author(s)
Sherifat A Aboaba, Idowu O Okunlola and Mobolade D Akinbuluma

abstract
This present work aims to study for the first time the chemical composition and evaluate insecticidal effects of essential oils of Cardiospermum grandiflorum, against Sitophillus zeamais, an insect pest of stored maize seeds as alternatives to synthetic pesticides. The essential oils were obtained from the leaf, stem and root of Cardiospermum grandiflorum using hydro distillation, and the oils were analysed by Gas Chromatography-Mass Spectrometry (GC-MS). Insecticidal analysis was carried at ambient temperature of 27 ± 2 ⁰C and relative humidity of 78 ± 5% using adult Sitophillus zeamais. Parameters including mortality and viability of seeds were assessed and all data were analysed using Analysis of Variance (ANOVA), the differences were compared at 0.05 significant level using Least Significant Difference (L.S.D). The percentage yield of essential oils from the leaf, stem and root were 0.37%, 0.42% and 0.33% respectively. A total of 27, 14 and 8 constituents were characterised in the leaf, stem and root with isogermacrene (14.05%), caryophyllene oxide (29.49%) and α-octadecene (49.36%) being predominant compounds in the essential oils respectively. Insecticidal activities of the essential oils of Cardiospermum grandiflorum leaf, stem and root on Sitophillus zeamais showed that 25.00% concentration was most toxic at 12 - 24 hour post treatment. All the treated maize seeds were viable when treated with the essential oils from the leaf, stem and the root. The essential oils from the leaf, stem and root of Cardiospermum grandiflorum had significant mortality effect on Sitophillus zeamais, this suggests that the essential oils could render insecticidal activity in the control of Sitophillus zeamais and related stored seed products.