Project background - overview of industry
Mushroom production is a significant component of the horticultural industry. During 2003, the estimated output value of global mushroom production exceeded $7 billion, at world market price. Total European production comprises 3.5 – 4 million tonnes of compost per annum with a value of €450 million. Total annual production of mushrooms in the EU is ca 900,000 tonnes with a farm gate value of ca €3000 million per annum.
Agaricus bisporus (Lange) is the most commonly cultivated edible fungus accounting for approximately 32% of world production (Chang, 1999).
A diversity of mushroom cultivation systems has been developed. This diversity is primarily influenced by geographic and socio-economic factors in the different regions in which mushrooms are produced (Gaze, 1985).
Despite differences in the housing and containers used for cultivation, the principal methods associated with crop production, management, and protection in growing systems are fundamentally similar and comprise a number In the United Kingdom it was estimated that insect pest control, particularly targeted at two Dipteran families, Sciaridae and Phoridae, accounted for 2% of the total farmgate value of the crop (White, 1995). Despite this expenditure, the same author estimated that a further 4% of the yield was lost to insect pests.of discrete phases.
The principal objective of the project was to develop a pest control strategy for the European mushroom production industry, which is less reliant on chemical pesticide inputs. This concept will not only improve competitiveness of the industry in relation to lowering production costs but will increase consumer confidence in relation to chemical residues or insect pollution in the product. Reduction of chemical pesticides will also improve health and safety conditions for employees associated with the mushroom production industry throughout Europe.
The European mushroom production industry comprising compost producers, casing manufacturers, growers and ancillaries affords a labour requirement of 50,000 employees. Total annual mushroom production in the EU is ca 900,000 tonnes with a farm gate value of ca 3000 Million Euros per annum. Insect pest control in commercial mushroom production throughout Europe is an increasing problem and in addition to the ca 60 Million Euros expended on pest control measures, yield losses due to pest attack account for a further ca €123 Million. Withdrawal of insecticides, crop intolerance and the development of pest resistance contributed to reliance on single insecticide ingredients to control each of the major pest species.
Because of the problems associated with pesticides, the primary goal of the project was the reduction of pesticide usage in mushroom cultivation through:
- Increasing the awareness of compost manufacturers and mushroom growers to the potential of physical exclusion and hygiene to reduce pest problems
- Research aimed at improving existing and developing new biological control methods.
Various insect control measures all have advantages and disadvantages:
|Environmentally friendly||Requires attention to technical details of buildings and structures|
|Once implemented little variable costs||High initial capital investment (especially phase III / phase IV compost production)|
|Safe for workers|
|Safe for consumers of mushrooms|
|Environmentally friendly||Somewhat less effective and reliable than chemicals|
|Safe for workers||Optimal application of biological control agents (product handling, optimal application timing) and requires considerable level of growers’ expertise|
|Safe for consumers of mushrooms||Short shelf life of biological control agents|
|Ease of use (users are familiar with it)||Pesticide residues may compromise worker and consumer safety|
|Can be very effective in suppressing pests||Legal requirements for pesticide registrations have led to a limited numbers of products available to mushroom growers|
|Long shelf life of chemicals||Insecticides may cause yield reductions|
|Evolution of resistant pests|
Types of pest
The main types of insect pests of mushrooms are: Sciarids and Phorids
State of the art biological control
The only biological control agent commercially available to mushroom growers is the entomopathogenic nematode Steinernema feltiae. S. feltiae can be very effective in suppressing sciarids. However, it has little effect on phorids and its efficacy against Sciaridae may be unreliable.
Predatory mites, Hypoaspis miles, have proven their efficacy against sciarids in glasshouse crops. Commercial rearing and deployment systems have been developed for these mites.
Preliminary summary of findings
- The predatory mite H. miles, has shown potential as a biological control agent against sciarid pests in mushrooms.
- No deployment method for the mites in mushroom crops has been developed.
- We have not found any evidence of significant interactions (synergism or antagonism) between predatory mites and entomopathogenic nematodes in suppressing sciarids in mushroom compost.
- Laboratory experiments suggest that entomopathogenic nematodes of the genus Heterorhabditis may be more effective than S. feltiae in suppressing phorids in mushroom compost. However, the low levels of observed phorid control suggest that the tested Heterorhabditis spp. may not be a commercially viable control option.
- Further, research is in progress concerning deployment methods of predatory mites against sciarids in mushroom crops and concerning biological control of phorids (with mites and nematodes).
- Jess, S. and Bingham, J.F.W. (2004) Biological control of sciarid and phorid pests of mushroom with predatory mites from the genus Hypoaspis (Acari: Hypoaspidae) and the entomopathogenic nematode Steinernema feltiae. Bulletin of Entomological Research 94, 159-167.
- Jess, S. and Kilpatrick, M. (2000) An integrated approach to the control of Lycoriella solani (Diptera: Sciaridae) during production of the cultivated mushroom (Agaricus bisporus). Pest Management Science 56, 477-485.
- Schweizer, H., S. Jess, M. Kilpatrick. Biological control of Lycoriella ingenua in mushroom crops. Poster presentation, Royal Entomological Society Irish Regional Meeting, Belfast, Northern Ireland, June 17, 2004.
- Schweizer, H., S. Jess, M. Kilpatrick. Hypoaspis miles as biological control agent of Lycoriella ingenua. Poster presentation, 16th International Congress on the Science and Cultivation of Edible and Medicinal Fungi, Miami, FL, USA, March 14-17, 2004.
- Schweizer, H., S. Jess, J. Murray, M. Kilpatrick. Sciarid Control: How do predatory mites compare to Dimilin? Poster presentation, 4th all Ireland mushroom conference & Trade Show, Monaghan, Republic of Ireland, Oct. 16, 2003.