Potential for use of garlic oil to control Lycoriella ingenua (Diptera: Sciaridae) and Megaselia halterata (Diptera: Phoridae) in commercial mushroom production

The repellent effects of garlic oil to Lycoriella ingenua and Megaselia halterata were examined in static olfactometers. In a choice between treated and control glass beads, adult female M. halterata were repelled by garlic solutions at concentration levels as low as 0.1% (v/v). When provided with a choice between compost treated with a range of garlic concentrations (0.1-20%) adult female M. halterata demonstrated a clear preference for untreated compost. In contrast, olfactometer studies involving L. ingenua females were inconsistent. For L. ingenua, the highest concentration of garlic oil (20%) significantly reduced subsequent adult emergence from treated spawned compost. With increasing concentrations of garlic oil, M. halterata emergence was progressively reduced. For both pest species, application of garlic oil post-oviposition had no significant effect on subsequent survival of immature life stages and surprisingly enhanced final emergence.