Pests of Oyster Mushroom (Pleurotus Ostreatus) in Western Kenya

Abstract

Productivity of oyster mushrooms has been hampered by pests but little is known about them. Pest spectrum of oyster mushroom on farms in western Kenya was investigated. Oyster mushroom Pleurotus ostreatus was established at three sites namely; old mushroom farm, new mushroom farm and on-station during short rains, dry season and long rains in Butere constituency Kakamega County between September 2012 and August 2013. Pests were sampled weekly and identified using taxonomic keys at the National Museums of Kenya. The mite Pygmephorus spp. (Acaridae) and dipterans Megaselia scalaris (Phoridae), Bradysia spp. (Sciaridae), Culicoides spp. (Ceratopogonidae) and Anatrichus spp. (Chloropidae) were identified. All the other pests except Bradysia spp. were reported at the three sites across the three seasons. The incidences of all these pests were reported only during the incubation phase of oyster mushroom. Incidences of M. scalaris were 42% of the total four pests that were sampled followed by Culicoides spp. at 33% with that of Pygmephorus spp. being 17% while that of Anatrichus spp. being 8%. Pygmephorus spp. was vectored by M. scalaris hence the incidence of Pygmephorus spp. depended on M. scalaris. These two pests were found to be pests of economic importance in oyster mushroom production causing both direct and indirect damage on oyster mushroom. The old mushroom farm reported high incidences of these two pests, with the new mushroom farm recording the lowest incidences. Equally the short rains recorded high incidences these two pests with long rains recording low incidences. Although Bradysia spp. has been considered a major mushroom pest, it was found to be a minor in the area of study.