An integrated approach to the control ofLycoriella solani (Diptera:Sciaridae) during production of the cultivated mushroom(Agaricus bisporus)

Abstract

Individual and combined effects of light-trapping, biological and chemical control on Lycoriella solani (Winnertz) populations in experimental mushroom production cubicles were examined. During three weeks following the introduction of recorded numbers of adult L solani into experimental cubicles, light-traps caught a maximum 74% of flies initially released. However, light-trapping stimulated adult fly activity and immature stages in the growing substrate throughout the experiment. Consequently, no yield improvements, independently or in combination with biological control agents, were recorded. Incorporation of diazinon (25mg AI kg -1 ) to compost following pasteurisation did not significantly reduce subsequent emergence of adult sciarids. Additional drench application of diflubenzuron (1 g AI m 2 ) to the casing layer reduced the number of immature sciarids during the first cropping period by 99% (P<0.001). However, inclusion of chemical insecticides reduced the mushroom yield during this period by 14% (P < 0.001). Introduction of the predatory mite Hypoaspis miles (Berlese) to the compost during its colonisation by mycelium of Agaricus bisporus (Lange) reduced emergence of adult sciarids by 87% (P < 0.05). Later introduction of H miles at the beginning of the case-run period was less effective. Application of the parasitic nematode, Steinernema feltiae (Filipjev (=S bibionis Bovien, after Poinar, 1990)) to the compost during its colonisation by mycelium of A bisporus had no immediate effect on sciarid emergence and provided only limited reduction at later crop stages. Similar application immediately after casing reduced sciarid emergence at first flush by 82% (P<0.05). Irrespective of application time, a formulation of Bacillus thuringiensis (Berliner) var israeliensis had no significant effect on sciarid emergence or mushroom yields at any production stage.