Browsing by Author "Saniya Tyagi"

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Bacterial community of brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) revealed by high throughput amplicon sequencing
(Horizon e-Publishing Group, 2025) Saniya Tyagi; Narayana Srinivasa; Rajendra Nath Singh; Varun Arya
The bacterial symbionts of brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a key sucking insect pest of rice in India and Asia, have been known to play many important physiological functions. Reports of yeast-like symbionts of N. lugens are widely known, but little is known about the bacterial microbes. In this study, the bacterial community structure and diversity were examined in N. Lugens collected from four major rice-growing regions of India utilizing culture-independent high throughput sequencing. The Mi seq technology identified a total of 1277 operational taxonomic units (OTUs) representing 4 phyla mainly (Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes) by analyzing 16S rDNA gene libraries. The major microbial groups were similar in the four samples, but their distribution patterns were different, especially in Raichur. While the top three bacterial genera linked to Imphal, Pantnagar and Raichur were Methylobacterium, Sphingomonas and Acinetobacter; Wolbachia accounted for 87.46 % of the total genera found in Raipur. The identified dominant microbial groups have been known for their crucial role in insect’s life cycle. Diversity analysis tests revealed Raichur has the highest species diversity as determined by the high Shannon and Simpson index. According to ACE and Chao1 diversity estimates, Pantnagar has the highest species richness. Understanding the bacterial communities and studying their functional roles will help in formulating biological control strategies specific to this sucking pest. © The Author(s).
DNA barcoding and genetic diversity studies of Water lily aphid, Rhopalosiphum nymphaeae from India
(Triveni Enterprises, 2025) Vinod Kumar Padala; Twinkle Sinha; Saniya Tyagi; N. Ramya; Narayana Srinivasa
Aim: In this study, DNA barcoding of Rhophalosiphum nymphaeae was conducted using a population collected from five different aquatic host plants, and the genetic diversity analysis was performed. Methodology: Genomic DNA from R. nymphaeae adults was extracted and the COI gene was amplified using PCR. The PCR products were sequenced, analyzed for identification using NCBI and BOLD databases, and the sequences were submitted to NCBI GenBank. Further genetic analysis were conducted to study the genetic diversity of the pest. Results: Two new aquatic weed hosts of water lily aphid was reported from India, i.e., Blue water lily, Nymphaea nouchali Burm. f., and Four leaf clover, Marsilea quardrifolia L. The genetic diversity analysis revealed the lesser diversity among the Indian and USA population of water lily aphid as compared to the populations from China, Canada and Lithuania. Interpretation: The genetic diversity analysis indicated no genetic variation in the Indian population, however, a moderate level of variation was observed in the rest of the world population. This work will facilitate the quick identification of R. nymphaeae independent of sex and stage, furthermore helping in either pest management or its use as bio-control agent. © 2025 Triveni Enterprises. All rights reserved.
DNA barcoding of fruit flies associated with cucurbit ecosystem and combination of Cue-Lure and Methyl Eugenol in trap is not effective for mass trapping of responsive fruit flies
(Springer Science and Business Media B.V., 2022) Varun Arya; Srinivasa Narayana; Saniya Tyagi; Samantapudi Venkata Satyanarayana Raju; Chandra Prakash Srivastava; Twinkle Sinha; Pratap Divekar
Fruit flies are key pests of vegetable crops, particularly cucurbits. Depending on the fruit fly species, the parapheromone, cue-lure (CL) or methyl eugenol (ME) is used in traps for monitoring and mass trapping. Many species of fruit flies belong to the genus Bactrocera and Zeugodacus which infest cucurbits and are responsive to CL and ME. Preparation and application of individual lures of CL and ME is uneconomical and laborious. Therefore, the present investigation was undertaken to document fruit flies associated with the cucurbit ecosystem, their diversity using CL and ME baited traps and to study the feasibility of combination of CL and ME in the trap for mass trapping of responsive fruit flies. Six species of fruit flies were found to be associated with the cucurbit ecosystem, viz., Zeugodacus cucurbitae, Z. tau, Bactrocera dorsalis, B. zonata, B. digressa and B. correcta. These species were identified using taxonomic keys and DNA barcoding. Bactrocera digressa was recorded for the first time from Uttar Pradesh (India) and it is also attractive to both CL and ME. The mitochondrial cytochrome oxidase I barcodes of B. digressa are novel to India. Though six species were collected in the lures, it was Z. cucurbitae and Z. tau that actually infested cucurbits, ascertained from fruit fly emergence from infested cucurbits, indicating the seriousness of pests. The population of Z. cucurbitae and B. dorsalis was found to be more in CL (p = 0.03308) and ME (p = 0.0159) respectively than in the ME/CL combination. The study thus indicated that the combined use of lures, CL and ME in single trap significantly reduces the trap catches of responsive fruit flies. The phylogenetic analysis revealed two distinct clades, i.e., one for fruit flies responsive to CL and another one for ME. Our findings are anticipated to have significant implications for pest identification, monitoring and management. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.
Insect biodiversity conservation: Why it's needed?
(Apple Academic Press, 2024) Saniya Tyagi; Radheshyam Dhole; N. Srinivasa; N. Vinay
Insects, the most abundant creatures on earth, in terms of both number and diversity, are often taken for granted by the masses due to either negligence or the annoyance that a few species create. Insects are an imperative part of the majority of the food webs that exist across the globe and also play a significant role in the functioning of the ecosystem. Moreover, insects regulate environmental sustainability in many ways such as by pollinating plants, cycling up nutrients, maintaining the structure and fertility of solum, decomposing various organic matter, etc. However, this harmony is now disturbed due to the worldwide increase in anthropogenic activities in the last few decades, leading to significant biodiversity losses in insects. Global pollution, climate change, and habitat demolition are some of the major causes of insects decline. Thus, to maintain the ecological balance and for our survival also, new and efficient efforts on conservation of insects and their diversity are needed immediately. © 2025 Apple Academic Press, Inc. All rights reserved.
Migratory behaviour of Brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), in India as inferred from genetic diversity and reverse trajectory analysis
(Springer Science and Business Media Deutschland GmbH, 2022) Saniya Tyagi; Srinivasa Narayana; R.N. Singh; C.P. Srivastava; S. Twinkle; Sanat Kumar Das; Mallikarjuna Jeer
The brown planthopper, Nilaparvata lugens (Stål) is a major sucking insect pest of rice. This insect has long been considered as migratory; however, its route in India is still unknown. Hence, to find out its migration route genetic diversity, genetic structure and gene flow of 16 N. lugens populations from major rice growing regions of India was studied based on mitochondrial cytochrome oxidase I (COI). The results revealed a high genetic homogeneity among the populations on the basis of genetic diversity statistics and neutrality tests. There was a prevalence of a single major haplotype across the country. No spatial relevance was found with the genetic structure of the populations indicating presence of excessive gene flow among them. Extensive gene flow among populations was also confirmed with the presence of higher number of immigrants in North, Central, and East India. To further clarify the migration sources, 48 h air-mass reverse trajectory was performed for Varanasi just aftermath of cyclones Amphan and Yaas, which disclosed Eastern/Northeastern states along with Bangladesh and Myanmar as the possible source areas. Overall, the results revealed a single panmictic homogeneous population of N. lugens in India with extensive gene flow as a consequence of their migration. These findings will help in better forecasting enabling efficient regional management of this important rice pest. © 2022, King Abdulaziz City for Science and Technology.
Molecular Insights into Wing Polymorphism and Migration Patterns of rice Planthoppers
(Springer Nature, 2022) Saniya Tyagi; Srinivasa Narayana; Rajendra Nath Singh; G. Basana Gowda
Planthoppers are major plant pests in several cultivated ecosystems worldwide. In most situations, like the rice ecosystems in Asia, they represent a complex of cryptic species. They inflict direct as well as indirect damage on rice by serving as disease-causing virus vectors. Planthoppers are seasonal migrants, of which economically important pests, such as Nilaparvata lugens, Sogatella furcifera, and Laodelphax striatellus, show wing dimorphism. Long-winged morphs are suitable for long-distance migration, while short-winged morphs for local colonization. The wing polyphenism is regulated by environmental cues, host plant nutrition, and other abiotic factors. Juvenile hormone, miRNA, insulin receptors pathway, and 20-hydroxy ecdysone form an autoregulatory feedback loop to regulate wing polyphenism in N. lugens. In India and other countries in Southeast Asia, rice planthoppers are seasonal migrants from south to north. Specifically, Indochinese peninsular region is the main source of N. lugens migratory population to temperate part of China and most probably to Japan. Similarly, the Greater Mekong Subregion (GMS) is the source of migratory population of S. furcifera to Yunan province of China. Migratory pathways of planthoppers have been elucidated efficiently with nuclear (simple sequence repeats, single nucleotide polymorphism) markers, mitochondrial (MtCo1) markers, and recently with more powerful whole-genome sequencing by evaluating genetic structure of different populations. Understanding migratory behavior of planthoppers will help in developing effective pest management strategies. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
MORPHOLOGICAL AND BIOCHEMICAL BASIS OF RESISTANCE TO POD BORER HELICOVERPA ARMIGERA IN PIGEONPEA
(The Entomological Society of India, 2022) Saniya Tyagi; Ram Keval; Sunil Verma; Dhruba Narayan Kohar
This study evaluates sources of resistance to the pod borer Helicoverpa armigera (Hubner) in 15 long duration pigeonpea genotypes with experiments done during 2017-19. Association of morphological and biochemical traits was also evaluated. The results revealed that the least pod damage was attributed to high phenol content in pods (-0.668**), seeds (-0.719**) and high trichomes density (-0.637*). The susceptibility of genotypes (IVT-1-903, IVT-12-904, IVT-703) was indicated by their high pest susceptibility rating (PSR), and due to greater pod length (0.563*) and width (0.603**). The activity of protein, reducing sugars, chlorophyll, carbohydrates, pod wall thickness and number of seeds/ pod was also studied. Genotypes IVT-705, IVT-706 and IVT-1-901 emerged out to be the least susceptible (PSR = 4). Role of these traits are discussed to identify basis of resistance. © 2019, The Entomological Society of India. All rights reserved.
Physicochemical traits of pigeonpea genotypes and resistance to pod fly Melanagromyza Obtusa (Malloch)
(The Entomological Society of India, 2021) Saniya Tyagi; Ram Keval
Resistance to the pod fly in 15 long duration pigeonpea genotypes is evaluated in this study done during kharif 2017-18 and 2018-19. Also, the variability in their physicochemical traits (pod length, pod width, number of grains per pod, pod wall thickness, trichome density, carbohydrate, protein, reducing sugars, phenol, and chlorophyll) has been studied. The results revealed that the pod length showed a positive correlation, whereas pod wall thickness and trichome density showed negative correlation with pod fly damage. The genotypes IVT-706, IVT-705 and IVT-208 showed less damage because of these. The genotypes having more protein, reducing sugar and carbohydrates were found to be more prone. Phenol content was negatively correlated with damage (r =-0.618). Overall, the genotypes IVT-705, IVT-706 and IVT-12-904 were found to be least susceptible to pod fly damage. © 2021, The Entomological Society of India. All rights reserved.
Species-specific markers for Nilaparvata lugens and Sogatella furcifera (Hemiptera: Delphacidae) based on mitochondrial cytochrome oxidase I
(Springer Science and Business Media Deutschland GmbH, 2023) Saniya Tyagi; Narayana Srinivasa; R.N. Singh; N. Vinay
Brown planthopper (BPH), Nilaparvata lugens (Stål) and white-backed planthopper (WBPH), Sogatella furcifera (Horváth) are the most destructive sucking insect pests of rice in all rice growing parts of the world. For their accurate identification at early stages, we have developed two species-specific markers (SNL4F and SNL4R for BPH; SNF2F and SNF2R for WBPH) based on mitochondrial cytochrome oxidase I (COI) for their easy detection using Polymerase Chain Reaction (PCR). The markers were developed based on nucleotide differences in COI gene and were subjected to various tests based on PCR-based gel images. The designed primers were cross-checked with five other species, which confirmed their specificity. The primers were also found to be efficient in identification of their respective species (BPH and WBPH) in all the individuals sampled from different regions of India. The lowest detection sensitivity of both the primers was up to 1 ng/µl DNA after testing them through a series of varied DNA concentrations. The species-specific primers developed in this study will help in easy and rapid identification of BPH and WBPH in all the stages of their development and in turn facilitate their timely management. © 2023, King Abdulaziz City for Science and Technology.