Biological Activities of Hexane Extract of Piper cubeba Against Rice Weevils and Cowpea Weevils (Coleoptera: Curculionidae)²

Piper cubeba fruit was evaluated for its biological activites to adults of Sitophilus oryzae (L.) and Callosobrunchus maculatus (F.). The hexane extract of berries was toxic (>50% mortality) to both species of insects when applied topically at ≥ 30 μg/insect to S. oryzae and at ≥ 40 μg/insect to C. maculatus. The pulverized berries and its hexane extract, when applied to wheat, were repellent to S. oryzae with the berry powder having greater repellency than the extract. When applied to wheat or black-eyed peas at dosages of ≥ 500 ppm, the hexane extract reduced infestation of S. oyrzae and C. maculatus in these commodities.