Assessment of short-term mortality of granary weevil, Sitophilus granarius (Coleoptera: Curculionidae) triggered by different microwave irradiation powers

Abstract

The insecticidal efficacy of microwave irradiation against the at 12, 24, 48 and 72 h following exposure to microwave irradiations (100, 300 W) and the progeny production was assessed 45 days later. Linearly increasing irradiation power range (100, 200 and 300 W) was set up for determining mortality tendency. An increase of insect mortality caused by higher irradiation period and times elapsed after treatment has become evident commencing from 12 h after the treatment, which has significantly decreased at later elapsed time after treatment. The irradiation periods inducing the highest mortality at the examined powers were at 10 min and at 100 W power (72 h: 64.93%) and at 4.5 min. and at 300 W power (12 h: 87.01). In addition, a complete suppression of progeny production was achieved by 4.5 min treatment at 300 W power. Lognormal-type mortality process was caused by the linearly increased irradiation range. The properly chosen microwave irradiation can be used for management of Sitophilus granarius larval and adult developmental stages. This treatment could provide an effective and friendly environmental treatment technique in Integrated Pest Management (IPM) program.