STATES OF INSECTS. 189 



between the colours of the caterpillar and those of the 

 future moth ; the one is that of the common currant- 

 moth (Phalcena G. grossulariata L.), the caterpillar of 

 which is white, ornamented with several black spots va- 

 rying in size. At the two extremities it is yellowish, with 

 a longitudinal 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 or- 

 namented 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 a . The other is that of a green caterpillar, which 

 gives a green moth, figured by Reaumur (Pyralis prasi- 

 naria Fab.) b Sometimes, also, the sex of the future per- 

 fect insect may be predicted from the colour it exhibits in 

 its first state : thus, the brown caterpillars of Noctua Pro- 

 nuba produce males, and the green ones females c . The 

 sexes, also, of N. exoleta and Persicarice differ in that 

 state. 



vi» To the full account of the Food of insects given in 

 a former letter d , which had reference chiefly to their 

 larva state, it is only necessary in this place to add a few 

 particulars not there noticed. Many larvae when first 

 excluded, as those of Pieris Cratcegi, &c. devour the 

 shells of the eggs from which they have proceeded e ; and 



a De Geer i. 57. b Ibid. 58. Reaum. i. t. xxxix./. 13, 14. 



c De Geer ii. 400. d See above, Vol. I. Letters xii. xiii. 



e Bonnet (ii. 18) mentions, that the young larvae of a butterfly 

 (Pieris Cratcegi), after devouring the exuviae of the eggs from which 

 they were hatched, gnawed those which were not so : not, however, 



