1867.) 
9 
NATURAL HISTORY OF CHBOSIS EUPHORBIANA, TREITSCHKE. 
BY PROFESSOR ZELLER, OF MESERITZ. 
Diagnosis of the larva .—Length 7 lines ; dirty greyish-gi-een 
(darker when young), slightly glossy ; the head heart-shaped, black ; 
the thoracic plate, divided down the centre, is black, as, also, the 
rounded anal plate and the anterior legs ; the mouth is reddish-brown ; 
the jDalpi yellowish-green. 
The head is black, with pale hairs. Tho thoracic plate is broader 
than long, truncately cordate, divided in the middle by a slender, pale 
longitudinal line, clothed with pale hairs ; beneath it, before the very 
small dark spiracle, is a large dark wart, bearing a hair, and beneath it 
above the black first anterior legs, a smaller one. On the second and 
third segments, near the slender darker green dorsal line, is a small 
wart, beyond it a rather larger one, and beyond it two smaller ones, at 
some distance from one another. On the remaining segments the 
ordinary spots have nothing diiferent from their usual position, and are 
not much darker than the ground colour, and can only be well distin- 
guished through a lens ; each bears a transparent, pale hair. The 
spiracles are small, and not easily perceived ; there is a small wart 
above them, and another on the lateral prominence beneath them. 
The ventral pro-legs are cylindrical, neither long nor thick, on the outer 
side with a small brown spot, above which is an elongate wart, with two 
pale hairs. 
The anal plate is broader than long, rounded, clothed with hairs. 
This larva, which is double-brooded, the first brood in June (when 
I have never yet observed it) and July ; the second brood towards the 
end of August and throughout September ; lives solitarily on Eupliorhia 
jmlusfris (perhaps, only exceptionally, on Euphorbia lucida), amongst 
the leaves of the terminal shoots, which it draws together lengthwise 
like a pod, and it therein feeds on the innermost leaves, probably 
without having occasion to change its place of abode. Its abundant 
excrement is collected at the lower end of the domicile. 
In cold, wet weather many larvae get killed, Floods, also, which 
in summer cover these plants with water, usually leave very few larvaa 
living. In captivity, this larva often eats, without injury, the dried 
leaves, producing only a smaller imago. It is very subject to the 
attacks of the larvae of Pteromali ; these hang on to the larva and suck 
its juices, sometimes six or seven at a time ; they are thick, fusiform, 
more pointed at the upper end than at the lower, many-ringed, dark 
grey, transparent at the margins. It is also attacked, not uufrequently, 
bv a moderate sized, red-legged, black Ichneumon. 
