Bio-efficacy of Catharanthus roseus and Artemisia herba alba against Spodoptera littoralis (Boisduval, 1833)

Abstract

The second and fourth instars of the cotton leaf worm Spodoptera littoralis (Boisduval, 1833) were reared on castor bean leaves Ricinus communis (L.) treated with aqueous extracts of two doses, LC25 and LC50, of Catharansus roseus (L.) and Artemisia herba alba (L.), using the dipping method, to evaluate the effect of these botanical extracts on nutritional and percentage antifeeding indices. It was observed that the consumption index was significantly decreased as the dose of the botanical extract from the second to the fourth instar. The approximate digestibility, was significantly decreased at the fourth instar. The food utilization efficiencies, in terms of the conversion of ingested and digested food (ECD) to biomass, were significantly decreased at both botanical extracts. Moreover, the least values of ECD were confined to C. roseus (L.) when compared with A. herba alba (L.). The values of growth rate (GR) were observed to decrease drastically at the two studied doses for both the second and fourth instars.