This study was conducted to assess the attractiveness of growing media containing parboiled rice hulls (PBH) to fungus gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), adults. In comparing commercially prepared PBH with peatmoss (LC1) and pine bark (SB200)-based growing media, it was established that the fungus gnat adults were not specifically attracted to any of the growing media, even those containing PBH, with the mean proportion of fungus gnat adults recovered in the sample compartments ranging from 0.16 to 0.23. Moisture content was more important in terms of fungus gnat adult attractiveness to the growing media. In addition, the volatile constituents of the various growing media were determined using a steam distillation procedure. The component that was present in the highest concentration (39.2%) in the dried PBH as determined by gas chromatography analysis was palmitic acid, a straight-chain C16 fatty acid. S8 (cyclo-octasulfur), a well-known odoriferous component of degraded waste materials, was present at a higher concentration (6.2%) in the RH1 growing medium (80% peatmoss) compared with the other growing media evaluated. The data indicate that PBH, when incorporated in certain growing media, do not attract fungus gnat adults, and as such, greenhouse producers can use PBH as an amendment to growing medium without having to be concerned with the prospect of luring fungus gnat adults and sustaining plant damage.
This study was conducted to assess the repellency of Bounce® original brand fabric softener dryer sheets against fungus gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), adults. For all five experiments conducted under laboratory conditions, fungus gnat adults collected in the sample compartments that included Bounce® original brand fabric softener dryer sheets ranged between 12% and 18% compared with the mean proportion of fungus gnat adults recovered from sample compartments that excluded dryer sheets, ranging in mean proportion from 33% to 48%. Chemical analysis using a steam distillation procedure to isolate volatile constituents found linalool as one of the major volatiles detected in the Bounce® original brand fabric softener dryer sheets. Additional constituents isolated were benzyl acetate, beta-citronellol, and hedione. Based on the results from our study, under laboratory conditions, Bounce® fabric softener dryer sheets do in fact repel B. sp. nr. coprophila adults.