RHS Hemerocallis midge survey

Royal Horticultural Society

Description

The data set consists of records for Hemerocallis gall midge (Contarinia quinquenotata) for Britain and Ireland gathered by the Royal Horticultural Society, from members of the Society and the general public. https://www.rhs.org.uk/advice/profile?pid=742

Data are from 1989 onwards when the Hemerocallis gall midge was first reported as established in the UK. From 1989 to May 2008 all records are via RHS Advisory Service. A majority of records post May 2008 are via the web based form.

Geographic Description

The survey aims for Britain and Ireland coverage, however there is bias towards South East England. This may be partially due to the location of a large proportion of Royal Horticultural Society members. The web form aims to reduce this bias. A majority of records after year 2000 are at 1km or better resolution. Many pre year 2000 records only have 10 km resolution.

Purpose

Data have been collected as part of the surveying work of the Royal Horticultural Society to establish the distribution and spread of the Hemerocallis gall midge, an invasive garden pest of daylilies (Hemerocallis species and cultivars) , which became established in the UK in the late 1980s.

Data quality

Data quality is good, but coverage pre May 2008 is predominantly limited to Royal Horticultural Society members. Records are verified by RHS entomologists, based on samples or descriptions and information (primarily host and description of damage) provided in enquiries to RHS Garden Advice or on the on-line form. Grid references are checked against site names.

Methods

Records of the Hemerocallis gall midge have been collected via the RHS Garden Advice (predominantly from RHS members) and from the general public via an on-line recording for at https://www.rhs.org.uk/advice/profile?pid=742

Citation

Royal Horticultural Society ([Year downloaded]). RHS Hemerocallis midge survey. Occurrence dataset on the NBN Atlas.

Rights

CC-BY-NC

Digitised records