Isolation, characterization and insecticidal effects of six wild mushroom species against maize weevil, Sitophilus zeamais Motschulsky 1855 (Coleoptera: Curculionidae)
摘要
Mushrooms have gained wide acceptance as food and medicinal supplements, yet information on their potential biotechnological application as a bioinsecticide is relatively limited. Six species of wild mushrooms were collected locally and characterised using morphological features, microscopy, and molecular methods. A mixture of acetonitrile, acetic acid and water (80:1:19 v/v/v) was used as the solvent for extraction of the mushroom species. The fumigant activity of the extracts against maize weevil, Sitophilus zeamais Motschulsky 1855 (Coleoptera: Curculionidae) was determined using 26.67, 53.33 and 80.00 µL/L air, dichlorvos and the solvent served as positive and negative controls, respectively. The repellency of the extracts was evaluated using 0.31, 0.62 and 0.93 µL/cm2, while the solvent served as the control. The mushroom species were identified as Schizophyllum species, Phellinus species, Trametes versicolor, Oudemansiella australis, Collybia hariolorum and Hypocrea species. Hypocrea species extract had the highest fumigant toxicity (96.0%), which was at par with C. hariolorum (94,33%), and T. versicolor (90.67%) all applied at 80.00 µl/L air, which were at par with dichlorvos (100.00%) at 60 min after treatment (MAT). The mushroom extracts showed a significant degree of repellency against S. zeamais in the following order Phellinus species, Collybia hariolorum, Hypocrea species, Oudemansiella australis, Schizophyllum species, and Trametes versicolor. Phellinus sp, Collybia hariolorum, Hypocrea sp and Oudemansiella australis showed comparative superior properties against S. zeamais than the other species; therefore, they can be explored as sources of biopesticides against the pest.