Antifeedant Effects of the Black Pepper (Piper guineense: Schum and Thonn) Oil Against Sitophilus zeamais Herbst and Tribolium castaneum Motsch in African Breadfruit Seeds During Storage.
ABSTRACT: This work evaluated the antifeedant effect of Piper guineense (Schum. and Thonn)
Oil against the insect pests, Sitophilus zeamais (Mostch) and Tribolium castaneum (Herbst) in Treculia africana (Decne) seeds. P guineense fruits (200 g) were extracted with 500 ml n-hexane for the spice oil which was dosed at 0,0.25,0.5,0.75 and 1.0% concentrations against 10 adults of either insect during the toxicity study. The piper guineense oil coursed dose-dependent morality of both test insects. Tribolium castaneum was more resistant than Sitophilus zeamais against the spice oil but mortality of both insects increased with exposure time to the oil. In columns’ 70 % filled with Treculia africana seeds, l ml oil concentration after 7 days of exposure caused 50 % kill of T. castaneum and 97 % kill of S. zeamais. Also the l ml spice oil concentration in 1.51 air chamber and exposure time of 48 h caused 72 % kill of T. castaneum and 75 % kill of S. Zeamais in fumigation tests. Thus,piper guineense oil could be used to protect Treculia africana seeds against these pests.
Key words: Antifeedant effect, Piper guineernse oil, Tribolium castaneum, Sitophilus zeamais, Treculia Africana seeds.