Maize is one of the most important and oldest cultivated cereals. However a wide range of insect pests attack maize both in the field and storage. Lime was collected from Dora farm House, Kaduna State and was identified in the Herbarium of Department of Pharmacognocy, Ahmadu Bello University, Zaria. The unripe, peeled and dried lime was grounded into powder using pestle and mortar. The oil was extracted by soxhlet extraction method. Sitophilus zeamaise was obtained from naturally infested maize grains obtained from Rimi market, Kano State. The insect was identified based on morphological appearance. The Maize used for bioassay was disinfested in a deep freezer for 96 h and later air-dried in the laboratory under the ambient conditions (32±0.64°C and 68±3% RH) and the moisture content was determined. Twenty five gram of the sample was weighed into separate containers. Four concentrations of the oil (1.5, 2.0, 2.5 and 3.0 mL) were inoculated separately into these containers. These concentrations correspond to (6.0, 8.0, 10.0 and 12.0% v/w). Five insects (day old) were separately inoculated into these containers and covered with muslin cloth. Each treatment was replicated, arranged in a Completely Randomized Design (CRD). The result indicated that the mortality of the insect was dose dependant where the higher concentration used recorded the highest mortality (100%) after 72 h of treatment which is significantly higher (p<0.005) than untreated control (0%). Lime peel oil is effective in the protection of maize against weevil Sitophilus zeamaise.
N. Abdullahi, A. Kabir and M. Yushau, 2011. Studies on the Efficacy of Lime Peel Oil in Protecting Stored Maize against Adult Maize Weevils (Sitophilus zeamais: Motschulsky). Journal of Entomology, 8: 398-403.