Ratnakala

Title : Prospects of using entomopathogenic nematodes against invasive fall armyworm, Spodoptera frugiperda (J. E. Smith)

Abstract:

Invasion of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) to India was reported for the first time from Karnataka. Ever since its infestation spread in the entire country covering major maize growing lands including sweet corn and baby corn. Entomopathogenic nematodes delineate potential biological control agents for the management of S. frugiperda: In the study, the virulence of Heterorhabditis indica (Poinar) and Steinernema carpocapsae (Weiser) against all the developmental stages of S. frugiperda was evaluated.

Results: The results revealed that both the tested EPNs had a high rate of ovicidal, larvicidal, and pupicidal activities against the targeted pest. Mortality of S. frugiperda eggs ranged between 66.67-100 %. Exposure of EPNs at 100, 250, and 500 IJs resulted in larval mortality of 20.00 to 100.00 % in 4^th instar larvae, 33.33–100.00 % in 5^th instar larvae and 23.33-100% in 6^th instar larvae. In the case of pupae, the mortality recorded was 30.00 to 71.67 % and 43.33 to 100 % of the emerged adults had deformed wings and died within 48 h of emergence. The mortality rate of the pest was a function of life stage, EPN concentration and incubation period. The invasion efficiency and reproduction assays of EPNs revealed that H. indica had the higher invasion efficiency (11.00±0.3 to 24.93± 0.6 %) and reproduction rates (8226.5±65.2 to 99561±565.4 IJs/ larva) compared to S. carpocapsae with invasion efficiency (10.67 ± 0.3 to 21.00±0.6%) and reproduction rate (6596.7±162.1 to 95436.67±394.0 IJs/ larva) in the larvae. In the pupae the penetration and reproduction rates of 5.00±0.3 to 13.93±0.6% and 4392.67±22.6 to 31606.33±264.7 IJs/ pupa respectively were recorded, while the EPNs also reproduced in the adult cadavers of S. frugiperda producing 5462.33±145.2 to 15447.33±285.7 IJs/ adult.

Conclusions: The study demonstrated that both the EPN species showed high Puissance of bio-control agent against S. frugiperda, therewith having the potential to be used in the successful management of the pest.

• The audience will learn the potential use of Entomopathogenic nematodes in insect pest management
• Bioefficacy of the EONs against different stages of the fall armyworm
• Use of a cost-effective yet eco-friendly approach of EPNs application
• Management of invasive fall armyworm using EPNs

Biography:

Ms. Ratnakala underwnt undergraduation studies at University of Agricultural sciences dharwad during 2016-20. Then she pursued master's degree in agricultural Entomology from University of Agricultural and Horticultural Sciences shivamogga. Currently she is pursuing her PhD degree in Entomology from University of Agricultural sciences dharwad.