Effect of Grain Breakage and Application of Edible Oils to Protect Pear Millet, Pennisetum. glaucum (L.) R Br . Against Infestation by Adult Tribolium. castaneum (Herbst.) {Coleoptera: Tenebrionidae} in Lafia, Nigeria.

AJAYI F. A.

ABSTRACT. The development of Tribolium castaneum (Herb’st.). in five levels of broken grains 0, 20, 40, 60, 80% /20 g pearl millet (Pennisetum glaucum,(L,:) R. Br.), (cv. Gero) grain as well as in milled grain flour was studied over three generations under ambient laboratory conditions (29-390C; 41-5-8% RH)in Lafia (08.33 0N and 0.8,320E). Nasarawa State, Nigeria. Twenty grammes of each level of breakage .and whole meal were infested with five pairs of 3 – to 5 – day old adults for 20 days. Adult”emergence was subsequently recorded for 20 consecutive days following the first adult emergence in each of four treatment replicates, In another experiment, three non-volatile, edible oils of benniseed (Sesamum indicum), olive (Olea europaea) and horseradish (Moringa oleiferay) were evaluated at four rates (10, 20, 30, 40 mg/20 g) to protect broken (20% of 20 g)
millet grains against T. castaneum. Treatments were replicated four in times randomized complete block design. Significantly (P= 0.05) higher- number of adults ’emerged in milled flour than in 100% whole millet grains in each generation. Similarly, significantly fewer adults emerged from whole grains than from broken or milled grains. More adults
emerged during the 1st generation. than ill’ the 2nd and 3rd generations. Olive oil at 40 mg/20 g broken millet grains completely suppressed development of T. castaneum to adult stage over the three generations whereas oil from benniseed and horseradish at the
same rate completely suppressed development in the 2nd and 3rd generations, All the oils protected broken millet grains against adult T. castaneum development when compared with the control.

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