Work

Perforation index assessment of cowpea seeds against cowpea bruchid, Callosobruchus maculatus (Fabricius) [Coleoptera: Chrysomelidae], infestation using Piper guineense

Year: 2020

Type: article

Abstract: Background Powders and extracts ofPiper guineenseseeds and leaves were assessed for insecticidal activities againstCallosobruchus maculatusin the laboratory at temperature and relative humidity of 29.6 °C and 75.9%, respectively. Bioactive compounds inP.guineenseleaves 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 ofP.guineenseseed were more toxic than seed powder.Piper guineenseseed extract caused 87.5% adult mortality ofC.maculatuswhile leaf extract caused 70.0% adult mortality within 24 h of infestation at concentration of 1%. Progeny development ofC.maculatuswas completely inhibited in cowpea treated with 2% and 3% leaf and seed extracts ofP.guineense. β-Pinene was the most abundant active compound inP.guineenseseed (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 thatP.guineenseseed powder and extracts were more effective than leaf powder and extract. Utilization of plant products as alternative to synthetic insecticides in protecting cowpea seeds againstC.maculatusshould be encouraged for enhanced food safety and security.Piper guineenseis used as spice and medicine and interestingly safe for human use.

Source: The Journal of Basic and Applied Zoology

DOI: 10.1186/s41936-020-00195-7

Authors: Kayode David Ileke, Jacobs Mobolade Adesina, Luke Chinaru Nwosu, Abimbola Olagunju

Institutions: Federal University of Technology, Institute of Bio-Resources and Sustainable Development, Rufus Giwa Polytechnic, University of Port Harcourt, Adekunle Ajasin University

Language: English

Topic: Insect Pest Control Strategies

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: diamond

Funder: Adekunle Ajasin University