TURNIP AND CABBAGE GNAT MIDGE. ices: 
in portions, I insert above a figure of another species of Cecidomyia 
and its larva, as a guide to the general appearance; and in the case 
of the maggot (with the exception of the anchor-process represented 
being more deeply notched than that of the species under observation ) 
it gives a very fair representation. 
The perfect insect, or “ Gnat Midge,” of C. brassice is rather less 
than the twelfth of an inch (1-2 mm.) in length, with head and back 
of thorax dark or black, with silvery hair; the abdomen flesh-coloured, 
usually with brown or black bands. Antenne fifteen-jointed, those of 
the male shorter than the body, those of the female scarcely half its 
length. Legs black, silver white beneath, turning lighter after death. 
Wings transparent, flesh-colour at the base, very brightly iridescent ; 
the fore edge black, as also the veins; and the first long vein very near 
the edge.* The ovipositor yellowish white, with a capability of being 
greatly extended. 
The specimens sent me had been so long dead, and were so much 
injured, that I cannot take on myself to state their species with 
certainty; but the position of the foremost long vein near the fore 
edge of the wing was very observable, and so also was the remarkable 
iridescence of the wings. Both Professors Schiner and 'Taschenberg 
note that this kind turns black after death, which was certainly the 
case with my specimens, but may be the case with other kinds also. 
The following notes, by Dr. J. Ritzema Bos, give the life-history 
of the infestation at greater length than I have been able to find it 
elsewhere :— 
“The maggots, which are about two millimetres in length, are 
milk-white, with the yellow food-canal showing through the skin ; 
they are to be found in the last half of May and in June in Rape-pods, 
and may be found there in very great numbers, even up to forty or 
fifty in one pod, where they suck the unripe seeds to such an extent as 
to destroy them before the time of ripening. The pods swell at the 
maggot-infested spots, and ripen and wither also earlier than those 
which are uninfested, and burst open, and the larve fall to the ground, 
where they change to pupal state. In about ten days a swarm of little 
Gnat Midges make their appearance, and these again lay eggs in the 
pods, which are to be found at the upper part of the stalks of Rape 
or other cruciferous plants. In the province of Groningen, in the 
Netherlands, I have repeatedly seen the Gnat Midges to be very 
injurious to the Rape. Means of prevention scarcely appear to be 
applicable.’’ —(J. R. B.) 
* « Erste Liingsader dem Rande sehr genihert.” For full description of imago 
see ‘Fauna Austriaca: Die Fliegen (Diptera),’ of Schiner, vol. ii. p. 374; and also 
‘ Praktische Insektenkunde,’ of Taschenberg, pt. iv. p. 8. 
+ See ‘ Tierische Schiidlinge und Nitzlinge,’ von J. Ritzema Bos, p. 588. 
