Vibrations suppress larval development in the dark-winged fungus gnat Lycoriella ingenua (Diptera: Sciaridae)

Abstract

Many insects use their sensory systems in various ways to detect substrate-borne vibrations for survival. This sensitivity can be utilized for pest management using vibrations as a sustainable non-chemical method. Recently, increases in ambient noise associated with human activity—known as anthropogenic noise—can also produce vibrations that may lead to unexpected reactions in insects. However, little is known about the impact of vibrations on individual development in insects. Furthermore, previous studies of anthropogenic noise have been dominated by airborne sound, and studies of substrate-borne vibration are limited. Here, we investigated the effects of vibrations on egg hatching and larval development in the dark-winged fungus gnat, Lycoriella ingenua (Dufour, 1839) (Diptera: Sciaridae), which is a major pest of commercial mushrooms worldwide. Vibration at a frequency of 3000, 1000, 800, or 100 Hz with low- or high-acceleration treatment suppressed the emergence rate to almost zero. Emergence rate suppression was caused by increased early and late larval mortality at 3000 Hz vibration, whereas it was caused by increased early larval mortality at 100 Hz vibration, suggesting that the impact varied with the frequency. Hatch rate was suppressed only at 3000 Hz and with low acceleration, indicating that the impact of vibration was much higher on emergence rate than on hatch rate. Our findings will help to develop vibrational pest management and mushroom cultivation, and to estimate the previously unexplored impacts of anthropogenic-noise-related vibration on insects.