Chemical composition of essential oil in Piper nigrum from Nigeria and its bioactivity against stored-grain insects

Experiments were carried out on the essential oil (EO) and its bio-efficacy against rice weevil (Sitophilus oryzae) and cowpea seed beetle (Callosbruchus maculatus). The EO from Piper nigrum was extracted by using steam distillation. Thirty-nine components were identified by using GC-MS, and the major components are linalool (21.73%), γ-bisabolene (8.75%), and β-caryophyllene (7.35%). The insects were exposed to the EO. At p < 0.05, the efficacy depends on the dose and time of exposure. S. oryzae is more resistant to the oil than C. maculates. The essential oil of P. nigrum may be used as a botanical insecticide against insect pests.