The effect of Tinospora crispa extract against Spodoptera exigua on Spinacia oleracea

Abstract

The emergence of biodegradable pesticides as safe option has reduced the problems that result from the use of synthetic insecticides, thus creating a renewed interest in their development and use in integrated pest management of crops. The objective of this study was to investigate the insecticidal properties of the chloroform (CETC), ethanol (EETC), petroleum ether (PEETC) and ethyl acetate (EAETC) extracts of Tinospora crispa on small mottled millow moth (Spodoptera exigua) infesting spinach (Spinacia oleracea). The stem of the plants used in the experiment were collected from the locality, washed, shade dried, grind into powder and exhaustively extracted with four different solvents; starting with petroleum ether, followed by chloroform, ethanol, and ethyl acetate. A commercial pesticide, Cyperin (CCP) was included in the treatments as a standard check alongside the untreated (control). The experiment was laid out in a randomized complete block design (RCBD) with six treatments and four replicates. The efficacy of the treatments was based on reduction in Spodoptera exigua and percentage reduction in population of the pests. The results showed that EETC and PEETC significantly (p < 0.05) reduced the population of Spodoptera exigua at 61.2% and 51.6% respectively. Though the other two; CETC and EAETC were not significant in reducing the population of the pests, they were better than the control. All the extracts of Tinospora crispa tested were not as effective as the commercial pesticide, Cyperin, CCP (91.5%) in reducing Spodoptera exigua population. Among the tested extracts, EETC was found to be more effective, hence its use by resource poor farmers is recommended in the protection of Spinacia oleracea against the infestation of Spodoptera exigua.