Rhopalomyia florum (Kieffer, 1890)
on Artemisia
Artemisia vulgaris, Belgium, prov. Limbourg, Bocholt, Smeetshof, 29.viii.2019 © Carina Van Steenwinkel: galled, but hardly disfigured flower head
opened head with galled achenes
galled achene; the larva can be hinted
the gall does not consists of a swelling of the achene, but is formed laterally to the aborted achene
another example
in the floret at right even two galls are developing
fully developed larva in opened gall
The larva has no spatula (generic character of Rhopalomyia)
Artemisia vulgaris, Nieuwendam, 15.viii.2011: gall, between two developing fruits and an abortive one
opened gall with larva
parasitised gall (contained a dead chalcid wasp)
Artemisia vulgaris, Nieuwedam; at left a normal fruit, at right a galled one
emptied and vacated gall
host plants
Asteraceae, narrowly monophagous
Artemisia maritima, vulgaris.
gall
The flower heads containing a gall cannot be distinguished from normal heads. The only way to find the galls is by random inspection of ripe flower heads. In my expeprience the galls are not at all rare – tens of galls per plant.
synonyms
Diarthronomyia florum.
notes
see also Rh. magnusi, treated by Buhr as a more or less forgotten species.
references
Buhr (1964b), Dauphin & Aniotsbehere (1997a), Gagné (2010a), Redfern & Shirley (2011a), Roskam (2009a), Roskam & Carbonnelle (2015a), Simova-Tošić, Skuhravá & Skuhravý (2000a), Skuhravá & Skuhravý (1999a), Skuhravá, Skuhravý, Dauphin & Coutin (2005a), Skuhravá, Skuhravý & Meyer (2014a).