262 



INSECTS ABROAD. 



ami dome-like in the middle, and very flat round the ed^es, 

 so that the general shape is very much like that of the Helaeus, 

 which is figured on page 187. Their colour is deep green, 

 and they are profusely punctated. 



On each elytron there are three rather large spots, exceedingly 

 variable in shape and size. They always, however, occupy the 

 same positions : one, which is more or less oval in shape, at the 

 base, a rounded spot on the middle of the flattened edge, and 

 another near the tip. These spots, contrary to the usual struc- 

 ture of Beetles, are quite as brilliant on the under as on the 

 upper surface of the elytra; and if the elytra be opened and the 

 insect held up to the light, the spots shine out like the red 



danger-lamp of a railway. The body 

 of the insect is dark blackish green. 

 In the British Museum there is 

 a well-preserved specimen of the 

 larva of this species, which admi- 

 rably shows the very remarkable 

 characteristics of the Cassida larva- 

 It is rather pear-shaped, with a 

 boldly elevated back, and having 

 the whole of the body surrounded 

 by long radiating filaments, just like 

 the blazing rays with which the 

 ancients decorated the head of Apollo when represented in his 

 character of the Sun-god or Helios. The end of the body is 

 turned upwards, an attitude which is natural to it, and for a very 

 singular cause. 



It is now well known that leaf-feeding larvae live in reality 

 upon the juices of the leaf, and that the only object in biting 

 off and swallowing small pieces of the leaf is, that the digestive 

 organs may extract the juices which the mandibles or jaws could 

 not procure in sufficient quantity for the subsistence of the 

 larvae. As for the pieces of leaf themselves, they pass through 

 the digestive system almost unchanged, and, when ejected, can 

 be easily unrolled by steeping them in warm water, just like tea- 

 leaves. If they be then placed beneath a microscope, it is seen 

 that they have scarcely undergone any perceptible change, and 

 that even the delicate hairs which stud the surface remain in 

 their places. With most leaf-eating larvae, the ejected portions 



Fio. 1'28. — Mesomphalia illustris. 

 (Green, with red spots.) 



