Abstract

Sitophilus zeamais is one of the most important pests of maize in storage causing severe economic damage to the grain. Comparative assessment of the efficacy of Acacia nilotica bark and root powder on the mortality of S. zeamais was conducted at Bayero University, Kano. A. nilotica bark and root was obtained from A. nilotica plant collected from Tofa L.G.A in Kano State and these were shade dried and grounded using pestle and mortar and later sieved using fine mesh to obtained fine particles. Maize grain was collected from Dawanau market. The test insect was obtained from infested maize and was identified morphologically. Twenty gram of disinfested maize were separately introduced into separate Petri dishes and three different amounts of A. nilotica bark and root powder (0.5, 1.0 and 1.5 g) were separately inoculated into these Petri dishes. Control treatment was then set along. All the Petri dishes were vigorously shaken. Ten adult S. zeamais was inoculated into each Petri dish and these were covered with muslin cloth. Each treatment was replicated three times. Mortality of the insect was assessed on daily basis. Highest mortality of the weevil (100%) was observed after 144 h of treating maize grain with the highest treatment level (1.5 g) of both bark and root powders when compared with other treatment levels (0.5 and 1.0 g) which recorded 100% of the weevil only after 168 h of treatment and this result was found to be better than untreated maize grain which does show any sign of insect mortality after 168 h of treatment.

Key words: Maize, Sitophilus zeamais, Acacia nilotica, bark, root, powder.