Scirpophaga Incertulas Research Articles

Diversity and Abundance of Soil Collembola during GM Rice Overexpressing Cry1B-Cry1Aa Cultivations at Four Confined Field Trials in West Java.

Collembola (springtails) is an important soil biology indicator to monitor toxicity or ecological disturbances in the ecosystem. The impact of Bacillus thuringiensis (Bt) rice cv Rojolele events expressing Cry1B-Cry1Aa driven by the maize ubiquitin promoter resistant to yellow rice stem borer (YSB, Scirpophaga incertulas Walker) on non-target Collembola community was assessed. The experiment was performed at four locations under confined field trials according to the Indonesia's environmental safety regulation on genetically engineered crops. Six transgenic rice events were tested with non-transgenic Rojolele and the moderately resistant IR42 rice varieties as controls. The experimental design was randomised block design with three replicates. Collembola were collected from the bunds between plots using pitfall and Berlese funnel traps at seedling, vegetative and generative stages, as well as at harvesting time. The results showed that Collembola abundance and diversity were significantly affected by both experimental sites and observation times. However, no significant differences in Collembola diversity and abundance between Bt rice and non-Bt controls were observed. Thus, we can conclude that the cultivation of the Bt rice cv Rojolele events expressing Cry1B-Cry1Aa protein fusion do not adversely affect biodiversity and abundance of Collembola at the four confined rice fields.

Review on bionomics and management of rice stem borer

Rice (Oryza sativa L.) is used as staple food for the overwhelming majority of the world’s population. Rice production hampered mostly by stem borers like, yellow stem borer (Scirpophaga incertulas) pink stem borer (Sesamia inference), dark headed stem borer (Chilo polychrysus), stripped stem borer (Chilo suppressalis). For minimize the infestation farmers use different resistant rice cultivars like, TKM 6, PTB 10, Su Yai 20, Mudgo, DV 139, Taitung 16, Gontra Bidhan 3, MTU-2020, IR 50, NDR-97, etc. against stem borer population. For controlling deleterious pest population farmers mostly use insecticide which exhibit good results than any botanicals against rice pests. Other techniques including using microbial pesticides, other biocontrol agents, use of pheromones or allomones, staggered planting, synchronized planting, removal of infected leaves, steams with pruning shears, using of trap crop, etc. are effective for control rice pests. But indiscriminate use of chemical insecticides results in great economic loss with destabilizing of biodiversity and resulting cross resistance against insecticides. So, pest population ecology based sustainable management strategies of such pest species is very essential for climate smart pest management (CSPM) as well as climate smart agriculture (CSA) of rice and other crops in the near future.

PRODUCTIVITY OF FOUR RICE VARIETIES AND PEST DISEASES WITH THE APPLICATION OF ENVIRONMENT FRIENDLY AGRICULTURE TECHNOLOGY IN JAKEN, PATI, CENTRAL JAVA

Pest and disease attacks are factors that affect the production and productivity of rice plants. The approach of environment friendly agriculture technology is expected to be able to overcome the problems of pests and diseases and increase the production and productivity of rice plants. This study aims to determine the productivity of four rice varieties and the intensity of pest and disease attacks on the application of environment friendly agriculture technology. This research was conducted in Jaken, Pati district, Central Java, from November 2019 – March 2020. This study used a purposive sampling method with a Randomized Group Design (RGD). Rice variety is the single factor in this study. The rice varieties used consisted of Inpari 32, Cigeulis, Inpari 43 and M400. The components of environment friendly agriculture technology used are the use of biochar-compost (biocompost), charcoal-coated urea or biochar, and the use of biopesticides as pest control. Observations were made on growth, productivity and intensity of pest and disease attacks. The results showed that the varieties produced high productivity were Inpari 43 (4.91 t ha-1) and Inpari 32 (5.83 t ha-1). The high pest attack was the yellow rice stem borer (89.47%) on the M400 variety and the brown planthopper (7.69%) on the Cigeulis variety. The intensity of blast disease and bacterial leaf blight were highest at 14.97% and 5.99%, respectively, in the M400 variety.

Evaluation of long duration Promising Rice Genotypes for Resistance to Stem Borer, Scirpophaga incertulas (Walker) and gall Midge, Orseolia oryzae (Wood- Mason)

Field evaluation of sixteen promising rice genotypes under natural infestation of stem borer and gall midgewas carried out at Agricultural Research Station, Nellore, Andhra Pradesh over two consecutive yearsduring kharif season. The results revealed that out of 16 genotypes screened, NLR 3763 during 2019-20 andNLR 3747 and NLR 3742 during 2020-21 recorded highly resistant reaction to stem borer with nil deadheart incidence at 30 DAT. Six rice genotypes viz., NLR 3745, NLR 3749, NLR 3750 NLR 3753, NLR 3762and NLR 3765 consistently reported resistant reaction (Scale 1) to stem borer during two years of study andat 30 and 50 DAT with dead heart incidence less than 10 per cent. Regarding gall midge although fivegenotypes viz., NLR 3744, NLR 3747, NLR 3748, NLR 3749 and NLR 3753 at 30 DAT and one genotypeNLR 3750 at 50 DAT found highly resistant (score 0) with nil gall midge incidence during 2019-20 theirexpression was not consistent. The genotypes NLR 3752, NLR 3753, NLR 3763, NLR 3762, NLR 3760 andNLR 3765 showed consistent results with moderately resistant reaction to gall midge during two years ofstudy period at 30 DAT. More over NLR 3753 consistently reported highly resistance reaction at 30 DATand became moderately resistant at 50 DAT during two years of study.

Volatile Profiles as Affected by Rice Brown Plant Hopper and Yellow Stem Borer in Rice Landraces

Rice (Oryza sativa L.,) plants release a complex profile of volatile organic compounds. Present study investigates the differences in volatile compounds from four rice landraces viz., Karuthakar, Norungan, Thavala Kanan and Varappu Kudaichan each under four conditions like healthy, mechanically damaged, and the ones infested by the brown plant hopper Nilaparvata lugens Stal and yellow stem borer Scirpophaga incertulas (Wlk.). The volatiles were collected using air entrainment method and characterized by the GCMS. Statistical analysis tools like clustering, principal component analysis and partial least square discriminant analysis were applied. Clear differences among the treatments were observed and certain volatile compound groups like terpenoids (squalene), unsaturated fatty acids (n-hexadecanoic, tetradecanoic and pentadecanoic acids), alkanes (heptacosane, tetracosane) were found. The statistical test of Partial Least Square Discriminant Analysis was found to be satisfactory in determining the compounds responsible for variations in treatments.

Efficacy of Botanical Extracts Against Rice Stem Borer <i>Scirpophaga Incertulas</i> (Walker)

Efficacy of botanical extracts was evaluated against the rice stem borer Scirpophaga incertulas (Wlk.) at PAJANCOA and RI, Karaikal during kharif 2019 and rabi 2019-2020. The results revealed that thiamethoxam 25WG @ 100 g/ ha reduced incidence to 4.99% and 4.13% (52.15 and 61.80% reduction, respectively). Among the botanicals, garlic and chilli extract 5% reduced this to 5.69% and 5.48%. The predatory coccinellids and spiders were more in untreated check and it was found at par with garlic and chilli extracts at 5%, followed by five leaf extracts @10% and bitter apple leaf extract 10%. The benefit cost ratio (BCR) was maximum with thiamethoxam 25WG @ 100 g/ ha (1: 1.67 and 1: 2.10), followed by garlic and chilli extract 5% (1: 1.59 and 1:1.91).

Isolation and Functional Characterization of a Green-Tissue Promoter in Japonica Rice (Oryza sativa subsp. Japonica).

Simple SummaryTransgenic applications have largely focused on constitutive promoters in plants. However, strong and continuous over-expression of certain genes may be redundant and even harmful to plant growth. Thus, tissue-specific promoters are the most suitable for regulating target gene expression. Although several tissue-specific promoters have been identified, the regulatory mechanism of tissue-specific gene expression remains unclear. By a series of GUS staining of 5′ and 3′ deletions, we uncover tissue-specific cis-acting elements in GSX7R, including ten light-responsive elements. The results reveal that GSX7R is a reverse green tissue-specific promoter, except in endosperm. In contrast, strong tissue-specific promoters that can be used for rice improvements are limited. In this study, we successfully showed that the GSX7R promoter can drive the Cry1Ab gene to resistant rice yellow stem borer. In addition, our study demonstrates an effective promoter to drive foreign genes for crop improvement.Plant promoters play a vital role in the initiation and regulation of gene transcription. In this study, a rice protein/gene of unknown expression, named Os8GSX7, was gained from a rice T-DNA capture line. The semi-quantitative RT-PCR analysis showed that the gene was only expressed in root, glume, and flower, but not in stem, leaf, embryo, and endosperm of japonica rice. The GUS activity analysis of the GSX7R promoter showed that it was a reverse green tissue expression promoter, except in endosperm. The forward promoter of GSX7 cannot normally drive the expression of the foreign GUS gene, while the reverse promoter of GSX7 is a green tissue-specific expression promoter, which can drive the expression of the foreign GUS gene. The region from −2097 to −1543 bp was the key region for controlling the green tissue-specific expression. The regulatory sequences with different lengths from the 2097 bp reverse sequence from the upstream region of the Os8GSX7 were fused with the GUS reporter gene and stably expressed in rice. Furthermore, transgenic rice plants carrying Cry1Ab encoding Bacillus thuringiensis endotoxin, regulated by GSX7R, were resistant to yellow stem borer. The analysis suggested that 10 light responsive elements of tissue-specific expression were found, including ACE, Box4, CAT-box, G-Box, G-box, GATA motif, GC motif, I-box, Sp1, and chs-unit1 M1. In addition, the results of 5′ and 3′ deletions further speculated that ACE and I-box may be the key elements for determining the green tissue-specific expression of GSX7R promoter.

Does solar light trap reduce the cost of pesticides used in rice field?

Pesticide application against insect pest infestation is environmentally unsafe and costly. An attempt was taken to evaluate the solar light trap as ecofriendly and cost-effective approach in Transplanted Aman rice (BRRI dhan32) field at Barhatta Upazila (Sub-district) in Netrokona district of Bangladesh. It was found that rice pest like Rice yellow stem borer, Rice leaf roller, Green leaf hopper, Brown plant hopper, Rice leaf miner, Rice gall midge, White leafhopper, Rice bug, Rice ear cutting caterpillar, White-backed planthopper, Rice caseworm, Grasshopper, Rice skipper and Rice beetle were the major insects that captured under the solar light traps. Some beneficial insects were also attracted by the trap these were Ladybird beetle, Water scavenger, Giant water bug, Ground beetle, Rove beetle, Damsel fly. All the harmful and the beneficial insects were belonging the order of Lepidoptera, Hemiptera, Orthoptera, Coleoptera, Diptera and Odonata. Though the mean yield of rice was statistically insignificant in both fields, the light trap installed fields required the less frequency of pesticides than the control fields which ultimately rendered the low pesticides cost in a great extent. On an average 1,034 BDT was reduced in per hectare. SAARC J. Agric., 20(1): 171-183 (2022)

Bioefficacy of certain chemical insecticides against rice yellow stem borer (Scirpophaga incertulas Wlk.)

Rice is the major staple food in Jharkhand in India and is threatened by various biotic and abiotic stresses. Among the insect pests that imperil the rice cultivation in Jharkhand, the yellow stem borer (Scirpophaga incertulas Wlk.) is one of the most notorious ones. The present investigation was conducted in Kharif 2018 to study the bioefficacy of certain chemical insecticidal treatments against yellow stem borers in rice measured in terms of mean values of dead heart (% DH) and white ear (%WE). Ten insecticidal treatments, namely, T1 - Flubendiamide 240 SC + Thiacloprid 240 SC (combination product) @ 200 ml/ha, T2 - Flubendiamide 240 SC + Thiacloprid 240 SC (combination product) @ 250 ml/ha, T3 - Imidacloprid 17.8 SL @150 ml/ha, T4 - Flubendiamide 480 SC @ 50 ml/ha, T5 - Rynaxypyr 20 SC @150 ml/ha, T6 - Fipronil 80 WG @ 65 g/ha, T7 - Dinotefuran 20 SG @ 200 g/ha, T8 - Fipronil 0.3 GR followed by Chlorpyriphos 20 EC @2000 ml/ha, T9 - Chlorpyriphos 20 EC@ 2000 ml/ha and T10 - untreated control were taken for the experiment. The results showed that two of the insecticidal treatments,namely T2- flubendiamide 240 SC + thiacloprid 240 SC @ 250 ml/ha (2.07% DH and 2.30% WE) and T4 - flubendiamide 480 SC @ 50 ml/ha (1.89% DH and 2.49% WE), were at par with each other. They performed better than all the other treatments, suggesting that using these two newer insecticidal treatments could provide all-around protection for the rice crop against rice yellow stem borer in terms of both dead heart and white ear.

Biochemical factors associated with vegetative phase resistance against yellow stem borer, Scirpophaga incertulas (Walker) in land races of rice

A total of 50 local land races were screened against infestation of yellow stem borer, Scirpophaga incertulas (Crambidae: Lepidoptera) at vegetative phase under natural infestation (0 to 65%) during kharif 2019. Among them 18 land races were selected from each category of resistance based on standard evaluation system for rice. The estimation of biochemical constituents in rice stem (60 days old plants) of different categories was done to establish a relationship between various biochemical components with resistance/ susceptibility. Studies revealed that higher amounts of total sugars, reducing sugars and crude proteins were found in susceptible lines compared to resistant land races and were positively correlated with stem borer infestation. Total free amino acids, total phenols and tannins were found to be higher in resistant than susceptible varieties and were negatively correlated. The mineral content in the stem viz., nitrogen was positively correlated whereas phosphorous and potassium were found in higher quantities in resistant categories (2.19 – 2.37%) than susceptible ones and were found to be negatively correlated with infestation of yellow stem borer (-0.95).

Population dynamics of rice yellow stem borer and sheath blight

Field experiments were conducted on the seasonal incidence of yellow stem borer (Scirpophaga incertulas) and sheath blight (Rhizoctonia solani). These revealed that maximum deadheart incidence (5.32 and 5.64%) was observed in the 33rd and 34th standard meteorological week (SMW) in 2018 and 2019, respectively. The incidence of white earhead was maximum (4.96 and 5.28%) during 40th SMW. Maximum incidence of sheath blight (50 and 46.67%) was noticed during 36th SMW. A significant positive correlation of minimum temperature and evening relative humidity was found with deadheart incidence. Conversely, maximum temperature and morning relative humidity had significant positive correlation with incidence of sheath blight. The model developed for ascertaining effect of weather factors on incidence of pest and disease showed a good relationship between predicted and observed data of % deadheart (R2=0.996), white earhead (R2=0.992) and diseased plants (R2=0.986).

Novel Formulation of Herbal Pesticide for Rice Cultivation

The irrational use of chemical pesticides has caused serious health hazards and environmental problems in developing countries including India. Hence, the Present investigation was carried out to formulate an effective Herbal pesticide against three major pests of rice like stem borers, leafhoppers and plant hoppers and to find solution for control of pest population by traditional agricultural practices. Oil of Azadirachta indica, Vitex nigundo, Ipomoea carnea, Adhatoda zeylanica and natural surfactant are the main constituents used in the formulations. Larvae of stem borers in the infected stem and hopper damaged part of the plant were selected for the study. A total of six herbal formulations at four different concentrations were sprayed on larvae of stem borers and hopper damaged parts of plants. The developed herbal pesticides have been validated in the field as well as in lab conditions and larval mortality rates were observed. After treatment, the population of pests decreased gradually and the mortality rate of larvae increased. Herbal pesticides focus on providing solutions and relief from various types of insects that cause massive damages to the plants being grown on a farm. These products were made of natural materials that have properties of killing or keeping out pests within the range of the field. The results showed that the extent of growth of these pests was less when compared to control and minimum occurrence of pest attack and Percent Dead Heart (DH) was confirmed in response to herbal formulations. The foremost benefit of this herbal pesticide is managing the Yellow Stem Borer (YSB) pest population and providing healthier cropping systems. Hence it is recommended to use this herbal pesticide for disease free sustainable cultivation of organic rice.

Novel Formulation of Herbal Pesticide for Rice Cultivation

The irrational use of chemical pesticides has caused serious health hazards and environmental problems in developing countries including India. Hence, the Present investigation was carried out to formulate an effective Herbal pesticide against three major pests of rice like stem borers, leafhoppers and plant hoppers and to find solution for control of pest population by traditional agricultural practices. Oil of Azadirachta indica, Vitex nigundo, Ipomoea carnea, Adhatoda zeylanica and natural surfactant are the main constituents used in the formulations. Larvae of stem borers in the infected stem and hopper damaged part of the plant were selected for the study. A total of six herbal formulations at four different concentrations were sprayed on larvae of stem borers and hopper damaged parts of plants. The developed herbal pesticides have been validated in the field as well as in lab conditions and larval mortality rates were observed. After treatment, the population of pests decreased gradually and the mortality rate of larvae increased. Herbal pesticides focus on providing solutions and relief from various types of insects that cause massive damages to the plants being grown on a farm. These products were made of natural materials that have properties of killing or keeping out pests within the range of the field. The results showed that the extent of growth of these pests was less when compared to control and minimum occurrence of pest attack and Percent Dead Heart (DH) was confirmed in response to herbal formulations. The foremost benefit of this herbal pesticide is managing the Yellow Stem Borer (YSB) pest population and providing healthier cropping systems. Hence it is recommended to use this herbal pesticide for disease free sustainable cultivation of organic rice.

Efficacy of Takumi 20% WG against Rice Stem Borers and Leaf Folder

Insect pests pose major menace to the rice production and amongst these stem borer Scirpophaga incertulas (Walker) and rice leaf folder Cnaphalocrocis medinalis (Guen.) are important and cause enormous yield losses. This study evaluates the efficacy of newer insecticide, Takumi 20WG (flubendiamide 20%) against these, compared with checks, Fame 480SC (flubendiamide 39.35%) and Coragen 18.5SC (chlorantraniliprole 18.5%). The insecticides were applied on economic threshold basis (ETL) for stem borers (2% deadhearts on basmati and 5% deadhearts on non-basmati) and/or leaf folders (10% damaged leaves) in randomized block design. The results revealed that Takumi 20WG @ 125 g/ ha was statistically at par with the checks, Fame 480SC and Coragen 18.5SC but significantly superior to its lower dosages of 100 and 75 g/ ha.

Sustainability and impact assessment of IPM in Basmati rice (Oryza sativa)

Integrated pest management (IPM) strategy has greatly contributed to a progressive commitment for sustainable agriculture in India. Long term studies conducted on validation and promotion of IPM in basmati rice (Oryza sativa L.) in district Gautam Budh Nagar, Uttar Pradesh, India resulted in a gradual enhancement in the area under IPM from 40 ha in 2010 by participation of 25 farmers to 990 ha in 2019 by participation of 654 farmers from 42 villages. Implementation of IPM technology resulted in a significant (P<0.05) reduction in the incidence of yellow stem borer (69.64%), leaf folder (70.9%), brown plant hopper (55.52%), bakane (90.98%) and the population of root-knot nematode (76.8%) over farmers’ practices (FP). It enhanced the population of predatory spiders (84.2%), beneficial soilnematodes (159.27%) and bio-agents, viz. Pseudomonas fluorescens (78.74%) and Trichoderma harzianum (81.34%) over FP. Application of chemical pesticides was reduced to 75.25 g/ha in IPM against 892.93 g/ha in farmers’ practice. The maximum residue level of buprofezin, a widely used insecticide, was recorded below detectable level in paddy grains. Long term studies indicated higher yield (38.0 q/ha) as well as benefit:cost ratio (3.6) in IPM as compared to FP yield (30.5 q/ha) and benefit:cost ratio (2.3) with 58.3% enhancement in net return over FP. Thorough analysis of the data indicated the availability of critical inputs, accessibility of farmers to subject matter specialists through Farmer Field Schools and market for IPM produces as the main factors responsible for sustainability and horizontal spread of IPM in Gautam Budh Nagar.

Silica Amendment Enhances Resistance of Rice to Yellow Stem Borer Scirpophaga Incertulas (Walker) with no Detrimental Effect on Non-target Organism Eisenia fetida (Savigny)

Silica Amendment Enhances Resistance of Rice to Yellow Stem Borer Scirpophaga Incertulas (Walker) with no Detrimental Effect on Non-target Organism Eisenia fetida (Savigny)

Expression and Purification cry1Aa Gene

The cry gene encodes a crystal protein of Bacillus thuringiensis known as Cry toxin, which is toxic to major Lepidopteran insect pest. The effectiveness of Cry toxin against the rice yellow stem borer (YSB, Scirpophaga incertulas Wlk) has been reported. Transgenic Bacillus thuringiensis (Bt) rice has been developed by introducing the fusion gene cry1B::cry1Aa gene driven by the CaMV35S promoter to Javanica rice cv. Rojolele to improve its resistance against rice YSB. Resistance to YSB at a greenhouse and multi-site scales have been conducted and reported. Food and feed safety studies for the release and commercialization of genetically modified crops require a sufficient amount of purified protein sample. Therefore, a strategy to produce Cry1Aa protein in a short time with high productivity needs to be developed. In this study, the cry1Aa gene (1857 bp) was cloned into pRHA-SDM expression vector under the control of the pRHA promoter fused to a 6xHis tag on the C-terminal to produce pRHA-SDM-cry1Aa. The expression host used was Escherichia coli strain NiCo21, and protein purification was performed using IMAC Co2+ on the TALON® matrix. The results showed that the recombinant Cry1Aa protein, approximately 69 kDa, was detected using Western blot performed using anti-rabbit Cry1Aa polyclonal antibody and His detector nickel-NTA conjugated with HRP reporter enzyme. Expression and purification protocols that have been developed can be used to produce Cry1Aa protein which can be utilized for further protein studies.

Main and Ratooned Rice Pest Populations in Lowland Rice Fields, South Sumatra Applied Bioinsecticide from Entomopathogens

The pests that attack each plant phase also varies. The aimed of this study was to compare the main population of rice insect pests and ratooned in lowland rice field in the vegetative, flowering and milk ripening phase. The main bioinsecticide rice sprayed on rice canopy were comes from the entomopathogenic fungal conidia Metarhizium anisopliae, the entomopathogenic bacterium Bacillus thuringiensis, and as a control area without the application of bioinsecticide or synthetic insecticide. The results showed that population of fake white pests (Cnaphalocrosis medinalis) and white leafhoppers pest (Covana spectra) were more prevalent in vegetative phase rice compared to other types of pests such as green leafhoppers (Nephotettix spp.), Brown leafhoppers (Nilaparvata lugens), zig zag leafhoppers. (Recillia dorsalis), white-back leafhoppers (Sogatella furcifera), grasshoppers, mole cricket (Gryllotalpa gryllotalpa), and yellow rice stem borer (Scirpophaga incertulas). The Leptocorisa acuta and green ladybugs (Nezara viridula) began to attack the flowering and milk ripening phase, which was when the rice was aged about 54-68 days after transplanting (dat). Whereas in ratooned rice, the pest population of L. acuta has appeared on the first observation on rice aged 9 days after harvest (dah) until the ratooned rice was aged 58 days after harvesting. The population of pests was higher in land without bioinsecticide application compared to land applied of bioinsecticides. In ratooned rice, the pest population between the land applied with bioinsecticide M. anisopliae and B. thuringiensis was not significantly different from the land applied by B. thuringiensis which was sold in the market.

RICE WHEAT CROPPING SYSTEMS-CONSTRAINTS AND STRATEGIES : A REVIEW

The rice-wheat cropping system (RWCS) in the Indo-Gangetic plains (IGP) of South Asia with the help of Green Revolution in the early 1970’s greatly contributed to India's food self-sufficiency and livelihood of millions of peoplethus, became the country's primary source of food-grain production. However, deterioration of soil health and quality, ground water depletion, water stress, labour shortage, introduction of new weeds and pests particularly Phalaris minor, Scirpophaga incertulas and climate change have all contributed to a major production standstill and deterioration in recent years by which the sustainability of rice wheat cropping system is now at jeopardy. Traditional agronomic practices had various negative implications on the sustainability of rice wheat cropping system with the introduction of HYVs. So, a paradigm shift is required to achieve long-term productivity, sustainability and allow farmers to minimise inputs, optimise yields, enhance profitability, maintain the natural resource base and reduce risk owing to both environmental and economic issues through resource-conserving technologies (RCTs) including zero/minimaltillage, PUSA decomposer, bed planting, crop residue management, mechanical rice transplanter (MRT) and crop diversification. This article focuses some of the issues that need to be addressed in the RWCS in order to achieve the goal of increasing regional productivity and assuring food security while maximising the effective use of natural resources, enhancing rural livelihoods and aiding in poverty alleviation.

A Report on Isolation of mycotoxigenic Fungus fromthe Larval Body Surface of Paddy Pest, Yellow Stem Borer, Scirpophaga incertulas (Walker) (Pyralidae :Lepidoptera)

Yellow stem borer, Scirpophaga incertulas Walker (Lepidopter: Pyralidae) is considered as major paddy pest of global importance. For investigating the role of S.incertulas as mechanical vector of fungal pathogen, an experiment has been carried out. The experiment in field condition was carried out at Central Research Farm, Gayeshpur, Bidhan Chandra Krishi Viswavidyalaya, Nadia, WB during two consecutive kharif seasons of 2018-2019. The infestation by S.incertulas was identified in terms of the incidence of Dead Heart (DH) produced during vegetative stage of paddy crop. A few of them were collected and brought to the Laboratory of Dept. of Zoology, Rabindra Mahavidyalaya, Hooghly, WB. Then the DH stem portion were splitted meridionally, larvae of different age groups were collected from the portion and stored them within a test tube. Few drops of the suspension made from the washing of the body surface of the larvae were inoculated randomly in petri-plates containing PDA media that was incubated at 26 ± 2 °C for 6-7 days. One fungal isolate was obtained in pure culture. Morpho-taxonomy reveals the isolate was Aspergillus flavus. It is thus evicted that apart from paddy crop damage, S. incertulas also acts as a harbourer of potent mycotoxins producing fungal pathogen Aspergillus flavus.