highly abundant species (2139) followed by M. abdominalis (1457). Regarding feeding behavior, F. schultzei was a highly polyphagous thrips inhabiting 50 flower species, followed by T. florum observed in 45 flower species. At family level, F. schsultzei was found in 23 plant families. There is a greater probability of occurrence or absence of flower thrips amidst related plant species. At higher taxon level thrips showed significantly high affinity for Asterids than Rosids. Complex and aggregated distribution pattern was found in short lived N. arbor-tristis flowers than in medium and long-lived flowers like sunhemp and lark daisy.
  • Thumbnail Image
    ThesisItemUnknown
    METABOLOMIC PROFILING OF WILD TOMATO ACCESSIONS FOR RESISTANCE AGAINST Phthorimaea absoluta (Meyrick) AND Bemisia tabaci (Gennadius)
    (University of Agricultural Sciences, Bangalore, 2023-02-24) SUNIL, K.; Mohan, M.
    Tomato (Solanum lycopersicum L.) is a popular solanaceous vegetable crop grown for its edible fruit. The South American tomato leaf miner, Phthorimaea absoluta and the whitefly, Bemisia tabaci cause severe damage to tomato. To combat these pests, anti-herbivory traits of wild tomato accessions such as trichomes and defense secondary metabolites can be utilized. Trichome analysis and resistance screening study revealed that wild tomato accessions of S. cheesmaniae (VI037240-7) and S. galapagense (VI057400-3 and VI063177-10) had higher densities of glandular trichomes, particularly type-IV glandular trichomes. Both the accessions were resistant to P. absoluta and B. tabaci in no-choice and choice bioassays. UPLC-MS/MS based untargeted metabolomic profiling of wild tomato accessions following P. absoluta and B. tabaci infestation revealed different sets of resistance related constitutive (RRC) metabolites and resistance related induced (RRI) metabolites at 6 and 12 hrs post infestation (hpi). In P. absoluta and B. tabaci-tomato interaction, 1845 significant RRC and RRI metabolites that govern resistance were identified and mapped onto biosynthetic pathways. Some of the important fatty acid pathway metabolites discovered include 3-hydroxy-tetradecanedioic acid, Arachidonic acid, 12-hydroxyjasmonic acid and Monogalactosyldiacylglycerol. The identified metabolites such as 4'-Methoxychalcone, Pinocembrin 7-O-benzoate and Myricetin 3-(3'''-6'''-diacetylglucosyl) (1->4)-(2'',3'' diacetylrhamnoside) belonged to flavonoid pathway. Terpenes and steroids such as Catalpol, 2-trans,6-trans-Farnesol, 16:0-Glc-Campesterol and Solanidine are synthesized via terpenoid pathway. Atropine, Palmatine, (-)-Sparteine and Aphylline were the alkaloid pathway metabolites discovered. The differentially expressed metabolites (DEMs) of biosynthetic pathways visualized on the heat maps, indicated the differential accumulation of pathway metabolites. This plant-insect interaction study documented the secondary metabolites and their pathways that govern resistance in wild tomato accessions and these results are a valuable source of information for future pest resistance breeding prospects and to develop eco-friendly insecticides.
  • Thumbnail Image
    ThesisItemEmbargo
    MOLECULAR CHARACTERIZATION OF ACARICIDE RESISTANCE IN BROAD MITE, Polyphagotarsonemus latus (Banks) (TARSONEMIDAE: ACARI)
    (University of Agricultural Sciences, Bangalore, 2022-12-18) NEENU, AUGUSTINE; MOHAN, M
    The broad mite, Polyphagotarsonemus latus (Banks) has been a devastating pest of chilli, capsicum, mulberry and many economically important crop plants. A decreased susceptibility of this mite to commonly used acaricides was ascertained in many populations across different locations. Besides determining the baseline susceptibility of field populations of P. latus to major acaricides, genetic basis and molecular mechanisms of acaricide resistance were also investigated. Bioassays of field populations of P. latus showed varying intensity of acaricide resistance ranging from 26.03 to 81.16 folds for diafenthiuron, 27.35 to 83.47 folds for dicofol, 9.72 to 45.42 folds for fenazaquin, 8.77 to 16.84 folds for propargite and 48.37 to 163.39 folds for spiromesifen. A decline in fieldevolved resistance varying from 14.11 to 102.53 folds was observed over the generations of laboratory rearing in the absence of acaricide selection pressure. The response of P. latus to fenazaquin selection over generations revealed 11.63 folds increase in LC50 values with realized heritability (h2) value of 0.200. The de novo transcriptome sequencing of P. latus resulted in 129 million high-quality reads and 17,697,517,328 bases. From the transcriptome, 33 transcripts of cytochrome P450s (CYPs), 20 glutathione S-transferases (GSTs), 21 carboxyl/cholinesterases (CCEs) and 36 ATPbinding cassette (ABC) transporters were identified and categorized. The differential expression analysis between acaricide-resistant and susceptible samples identified a total of 4,138 up-regulated genes and 3,486 down-regulated genes. The expression stability of six housekeeping genes was studied where RPS18 and RP49 were observed to be the most stable reference genes across acaricide-resistant and susceptible populations. Validation of transcriptome data by quantitative real-time PCR for four putative CYP genes and two each of GSTs, CCEs and ABC transporter genes was performed. In accordance with the transcriptome data, the genes showed similar target regulations in response to acaricide fenazaquin selection.
  • Thumbnail Image
    ThesisItemEmbargo
    ISOLATION AND TOXICITY CHARACTERIZATION OF INDIGENOUS Bacillus thuringiensis (BERLINER) ISOLATES AGAINST TOMATO LEAFMINER, Tuta absoluta (MEYRICK) (LEPIDOPTERA: GELECHIIDAE) AND MAIZE FALL ARMYWORM, Spodoptera frugiperda (Smith) (LEPIDOPTERA: NOCTUIDAE)
    (University of Agricultural Sciences, Bangalore, 2022-12-31) NAGARAJU, M C; MOHAN, M
    The tomato pinworm, Tuta absoluta and the maize fall armyworm, Spodoptera frugiperda are the recent invasive insect pests that damages tomato and maize in India. In the absence of effective natural enemies, microbial control based on indigenous Bacillus thuringiensis strains is viewed as a viable alternative to synthetic insecticides. The present effort yielded 70 B. thuringiensis isolates by processing 300 samples collected from different states of India. All the isolates were subjected to morphological and toxicological characterization. Among the 70 isolates, 67 isolates showed bipyramidal type of crystal and the remaining three isolates showed square, elliptical and spherical crystal shapes, respectively. Detailed probit dose-mortality bioassays were conducted for 15 effective B. thuringiensis isolates. The LC50 values for the isolates tested against the larvae of T. absoluta ranged between 16.16 and 76.84 ppm at 72h. Similarly the LC50 values for the isolates tested against the larvae of S. frugiperda ranged between 56.82 and 194.59 ppm at 72h. The isolates Bt-Oa1 and Bt-257 were selected for further field testing based on their least LC90 values. On tomato, Bt-Oa1 WBF @ double the dose of LC90 (4.4 ml/lit) exhibited highest per cent larval reduction (74.60 %), similarly on maize, Bt-Oa1 WBF @ double the dose of LC90 formulation (5.2 ml/lit) exhibited highest per cent larval reduction (70.86 %). The study concluded that formulations based on indigenous B. thuringiensis could be effectively used for the management of T. absoluta on S. frugiperda tomato and maize crops respectively.
  • Thumbnail Image
    ThesisItemEmbargo
    DE NOVO TRANSCRIPTOME SEQUENCING AND GENE EXPRESSION ANALYSIS OF COTTON LEAFHOPPER, Amrasca biguttula biguttula (ISHIDA) (HEMIPTERA: CICADELLIDAE)
    (University of Agricultural Sciences, Bangalore, 2022-12-31) ARUNKUMARA, C G; JAGADISH, K S
    Investigations were carried out on insecticide resistance status, nymphal transcriptomics and expression analysis of genes related to insecticide resistance in Amrasca biguttula biguttula (Ishida) during 2018-20. Among the insecticides tested cypermethrin recorded higher (927.35 ppm) LC50 values, followed by acephate (641.63) fipronil (102.36), imidacloprid (73.39) and thiamethoxam (53.27) recorded least. Higher resistance ratios recorded in Guntur, Coimbatore and Raichur population to all insecticides and least was in Hyderabad population. The total number of assembled transcripts were 1,23,703 and 12,247 differential expression transcripts, of which 2,627 genes were down regulatedand 3,250 genes were up regulated in early versus late nymph. Higher cytochrome P450 activity was noticed in Guntur population (43.93nmol/min/mg protein), followed by Coimbatore (33.97) and Raichur (21.05), while, Hyderabad (10.71) recorded least. The Coimbatore population (1445.16) recorded highest activity of GST and Hyderbad population (1050.93) exhibited least, whereas Guntur (1404.56) and Raichur (1298.03) population showed intermediate activity. Carboxylesterase activity in ascending order: Hyderabad (1338.80) < Raichur (1593.62) < Coimbatore (1771.80) < Guntur (1961.32). Actin and alpha-tubulin were selected as suitable reference genes for gene expression. The expression of ABC transporters was high in Guntur population (1.65 folds) followed by Coimbatore (1.31) and Raichur (1.16), while Hyderabad (1.14) recorded least. The ascending order of expression of cytochrome P450 was as follows: Hyderabad (1.11 folds) < Coimbatore (1.14) < Raichur (1.18) < Guntur population (2.45). The expression of GST was high in Guntur (6.22 folds), followed by Coimbatore (1.48) and Hyderabad (1.21), the low expression was observed in Raichur population (1.16).
  • Thumbnail Image
    ThesisItemEmbargo
    DIVERSITY AND MOLECULAR CHARACTERISATION OF NATURAL ENEMY COMPLEX AND EVALUATION OF BIO CONTROL STRATEGIES AGAINST MAJOR INSECT PESTS OF BHENDI (Abelmoschus esculentus L. Moench)
    (University of Agricultural Sciences, Bangalore, 2022-12-30) ARAVINDA; Shylesha, A N
    Bhendi or Okra Abelmoschus esculentus L. Moench) is one of the important vegetable crop, which is growing throughout the India. Due to ill effect of chemicals, usage of botanicals, bio pesticides and natural enemies, is an ecologically viable option for sustainable pest management. The experim ents were conducted during rabi 2019, S ummer 2020 and k harif 2020 on bhendi crop to study the population dynamics of sucking pests and their natural enemies The results revealed that t he activity of insect pests such as aphids, leafhoppers, were more in k harif , the whiteflies activity was more in s ummer. The activity of predators like ladybird beetles and spiders were more in k harif The population of total predatory and parasitoids fauna occurring in bhendi field viz., ants 20 species ), spiders 17 species ), coccinellids 11 species ), other predators 12 species like green lacewing, praying mantis, earwigs, etc.etc., and Hymenopteran parasitoids 24 species About 17 species of natural enemies were molecularl y characterized and their sequence in the range of 532 to 658 bp product of COI gene and their accession numbers obtained from NCBI data base T he botanicals and mycopathogens were evaluated against sucking pests of bhendi. The result revealed that, among the treatments L ecanicillium lecanii Zimmerman ) @5g/l , was found to be superior against leafho ppers and whiteflies and Neem oil @ 0.5%, was found effective against aphid’s population. Field evaluation of braconid parasitoids against t he larval population fruit borers like Earias vittella (Fab and Helicoverpa armigera Hubner were showed that Trichogramma chilonis Ishii + Chelonus blackburnii ( Bracon brevicornis (Wesmael) is the most superior combination of parasitoids in larval parasitization. The parasitic potential of B. brevicornis was and C. blackburni was evaluated against the fruit borers . The result revealed that, the highest parasitization of B. brevicornis and C. blackburni was in 5:10 and 5:100 parasitoid host ratio respectively.
  • Thumbnail Image
    ThesisItemOpen Access
    DEVELOPMENT AND VALIDATION OF INTEGRATED PEST MANAGEMENT COMPONENT TECHNOLOGIES AGAINST TUTA ABSOLUTA (MEYRICK) (LEPIDOPTERA: GELECHIIDAE) ON TOMATO
    (University of Agricultural Sciences, Bangalore, 2020-11-20) APARNA, s; Kumar, A.R.V.
    derstanding agro-ecology is a prerequisite for development of Integrated Pest Management components for invasive pest like Tuta absoluta affecting tomato. In the present study, a survey of was conducted in three clusters of southern Karnataka to understand the cultivation practices of farmers. Farmers in different clusters followed different agronomic practices and differed in their attitude towards IPM components. The knowledge regarding the pest and its symptoms were limited among the farmers. Pest incidence was higher in Summer than in other seasons. T. absoluta showed differential preference to plant parts in each phenological stage owing to the resource dynamics.Oviposition preference assays were conducted on six Solanaceous species which revealed that tomato was the most preferred plant followed by potato, brinjal and S. nigrum. All the parameters that contributed to fitness of the insect were high on tomato compared to other hosts. Study showed that NSKE (5%) treated plants were significantly less preferred for oviposition than non-treated plants, while Trichoderma treatment was not effective. LC50 values of Spinetoram 11.7 % SC, Spinosad 45 % SC, Azadirachtin 1% EC, NSKE (5%), Bt kurstaki and Chlorantraniliprole 18.5% SC were estimated and their efficacy was evaluated both in field and polyhouse conditions. Spinosad derivatives were effective compared to neem and Bt products as seen from the reduced larval load on leaves and fruits. The pest incidence can be managed by using neem spray as oviposition deterrent and Spinosad derivatives as larvicidal sprays. Clean cultivation and crop rotation with non Solanaceous crop reduce the pest incidence.
  • Thumbnail Image
    ThesisItemOpen Access
    POPULATION DYNAMICS OF THRIPS AND THEIR ASSOCIATION WITH BUD NECROSIS VIRUS DISEASE IN TOMATO
    (University of Agricultural Sciences, Bangalore, 2020-11-19) TIMMANNA; TIMMANNA; MOHAN, I. NAIK; MOHAN, I. NAIK
    Population dynamics studies carried out at IIHR, Bangalore during kharif and rabiseasons of 2016 and 2017 indicated that, there were three thrips species viz., Thrips palmiKarny, Scirtothrips dorsalis Hood and Frankliniella schultzie Trybom occurred together in tomato crop. Thrips population gradually increased from vegetative to flowering and fruiting stage and gradually decreased as crop matures. The Zoophytophagous miridbug,Nesideocoris tenuis Reuter population increase was linear with thrips population. The highest mean thrips (kharif and rabi : 3.85 and 6.15/top 3 leaves) observed during 2ndweek of July (28th SMW) and 3rd week of November (47th SMW) and 23.87 per cent and 34.05 per cent of cumulative GBNV disease incidence was observed. Correlation analysis on weather parameters revealed that, during kharif highly significant negative correlation was observed between thrips and GBNV disease with rainfall (r=-0.861**and r=-0.715**). During rabi thrips and GBNV disease had highly significant negative relationship with morning relative humidity (r=-0.742** and r=-0.711). Stepwise linearregression analysis revealed that, thrips population was highly influenced by rainfall (73%), sunshine hours (67 %), and morning relative humidity (60 %). GBNV disease was more influenced with maximum temperature (84%). Minimum temperature (71%) and rainfall (63%). Transmission studies indicated that, a single, T. palmi could able to transmit GBNV, whereas in case of S. dorsalis, two thrips adult required for minimum GBNV transmission. Virus transmission increased with the concomitant increase ofthrips number, maximum transmission (100.00 %) achieved with 10 Thrips palmi adults per seedling and found efficient transmitter of GBNV than the Scirtothrips dorsalis (41.67 %). Concomitant increase in feeding periods increases the virus transmission. The bioassay studies revealed that, the lowest LC50 values were recorded in spinosad andthiamethoxam and they were found to be more toxic to thrips as compared to the other insecticides tested.
  • Thumbnail Image
    ThesisItemOpen Access
    AUGMENTATION OF THE PREDATORY BUG Eocanthecona furcellata Wolff (HEMIPTERA: PENTATOMIDAE) FOR MANAGEMENT OF PEST COMPLEX OF BRINJAL AND TOMATO
    (University of Agricultural Sciences, Bangalore, 2020-12-06) ACHANTA, SRAVIKA; SHYLESHA, A N
    The integration of biocontrol strategies for management of lepidopteran pests of brinjal and tomato provide sustainable solution. Eocanthecona furcellata Wolff. is considered as one of the potential predators against lepidopteran pests. The peak population of E. furcellata was observed during winter than summer months. The predation rate of E. furcellata on lepidopteran pests of tomato and brinjal studied suggested that females required more prey than males in order to prepare for egg production. The finite predation rate (ɷ), intrinsic predation rate, net consumption rate (C0) and stable predation rate (Psi) of E. furcellata were significantly higher on earlier instars than on later instars of prey larvae provided. Studies on biology, reproductive and life table parameters of E. furcellata on various lepidopteran hosts showed that the mass rearing of E. furcellata was feasible on three hosts, Samia cynthia ricini, Corcyra cephalonica and Galleria mellonella due to the ease of their mass rearing, availability throughout year and low rearing costs. The characters like higher fecundity, high survival and feasibility of group rearing of E. furcellata are amenable features for mass rearing. Under field condition the per cent reduction over control of Leucinodes orbonalis and Helicoverpa armigera infestation by fifth instars of E. furcellata was up to 36.9 and 39.7 per cent, respectively. Five releases of E. furcellata at weekly interval were effective in reducing the incidence of L. orbonalis and H. armigera. Hence, these predatory bugs could be promoted for suitable biological control programs to regulate the lepidopteran pests of brinjal and tomato.