Rhopalomyia florum (Kieffer, 1890)

on Artemisia

Rhopalomyia florum: gall on Artemisia vulgaris

Artemisia vulgaris, Belgium, prov. Limbourg, Bocholt, Smeetshof, 29.viii.2019 © Carina Van Steenwinkel: galled, but hardly disfigured flower head

Rhopalomyia florum: galls on Artemisia vulgaris

opened head with galled achenes

Rhopalomyia florum: gall on Artemisia vulgaris

galled achene; the larva can be hinted

Rhopalomyia florum: galls on Artemisia vulgaris

the gall does not consists of a swelling of the achene, but is formed laterally to the aborted achene

Rhopalomyia florum: galls on Artemisia vulgaris

another example

Rhopalomyia florum: galls on Artemisia vulgaris

in the floret at right even two galls are developing

Rhopalomyia florum: larva

fully developed larva in opened gall

Rhopalomyia florum: larva

The larva has no spatula (generic character of Rhopalomyia)

Rhopalomyia florum gall

Artemisia vulgaris, Nieuwendam, 15.viii.2011: gall, between two developing fruits and an abortive one

Rhopalomyia florum larva

opened gall with larva

Rhopalomyia florum parasitised gall

parasitised gall (contained a dead chalcid wasp)

Rhopalomyia florum gall

Artemisia vulgaris, Nieuwedam; at left a normal fruit, at right a galled one

Rhopalomyia florum gall

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).

mod 12.ix.2019