Hairs on the caterpillar can cause severe
dermatitis and
How to control Brown Tailed Moths?
Biological control of the Moths themselves is having some success. Exosect (
www.exosect.com) produce biological trapping, monitoring and control products, to control the moths and limit their ability to breed. However, it is more common to deal with the caterpillars as they are more easily identified and it is they that cause the damage. During the autumn and winter months the caterpillar larvae hibernate and develop in ‘tents’ attached to
branches of trees and shrubs. Vegetation containing these tents should be cut and immediately burnt. Each tent contains up to 300 larvae that, once the weather warms, will spread throughout the host plant causing total defoliation and offering the potential for serious health issues to the public in the vicinity.
Operatives working around these infestations must be made aware of the hazards involved and only those with suitable training and the correct PPE should attempt any form of control.
Himalayan Balsam (Impatiens gladulifera)
Himalayan Balsam is the UK’s largest growing annual plant, reaching heights of up to 3m in a matter of weeks. With an attractive flower and an interesting method of seed disposal, the invasive
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breathing difficulties
qualities of this plant are often underestimated. It is not poisonous, nor will it cause structural damage, however, its ability to spread and form ecologically barren monocultures must not be ignored.
Originally imported for its truly desirable flowers and attractive appearance, it has, like so many similar imports, found life in the UK relatively easy and has therefore become more and more widespread.
Traditionally found along river banks due to the ease of spread that exploding seed heads and water transport offer, Himalayan Balsam is now spreading inland and is becoming a common site in highway and rail corridors.
Forming large riparian single species
infestations, river banks become
unstable and liable to
erosion once the vegetation
has died back and during periods of high water flow in autumn and winter months. The dead vegetation washed into the rivers also causes flooding by blocking outlets and restricting flows. Control should be
undertaken throughout the growing season by strimming and spraying using either Glyphosate or 2-4,D Amine. Treatments should be undertaken for up to 3 years and care taken so as to allow for the regeneration of native flora and the exhaustion of the seed bank, all of which helps to prevent future infestations. 2,4-D
Caterpillar larvae hibernate in tents
Amine is a selective herbicide suitable for use on or adjacent to watercourses. Being selective, it allows for the re-growth of grasses and the like. Glyphosate is a total weedkiller and will, therefore, kill all grass and prevent re- naturalisation, so use should be accurate and targeted. As with all applications of herbicides on or adjacent to watercourse, the Environment Agency must be contacted and relevant permissions granted thereafter.
This plant is spreading at an alarming rate through the country and control methods should be thorough and consistent at all times.
Himalayan Balsam has an attractive flower and an interesting method of seed disposal. It can reach heights of 3 metres in a matter of weeks (stem’s a bit ugly though!)
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