1195 Research Article Received: 9 January 2009 Revised: 23 March 2009 Accepted: 18 May 2009 Published online in Wiley Interscience: 26 June 2009 (www.interscience.wiley.com) DOI 10.1002/ps.1809 Biological control of Lycoriella ingenua (Diptera: Sciaridae) in commercial mushroom (Agaricus bisporus) cultivation: a comparison between Hypoaspis miles and Steinernema feltiae Stephen Jess a∗ and Heinrich Schweizer b Abstract BACKGROUND: Mushroom cultivation may be adversely affected by insect pests, including sciarids (Lycoriella spp.), which were previously controlled by application of chemical pesticides. However, owing to food safety and environmental concerns, availability of pesticides for use during mushroom cultivation has diminished. Consequently, it is imperative to investigate alternative control strategies, not reliant on chemical pesticides, which may be used in an integrated pest management system. RESULTS: Application of the predatory mite Hypoaspis miles Berlese to commercial mushroom-growing beds at the beginning of spawn run or just prior to casing (830 mites m −2 ) significantly reduced immature sciarids, Lycoriella ingenua (Dufour), in the growing substrate and also adult activity towards the conclusion of cropping. A trend towards lower sciarid emergence from substrates and reduced adult sciarid activity was observed following the application of Steinernema feltiae (Filipjev) (1.5 × 10 6 nematodes m −2 ) at casing. No significant treatment effects on mushroom yield were observed. However, contamination of the mushroom crop by adult sciarids increased in untreated controls. Application of H. miles required a 12-fold increase in labour when compared with application of S. feltiae. CONCLUSION: Contingent upon the development of an effective application system, H. miles has potential for the biological control of sciarids in commercial mushroom production. c  2009 Society of Chemical Industry Keywords: Agaricus bisporus; mushroom culture; Lycoriella spp.; Sciaridae; Hypoaspis miles; biological control 1 INTRODUCTION Cultivation of the common mushroom Agaricus bisporus (Lange) Imbach is commonly affected by two major classes of insect pest, sciarids and phorids. 1 Sciarids Lycoriella spp. (Diptera: Sciaridae) are a frequent problem, particularly in production systems in which compost is transferred from composting facilities into mushroom- growing houses before it is colonised by the mycelium (spawn running occurs in the mushroom-growing house). 2,3 Subsequent to taxonomic reclassification, two species, Lycoriella ingenua (Dufour) (= L. mali = L. solani) and L. castanescens (Lengersdorf) (= L. auripila) are considered mushroom pests. 4–6 Phorids Megaselia spp. (Diptera: Phoridae) commonly invade compost that is already colonised by the mycelium. 7,8 Phorids are considered to be a seasonal, sporadic pest, with increased importance in production systems where the mushroom mycelia develop in the compost (spawn running occurs at compost manufacture) before it is transferred into the growing houses. 9 The major economic impact of Megasalia halterata has been attributed to adults vectoring fungal pathogens, especially Verticillium spp. 10–12 Previously, insect pest control within mushroom cultivation was relatively uncomplicated, involving the application of chemical pesticides to the compost or casing substrates. 13 However, there are a number of problems associated with chemical control strategies, including insect pest resistance and environmental and food safety issues. This accentuates the need for novel, sustainable approaches to insect pest control during mushroom cultivation that integrate biological, cultural and chemical control strategies. 14–16 Commercial use of the entomopathogenic nematode Stein- ernema feltiae (Filipjev) for biological control of sciarids during mushroom cultivation began in the mid-1990s and is now widely ∗ Correspondence to: Stephen Jess, Applied Plant Science, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK. E-mail: Stephen.Jess@afbini.gov.uk a Applied Plant Science, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK b Department of Applied Plant Science, Queen’s University of Belfast, Agriculture and Food Science Centre, Newforge Lane, Belfast BT9 5PX, UK Pest Manag Sci 2009; 65: 1195–1200 www.soci.org c  2009 Society of Chemical Industry