Peptides of microbial origin stand out as one of theprominent tools to elicit plant immunity. These peptides comprise one of thekey strategies of integrated pest management and are considered as candidatesto develop novel biopesticides.  Manyresearch investigations have proved their potential in fending off plantpathogens and were described as sustainable plant protection strategies. Thepresent study was attempted to discover phylogenetic relationships and compareamino acid sequence alignments of various peptide elicitors of microbialorigin. Phylogenetic analysis of 33 microbial peptide elicitors resulted in twoclusters, one cluster contained 19 flagellin sequences, which is furtherdivided into one major (15 peptide sequences) and one (4 peptide sequences)minor subclusters. Further amino acid sequence alignments were carried outbased on the evolutionary relationships among the peptides. The amino acidsequence alignment of flagellin sequences using Clustal W did not present conservativeamino acid sequences except Serine (S), Alanine (A) and Aspartic acid (D).These conserved amino acids (SAxD) that are positioned in the protruding loopmay play a vital role in recognition by plant surface receptors. Alignment ofamino acid sequences of cold shock protein, xylanase, elongation factor andharpin from various sources did not present conservative amino acid sequencesexcept glycine. These investigations lay a theoretical foundation for exploringmany more microbial peptides for inducing plant resistance. 

Keywords: plant immunity,peptide elicitors, microbialpeptides, flagellin, Alignment of amino acid sequences.

The fall armyworm, Spodoptera frugiperda, is a key pest ofmaize crops in tropical and subtropical regions and has developed resistanceagainst synthetic pesticides and Bacillus thuringiensis toxins. Thus,the experiments were designed to evaluate the chemical analysis andinsecticidal efficacy of Vitex negundo against S. frugiperda.Chemical analysis of V. negundo essential oil revealed a total of 36compounds, and the oil contained more monoterpenes (68.16%) than sesquiterpenes(22.21%) and diterpenes (13.56%). For the ovicidal and insecticidal activities,the essential oil was found to be most effective, with a median lethalconcentration (LC50) value of 51.31 µL/mL and 0.29 L/larvae, respectively.Larval antifeedant and growth inhibitory activity of essential oil werepositively correlated (R2 = 0.9645) and (R2 = 0.9727) with oil concentrations,respectively. Therefore, the V. negundo essential oil can be used forthe development of bioinsecticides to control S. frugiperda, a highlyinvasive and polyphagous pest, which will replace chemical pesticides.

Keywords: Bioinsecticide,Essential oil, GC-MS, S. frugiperda, V. negundo

Morphological features are not adequate to accurately categorizedifferent species of the genus Trichoderma. Molecular characters, incombination with morphological characters, are used to identify Trichodermaat the species or subspecies level. The present study was focused oncharacterising Trichoderma asperellum based on morphology and molecularanalysis using genes such as ITS. Light microscopy results showed that Trichodermaasperellum regularly branched and typically paired conidiophores withstraight phialides and globose to subglobose shaped conidia Sequence similarityanalysis with reference T. asperellum isolates available in the NCBIdatabase showed 100 percent nucleotide similarity for ITS4 and ITS5. A dualculture test clearly showed that Trichoderma asperllum inhibited thetested fungal plant pathogen, Fusarium oxysporum f. sp. lycopersici(87.38 percent). Population dynamics of Trichoderma asperellum  incompost were found to be stable until 21 days after mixing.

Keywords: Trichoderma asperellum, Fusarium oxysporum f.splycopersici, Light microscopy populationdynamics

Odontotermes wallonensis is a fungus growing termite species that are abundant inSouth India. Lantana camara leavesextracted with methanol have been found to have repellent and IGR activitiesagainst termites. The extract was also tested on O. wallonensis nymphs and showed significant IGR activity at aconcentration of 1 %.

Entomopathogenic fungi (EPF) are the microorganisms thatspecifically infect and often kill insects and other arthropods. EPF is themost effective biocontrol agent against insects in the natural ecosystem whichcould be an effective alternative to chemical insecticides in bio-intensivepest management. Beauveria bassiana, one of the most prevalentsoil-borne entomopathogens, has virulence on insect pests. The present study isaimed to evaluate the pathogenicity of a native isolate of the entomopathogenicfungus B. bassiana isolated from the soil samples of a cotton field(Kuthukkal) in the Tirunelveli district of Tamil Nadu against Dysdercuscingulatus. Bio-efficacy trials were carried out with six differentconcentrations viz., 4.6 × 10³,1.5× 10⁴, 5.0 × 10⁵, 2.7 × 10⁶, 3.2 × 10⁷,and 2.8 x 10⁸ (spores/mL) in all the five nymphal instars and theadults of D. cingulatus. A 100% mortality was observed in higherconcentrations 2.8 x 10⁸ (spores/mL) at 120hrs after treatment. The resultsof the present study show that the isolate seems to be highly promising in thepest management of D. cingulatus.

Keywords: Entomopathogenicfungi, Beauveria bassiana, Dysdercus cingulatus, biocontrol