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Surveys on the spread of non-native garden pests

Lead scientist
Dr Andrew Salisbury, RHS
Partners
UK gardeners and the National Biodiversity Network (NBN)
Start date
2008
Keywords

Lily beetle, red lily beetle, scarlet lily beetle, Lilioceris lilii, Hemerocallis gall midge, daylily gall midge, Contarinia quinquenotata, berberis sawfly, Arge berberidis, Rosemary beetle, Chrysolina americana, invasive non natives, alien pests, web survey, citizen science.

Benefits to gardeners

The project is providing information on the distribution and host range of four non-native invasive garden pests, improving knowledge of these insects and the advice provided by the RHS. These pests are lily beetle (Lilioceris lilii), rosemary beetle (Chrysolina americana), hemerocallis (day lily) gall midge (Contarinia quinquenotata) and berberis sawfly (Arge berberidis).

The information gathered means that a more accurate assessment can be made of the threat that these invasive non-natives pose to gardens and the wider environment. The UK government needs access to up-to-date information on the distribution of non-native species to underpin policy decisions (defra et al 2008).

There are the additional benefits of engaging with current and future RHS members and the general public ('citizen science'), informing policy and contributing to the scientific community worldwide.
 

The problem

The threat to biodiversity from invasive non-native species is considered secondary only to climate change (defra et al 2008). For example lily beetle has the potential to threaten native snakes-head fritillary populations (Fritillaria meleagris) and the berberis sawfly can defoliate native Berberis vulgaris, threatening the rare barberry carpet moth (Pareulype berberata). The barberry carpet is a UK Biodiversity Action Plan (BAP) species, whose caterpillars also feed on the foliage of B. vulgaris.

Approach

Historically the RHS has collected data on the distribution of invasive garden pests through pest enquiries sent to the RHS members’ advisory service. For example, detailed information has been gained in this way on the establishment, rate of spread and host range of lily beetle (Lilioceris lilii) and rosemary beetle (Chrysolina americana).

A more proactive approach for four pests has been developed using internet-based surveysthat enable gardeners to submit their own records. Information submitted via the RHS website is analysed and maps, web pages and advice updated accordingly on an annual basis. This information is shared with the National Biodiversity Network (NBN).

Across the four surveys over 9000 records had been received and submitted to the NBN by the beginning of 2012.

The RHS is keen for data it holds to be used and would like to collaborate in research. Contact advisory_entomology@rhs.org.uk if you would like to use RHS data for research.
 

Further information

Lily beetle survey page

Berberis sawfly survey page

Hemerocallis gall midge survey page

Rosemary beetle survey page

National Biodiversity Network (NBN)

References

Defra, Government WA & Government TS (2008) The Invasive Non-Native Species Framework Strategy for Great Britain. Protecting our natural heritage from invasive species, London.

Advisory information

Rosemary beetle

Red lily beetle

Berberis sawfly

Hemerocallis gall midge

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