188 STATES OF INSECTS. (Larva.) 
moth (Abrazas grossulariata), the caterpillar of which is 
white, ornamented with several black spots varying in 
size. “At the two extremities it is yellowish, with a lon- 
gitudinal ray of the same colour on each side, the head 
and legs being black. ‘These colours are all to be found 
in the fly, the ground of its wings being white ornamented 
with many black spots of different sizes. Its upper 
wings are traversed by a yellowish band; and towards 
their base is a spot of the same colour. Its body is 
yellowish, with black spots; but the head and legs are 
black*. The other is that of a green caterpillar, which 
gives a green moth, figured by Reaumur ( Tortriz prasz- 
nana)”. Sometimes, also, the sex of the future perfect 
insect may be predicted from the colour it exhibits in 
its first state: thus, the brown caterpillars of Catocala 
Pronuba produce males, and the green ones females °. 
The sexes, also, of Xylina exoleta and Mamestra Per- 
sicarieé differ in that state. 
_vi. To the full account of the Food of insects given 
in a former letter¢, which had reference chiefly to their 
larva state, it is only necessary in this place to add a few 
particulars not there noticed. Many larvee when first 
excluded, as those of Pieris Crategi, &c. devour the 
shells of the eggs from which they have proceeded®; 
@ De Geer i. 57. > Ibid. 58. Reaum. i. ¢. xxxix.f. 13, 14. 
“ De Geer ii. 400. 4 See above, Vor. I. Letters xii. xiii. 
© Bonnet (ii. 18) mentions, that the young larve of a butterfly 
(Pieris Crategi), after devouring the exuviz of the eggs from which 
they were hatched, gnawed those which were not so: not, however, 
so as to destroy the included animal, but rather to facilitate its egress. 
Those also of Coccinella bipunctata which I lately bred from the egg, 
as soon as hatched began to devour the unhatched ones around 
