104 



Insects most injurious to Cultivators : — 



pupae. Many of the perfect insects produced from these leaf- 

 miners are amongst the most brilliant of lejDidopterous insects ; 

 their wings, of tiny size, being ornamented with patches of gold 

 and silver. Besides which, they are liable to the attacks of 

 parasites equally beautiful with themselves ; so that the investi- 

 gation of leaves infested with miners will amply repay the time 

 bestowed on their examination. 



But the instances of leaf-mining which are the more imme- 

 diate objects of this article, are far more detrimental than those 

 of the rose-leaf-miner and some others, which only form a 

 slender line along the leaf; inasmuch as the entire leaf, or, at 

 least, great patches of its surface, are consumed and withered ; 

 and, as this takes place in the autumn, it is impossible that the 

 plants can throw out fresh leaves to make up for what they 

 have lost. 



During the autumn of 1837, my attention was directed by 

 Mr. Lumsden, one of the assistants in the Horticultural So- 

 ciety's garden at Chiswick, to the state of the celery, of which 

 the leaves had to a great extent the appearance of having been 

 scalded with hot water. About the same time my father (who 

 was trying some experiments in order to grow his celery of the 

 size which it had attained in the garden of a friend, who had 

 taken the prize for this plant for several years, at one of the 

 provincial horticultural shows*,) found his plants attacked in a 

 similar manner: and, during the past autumn, the celery in the 

 gardens to the south of London especially has suffered; Mr. 

 Loudon having sent me specimens received from Bromley, 

 where the insect was injuring all the celery crops in that part of 

 the country, and had done so for two or three years past. Of 

 course, the blighted appearance of the leaves is attributed, either 



to the strong wind, or the cold spring, or the hot sun having 

 scorched the plants, while in a wet state, from a shower in the 

 heat of the day. I have endeavoured, inj%. 21. a andB, to give 



* One stick of this gentleman's celery was sufficiently large, with cold 

 meat, to sup twelve of his friends. 



