Background Powders and extracts of Piper guineense seeds and leaves were assessed for insecticidal activities against Callosobruchus maculatus in the laboratory at temperature and relative humidity of 29.6 °C and 75.9%, respectively. Bioactive compounds in P . guineense leaves and seeds were also investigated. The powders were tested at rates 1.0, 2.0 and 4.0 g/20 g cowpea seeds while extracts were tested at 1.0, 2.0 and 3.0%. Results Results of contact toxicity assay of the seed powder caused 100% adult mortality at 96 h post-treatment period whereas leaf powder evoked 90% adult mortality within the same period at concentration of 1.0 g/20 g cowpea seeds. Low adult emergence was observed on cowpea seeds treated with 1 g of seed powder with percentage adult emergence of 10.0% and inhibition rate (IR) of 97.5%. Beetle Perforation Index (BPI) obtained from treated cowpea seeds was significantly different ( P < 0.05) from BPI of untreated seeds. Extracts of P . guineense seed were more toxic than seed powder. Piper guineense seed extract caused 87.5% adult mortality of C . maculatus while leaf extract caused 70.0% adult mortality within 24 h of infestation at concentration of 1%. Progeny development of C . maculatus was completely inhibited in cowpea treated with 2% and 3% leaf and seed extracts of P . guineense . β-Pinene was the most abundant active compound in P . guineense seed (55.6%) and leaf (48.4%). β-Phellandrene occurred 38.2% in seeds while Ocimene had the least value of 0.2% in seed and 0.5% in leaf. Conclusion The study showed that P . guineense seed powder and extracts were more effective than leaf powder and extract. Utilization of plant products as alternative to synthetic insecticides in protecting cowpea seeds against C . maculatus should be encouraged for enhanced food safety and security. Piper guineense is used as spice and medicine and interestingly safe for human use.

中文翻译：

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豇豆种子对豇豆、Callosobruchus maculatus (Fabricius) [鞘翅目：Chrysomelidae]、使用 Piper guineense 侵染的穿孔指数评估

背景 在实验室中，分别在 29.6 °C 和 75.9% 的温度和相对湿度下，评估了蒺藜种子和叶子的粉末和提取物对 Callosobruchus maculatus 的杀虫活性。P 中的生物活性化合物。几内亚叶和种子也进行了研究。粉末以 1.0、2.0 和 4.0 克/20 克豇豆种子的比例进行测试，而提取物以 1.0、2.0 和 3.0% 的比例进行测试。结果 种子粉的接触毒性试验结果在处理后 96 小时导致 100% 的成虫死亡率，而在同一时期内，当浓度为 1.0 g/20 g 豇豆种子时，叶粉引起 90% 的成虫死亡率。在用 1 g 种子粉处理的豇豆种子上观察到成虫率低，成虫率达 10.0%，抑制率 (IR) 为 97.5%。从处理过的豇豆种子获得的甲虫穿孔指数 (BPI) 与未经处理的种子的 BPI 显着不同 ( P < 0.05)。P 的提取物。几内亚种子比种子粉毒性更大。Piper guineense 种子提取物导致 87.5% 的 C 成年死亡率。maculatus 而叶提取物在 1% 的浓度下在侵染后 24 小时内导致 70.0% 的成虫死亡率。C 的后代发育。用 2% 和 3% 的豇豆叶和种子提取物处理的豇豆中完全抑制了 maculatus。吉尼斯 β-蒎烯是磷中含量最丰富的活性化合物。几内亚种子 (55.6%) 和叶子 (48.4%)。β-水芹烯在种子中的含量为 38.2%，而罗勒烯在种子中的含量最低，为 0.2%，叶中的含量为 0.5%。结论 研究表明，P . guineense 种子粉和提取物比叶粉和提取物更有效。利用植物产品替代合成杀虫剂保护豇豆种子免受 C . 应鼓励黄斑病以加强食品安全和保障。Piper guineense 被用作香料和药物，并且对人类使用是安全的。