64 AN ACCOUNT OF BRITISH FLIES. 
with red markings. Wings dusky white and hairy; apex of the 
halteres also dusky white. Costal vein dark brown, second longitu- 
dinal vein straight ends at some little distance from the tip of the 
wing. ‘The transverse veinlet in g is before the middle of first 
longitudinal vein; in the ¢ af the middle of first longitudinal. 
Antenne yellowish-white, composed of 15 Sct Silvery hairs on 
the legs. 
These willow-flies only live twenty-four hours, and are found in 
many parts of Europe besides England. They are subject to several 
parasites, including Z7yzdymus salicis, Torymus salicicola, and Eury- 
tomus (Sp. ?). 
Cecidomyia nigra, Mg.* 
This species is placed amongst the reputed British Cecids in 
Verrall’s list. It has, however, been found in England in recent 
years, and can fairly be entered as a British insect. The Rev. E. N. 
Bloomfield, of Guestling, showed me many of the larvze of this species 
a few years ago. They were remarkable for their saltatory powers. 
They affect the cores of young pears, destroying the pulp, and causing 
the pears, when only partly formed, to drop off. They form blackened 
tunnels from their cavity in the pulp in all directions. Mr. Bloom- 
field found they used the “ Marie Louise” pears for their nurse, 
whilst we have found similar larve in the ‘‘William” pear. They 
are yellowish-white in colour, and, according to Mr. Inchbald, 
pupate in the soil, spinning a p#péry cocoon enclosed in a case of 
earth,t and also according to cee This possibly belongs — 
to the sub-genus Dzp/osts. 
C. brassicea, Wtz.t=C. napi, Lw. 
The larve of this species live in the flowers and leaves of the 
cabbage (B. oleracea) and in the pods of apus and Chetranthus, 
Walker§ says as many as fifty to sixty live in one pod of the rape (ZB. 
rapa). The turnip (zapus) suffers largely from this larva in parts of 
England. They appear in May and June, and change in the earth. 
Imago black. Abdomen red, black bands on the dorsum. Palpi 
white, antennz 15-jointed, with long whorls of hairs in the ¢ ; joints 
petiolate. In the 9 the joints are sessile and the hairs much 
shorter, antennz not half the length of the body. Base of the halteres 
rose-coloured. Wings limpid, with black veins. First longitudinal near 
* Meigen, ‘‘ Systematische Beschreibung der bekannten europaischen Zweiflii- 
geligen Insekten.” Aachen, 1818, pl. iii., fig. 11. 
t Entomologist, 1886, p. 35. 
~ Lin. Ent., p. 231, Winnertz, Laboulbéne, Ann. Ent. Soc., Fr. 1857. 
§ Ins. Brit., vol.-iii., p. 84. 
