GIRI, GOURI SHANKARDEY, AMIT2024-06-222024-06-222023M/ENTO/311/2021-22https://krishikosh.egranth.ac.in/handle/1/5810210756The present study entitled “Bio-ecology and Management of Fall Armyworm, Spodoptera frugiperda S. on Kharif Maize” was conducted at the Research Farm of Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar. The research study focused on the population fluctuation of fall armyworm in relation to biotic and abiotic factors of the environment, biology, biophysical and biochemical bases resistance among genotypes against fall armyworm and management of its thorough some insecticides as seed treatment and foliar spraying. It was observed that the larva was first noticed during 30th SMW (0.20 larvae per plant) followed by adult moth during 31st SMW (2.00 moths per trap). The larval population as well as moth catches per trap reached its first peak during 37th SMW (1.45 larvae per plant and 4.50 moths per trap, respectively) during the vegetative stage and a second peak was observed during 40th SMW (1.35 larvae per plant and 4.50 moths per trap, respectively) during the reproductive stage of crop. Both larvae per plant and moth catches per trap had a positive and significant relationship with morning (r = 0.566* and 0.497*, respectively) and evening (r = 0.570* and 0.529*, respectively) relative humidity and a negative and significant relation with bright sunshine hour (r = -0.509* and -0.564*, respectively). Number of moths per trap had a positive and significant correlation with evaporation (r = 0.574*) while the larvae per plant had a negative correlation with evaporation (r = -0.748**). The predator population in maize ecosystem showed a positive and significant correlation with both trapped moths and larval population. Under laboratory conditions, the total lifecycle was completed within 32.02 and 34.47 days for male and female moth respectivelyu. The incubation period lasts for 2.60 days, larval period for 14.77 days, pupal period for 10.46 days. The lifespan of adult male was 4.18 days whereas for female adult moth it was 6.63 days. Out of 36 genotypes screened, 4 were found resistant, 22 were moderately resistant and 10 were found susceptible. Cob width had a positive and significant correlation (r = 0.335*) whereas number of husk layers had a negative and significant correlation (r = -0.820**) with per cent cob infestation. Trichome density had a negative and significant correlation (r = -0.861**) with per cent plant infestation. Biochemical parameters like total protein (r = 0.852**) and P/C ratio (r = 0.868**) had a positive and significant relation with per cent plant infestation whereas total carbohydrate (r = -0.875**), total phenols (r = -0.868**) and total chlorophyll (r = -0.836**) had a negative and significant relationship with per cent plant infestation. Plots where seeds were treated with Cyantraniliprole 19.8 % + Thiamethoxam 19.8 % @ 6 ml/kg of seed followed by application of Chlorantraniliprole 18. 5 % SC as spray @ 0.4 ml/litre at 4 weeks after germination was found most effective against fall armyworm as the per cent plant infestation (9.21 and 11.54 per cent, respectively), larval population (4.75 and 5.50 larvae per 10 plants, respectively) and mean Davis score (Davis score of 1.70 and 1.83, respectively) was found lowest in both vegetative and reproductive stage in those plots.EnglishThesis