Volume 12 Part 2 Article 87
Title: Variation in Resistance to Diazinon by the Mushroom Sciarid Lycoriella auripila
Authors: P.F. White and D.A. Gribben
In the U.K. 500 commercial mushroom growers produce 110,000 tonnes of mushrooms annually with a gate value of £ 130,000,000 (1986), making it the most valuable single protected crop accounting for about 50% of the value of the protected crops industry. Within the mushroom industry, it is estimated that produce to the value of £ 5,000,000 is lost due to pest attacks and approximately £ 1,300,000 is being spent in efforts to control them.
The most serious pest problems in commercial production of Agaricus spp., throughout the world, are posed by three Families within the Order Diptera, namely the Sciandae, Phondae and Cecidomyndae.
A species of Sciandae – Lyconella aunpila (Winnertz) – is, at the present time, the major mushroom pest in the U.K. It is capable of damaging the crop at all stages of post-Phase II production and causing losses in both total and marketable yield (White, 1986a,b; Fletcher, White and Gaze, 1986). Twelve years ago Binns (1976) reported that sciand populations from the Mushroom Unit at the Institute of Horticultural Research – Littlehampton (GCRI) and from a commercial farm near London were resistant to two organophosphorus (OP) insecticides – chlorfenvinphos and pinmiphos-ethyl – commonly used at that time as casing incorporation treatments. Fortuitously, the chitin-inhibitor, diflubenzuron, was being developed for sciarid control at about the same time and, once shown to be effective against these resistant strains of sciand, was rapidly taken up by the mushroom industry to become the standard control measure for this pest.
Apart from the two populations tested by Binns (1976), no further attempts were made to discover the extent and degree of OP-resistance by sciarids in the U.K. In addition, the normal control measure for the other major mushroom pest in the U.K., the phorid Megaselia halterata, is the use of another OP, diazinon, in the compost at spawning. Thus, if a commercial farm is affected by both of these pests (a common occurrence) the sciand population is subjected to both diazinon and diflubenzuron treatment.
The following paper, therefore, sets out to examine the extent and distribution of resistance to diazinon by populations of sciarids obtained from various commercial mushroom farms throughout England during 1986.Please login to download the PDF for this proceeding.