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TWO NEW ESSEX GALL-MAKERS.
By EDWARD A. FITCH, F.L.S.
I. ----HORMOMYIA PTARMICAE, VALLOT, ON THE SNEEZE - WORT
(Achillea ptarmica.)
In the summer of 1884, Mr. W. Cole sent me specimens of the
sneeze-wort (Achillea ptarmica), on which the pretty pink galled
flower heads, the result of the attacks of the above-named insect,
were conspicuous. They were found by Mr. English and himself
near the Purlieu Banks, Epping, on July 19th, whilst waiting to
accompany a meeting of the Club to Ongar Park Woods on that
afternoon. I at once determined the species, and bred several of the
GALL OF HORMOMYIA PTARMICAE, VALLOT, ON FLOWER-HEAD OF SNEEZE-WORT.1
gall-gnats on July 21st to 24th, they having pupated within the flower
heads. The fact was recorded in the Club minutes at the time, and
Mr. English preserved one or two of the galls by his well-known
process, but owing to the delay in the publication of our "Pro-
ceedings," the discovery has not yet been publicly announced. On
May 24th, 1887, Mr. Reginald W. Christy again found the beautiful
gall of this gnat at Loughton, and very naturally mistook it at
first for some unknown flower, until a closer examination showed
the plant to be the sneeze-wort. The whole flower-head is deformed
by the presence of the larva into a compact woolly mass, covered
with short pubescence, and surrounded with a tuft of somewhat
1 Mr. Fitch has kindly presented this photo-etching to our journal.—Ed.