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To determine the longevity of adult bulb scale mites outside narcissus bulbs, and to investigate soil as a potential source of infestation - PH0186

A serious and recurrent pest problem encountered in the commercial production of Narcissus bulbs in the United Kingdom is the infestation of bulb stocks by Steneotarsonemus laticeps Halbert, the Bulb Scale Mite (BSM). The current method for controlling this pest is by one of two standard methods of hot water treatment of the dormant bulbs. Work done at CSL between 1998 and 2000 (6. & 7.) provided conclusive experimental data that validated both standard hot water treatments as fully effective against both eggs and motile stages of the BSM. Despite the routine use of hot water treatments stocks continue to become infested with BSM.

A number of potential routes by which BSM could infest Narcissus stocks and spread, both in the field and in storage have been identified. The purpose of the proposed work is to address a specific gap in our understanding of the biology of BSM, that is, to determine if BSM can be detected in the soil surrounding an infested crop and secondly to determine the longevity of adult BSM in soil. It is intended that the scientific data produced will be used to formulate recommendations for changes to cultural practices that will minimise the possibility of BSM infestations developing in the field on stocks of clean Narcissus bulbs. BSM infestation is jeopardising exports of this crop to the United States. The proposed work is a further step to solving this recurrent problem and thereby safeguarding this important export sector.
June - August 2002

1. To determine if BSM can be detected in the soil surrounding infested plants, and to compare this to the average number found on the plants.

2. To determine under controlled conditions, the longevity of adult BSM when separated from the host plant.

September 2002 - March 2003

3. To determine if a clean Narcissus stock can become infested when planted in soil taken from around a BSM infested narcissus stock.

4. All the experimental data will be subject to statistical analysis and a report written to the required format.

Each objective can be achieved independently. However the results from each are interrelated and are necessary in order to achieve the overall objective.
From past experience, it has sometimes been difficult to obtain suitably infested stocks of Narcissus bulbs to work with.

It is impossible to predict if such a situation is going to occur, as the incidence of BSM fluctuates from year to year.

If such circumstances did occur, the proposed work could not proceed as planned.

Precautionary steps have already been taken. Contact has been made with the Narcissus growers to determine the current availability of BSM infested material, and suitable material will be supplied when available.

Project Documents
• Final Report : final report   (128k)
Time-Scale and Cost
From: 2002

To: 2003

Cost: £10,000
Contractor / Funded Organisations
Central Science Laboratory
Crop Pests              
Pest Control              
Plant health              
Plant Pests and Diseases              
Plants and Animals              
Fields of Study
Plant Health