Morphological and molecular identification of an invasive insect pest, fall army worm, Spodoptera frugiperda occurring on sugarcane in Andhra Pradesh, India
Bhavani B, Chandra Sekhar V, Kishore Varma P, Bharatha Lakshmi M, Jamuna P and Swapna B
An invasive pest, fall army worm (FAW), Spodoptera frugiperda was noticed on 20 to 60 days old sugarcane crop (5-20%) at Regional Agricultural Research Station, Anakapalle and in some isolated pockets of Andhra Pradesh, India during February- March, 2019. Other than sugarcane, it was also reported on maize, sorghum, bajra and ragi in different districts of Andhra Pradesh during August-November, 2018. Early instars feed on sugarcane leaves scraping the chlorophyll leaving silvery transparent membrane. Later instars causing windows on leaves, leaving behind faecal pellets in whorls. In severely infested plants, large quantities of frass mass pellets were seen with mature larvae hidden in the whorls. FAW total life cycle ranged from 30-36 days on sugarcane during March-April months. In the present investigation both morphological and molecular characterization were studied for S. frugiperda. For molecular identification, partial amplification of mitochondrial DNA COI gene was done using specific primers viz., JM 76/JM 77 and confirmed its identity as S. frugiperda using BLAST programme of NCBI database. This confirms first report of S. frugiperda incidence on sugarcane from Andhra Pradesh, India. Further, a phylogenetic tree was constructed with very closely related S. frugiperda sequences from the NCBI database and it reveals that S. frugiperda has close resemblance with ‘corn’ strain. The population from Anakapalle has formed a separate clade in dendrogram and it has showed 99.75% resemblance with Mexico colony haplotypes of ‘C’ strain.
Bhavani B, Chandra Sekhar V, Kishore Varma P, Bharatha Lakshmi M, Jamuna P and Swapna B. Morphological and molecular identification of an invasive insect pest, fall army worm, Spodoptera frugiperda occurring on sugarcane in Andhra Pradesh, India. 2019; 7(4): 12-18.