Species Account for Merzomyia westermanni
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Essex RDB: Listed
Additional Phenology Data
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Taxonomic group: flies (other) (Diptera: other groups) - County data
The species is scarce, with nearly all Essex records in the south of the county. Nationally it has a strongly southeastern distribution with almost all records south of a line between the Wash and Severn map in Clemons (2004). It is a gallfly, whose larvae form a gall in the flower head of Ragwort Senecio, especially Hoary Ragwort S. erucifolius. Infected plants are usually obvious because the swelling forces up groups of pappus hairs. References