botanical extracts of tinospora crispa (menispermaceae) and psidium guajava (myrtaceae) against important agricultural polyphagous field pest armyworm, spodoptera litura (fab.) (lepidoptera:noctuidae)

Research Article
Elanchezhiyan. K, Gokulakrishnan. J, Deepa. J and Balu Selvakumar
DOI: 
xxx-xxxx-xxx
Subject: 
Medical
KeyWords: 
Tinospora crispa, Psidium guajava, Spodoptera litura, Antifeedant activity, Larvicidal activity, Ovicidal activity
Abstract: 

The development of integrated pest control programs in controlling the economically important pest, Spodoptera litura (Fab.) has gained increased attention in many parts of the world. The objective of the present study was to evaluate Antifeedant, larvicidal and ovicidal activities of benzene, diethyl ether, ethyl acetate and methanol leaf extract of Tinospora crispa and Psidium guajava against Spodoptera litura (Fab.) (Lepidoptera : Noctuidae),Antifeedant activities of the selected plant extract were studied using leaf disc no-choice method as described by Isman et al. (1990), with slight modifications. Five replicates were maintained for each concentration and the progressive consumption of leaf area by the larvae after 24h was recorded in control and treated discs using leaf area. Twenty five early fourth instar larvae of S. litura was exposed to various concentrations and was assayed in the laboratory by using the protocol of Abbott’s formula (1925); the 24h LC50 values of the Tinospora crispa and Psidium guajava leaf extracts were determined by probit analysis. The ovicidal activity was determined against S. litura to various concentrations were tested under laboratory conditions and the hatch rates were assessed 120 h post treatment. The antifeedant activity of Tinospora crispa and Psidium guajava tested against S. litura fourth instar larvae was determined during a 24 hours test period. All extracts are showed moderate antifeedant activitiy; however, very least antifeedant activity was noted in benzene and significant antifeedant activity was observed in methanol extract.Methanol extract of Tinospora crispa and Psidium guajava showed 100% and 98.38% feeding deterrency against the fourth instar larvae of S. litura at 500ppmconcentration. The LC 50 value of benzene, diethyl ether, ethyl acetate and methanol leaf extracts of Tinospora crispa were 92.64, 96.25, 94.67 and 84.94ppm, respectively and Psidium guajava shows the LC50 values of 144.95, 164.22, 135.64 and 121.86ppm, respectively.The chi-square values are significant at p≤ 0.05 level. Among five solvent extracts, the methanol extract was responsible for strong lethal activity observed against selected pest species. Among two plant solvents tested, Tinospora crispa extracts were found to be most significant ovicidal activity 100% egg mortality (zero hatchability) observed at 160ppm and 200 ppm for Psidium guajava. From the results it can be concluded the crude extract of Tinospora crispa and Psidium guajava were an excellent potential for controlling agricultural pest Spodoptera litura.