COMPARISON OF THE EFFICACY OF ENTOMOPATHOGENIC NEMATODES FOR THE BIOLOGICAL-CONTROL OF THE MUSHROOM PESTS LYCORIELLA-AURIPILA (SCIARIDAE) AND MEGASELIA-HALTERATA (PHORIDAE)

The efficacy of different species of entomopathogenic nematodes was te sted against larvae of the mushroom phorid Megaselia halterata (Dipter a: Phoridae) and the mushroom sciarid Lycoriella auripila (Diptera: Sc iaridae). Sciarid larvae originating from infestations in casing soil during colonization by Agaricus bisporus were almost completely contro lled by applications of Steinernema feltiae to the casing soil. When l arvae originated from infestations in freshly spawned compost, they co uld be controlled by compost applications halfway through spawn-runnin g and by very early casing treatments. The control of phorids in compo st was maximally 31% when nematodes were mixed within the infested com post at a concentration of 3 x 10(6) nematodes/m(2). Only slightly hig her reduction rates were obtained at higher concentrations. The contro l of phorids was more promising in the infested casing layer in which S. carpocapsae was most successful. At concentrations of 6 and 15 x 10 (6) nematodes/m(2) this species obtained reduction rates of 65 and 73% respectively when it was applied 3 days after the end of the infestat ion period. These concentrations are, however, too high for practical application.