1867.] 149 



and examined by a low power, is found to contain a newly hatched 

 larva ; some may be observed extended at full length in the egg-shell, 

 whilst others are in a coiled position. 



The young larva has a very hyaline look, the mouth with a pinkish 

 tinge, with a small white spot on each side of the back of the second 

 segment, the dorsal vessel is white, but only visible on the 7th — 10th 

 segments ; the head is somewhat wedge-shaped. As soon as the larva 

 is sufficiently developed, it quits the egg-shell and pierces the cuticle of 

 the leaf, and commences feeding on the parenchyma, where it is after- 

 wards joined by its fellow larvae, and they continue feeding side by side 

 in little communities, varying in numbers from two to twelve. The 

 part of the leaf where the larvae are feeding becomes slightly dis- 

 coloured, in consequence of the tissues having been devoured by the 

 larvae, and thus gives the first outward indication of their presence.* 



If we take up a larva at this early period of its life, we find that, 

 when dropped, it has not a silken cord ready to break its fall, but falls 

 helplessly to the ground. 



After the first moult the head of the larva becomes roundish, and 

 is slightly suffused with pale brownish, and it has three minute dark 

 brown marks on each side ; the mouth is brown, the body is white, but 

 without its previously glassy look, the dorsal vessel is darker, and is 

 traceable as far as the penultimate segment. 



When arrived at this stage of its development the larva is not 

 content, as previously, with eating the mere surface juices of the 

 parenchyma, but eats large trenches in the cellular tissues of the leaf^ 

 always, however, taking cai'e not to pierce the outer cuticle 



At the expiration of three or four days the 4th — 9th segments 

 become dull yellowish, the anterior and posterior segments still retaining 

 their previous appearance. After the interval of one day the mouth 

 of the larva becomes of a dull red, the whole of the body becomes 

 white, and the dorsal vessel turns pale green ; in doing so, however, it 

 imparts a greenish tinge to the body ; the larva now, for the first time, 

 possesses the power of spinning a silken cord. 



By this time the leaf on which the larva and its companions have 

 been feeding has become much blotched ; the larvae now enter upon a 

 new phase of their existence, for, quitting the mine in which they have 

 hitherto lived by biting holes in the upper surface of the leaf, they 



[* It is at this period of its existence we can most easily check the ravages of this insect ; we have 

 but to pick the leaves that are just blotched, and we destroy all tlie larvse within thera. Each individual 

 larva, if allowed to grow to its full size, would have destroyed or discoloured two or three lilac loaves.— 

 U.T. S.] 



