64 INSECT ARTIZANS AND THEIR WORK 



flies. One of these is the Celery Fly {Trypeta 

 ono-p or dines), which also attacks the leaves of the 

 parsnip. Probably it would not seriously affect 

 the plant were its mines restricted to the developed 

 leaves of mature plants, but it attacks the tender 

 leaves of the seedlings and makes them sickly or 

 kills them right out. 



Another fly with leaf-mining grubs is the Holly- 

 leaf Fly {Phytomyza ilicis). Holly-trees are often 

 seen to have scarcely a leaf that has not one yellow 

 blotch upon it, and often there are several blotches 

 on one leaf, testifying to the work of as many 

 miners. The mines are rarely serpentine, but 

 mostly shapeless patches, the grub turning about 

 and eating the parenchyma as far as he can reach 

 on all sides without moving his hind body. The 

 eggs are laid in summer, and the grubs go on 

 feeding right through the autumn and pass the 

 winter in the pupa condition, issuing as small black 

 flies at the beginning of summer. 



Even the larva of one of the Sawflies is found 

 among the Miners. This is the Raspberry-leaf 

 Miner {Fenusa pumila), a minute four-winged fly 

 with black body and black- and-yellow legs. The 

 grubs feed upon the parenchyma in approved miner 

 fashion, and are sometimes in sufficient numbers 

 to cause alarm to the small-fruit grower. His 

 remedy is to go over the bushes and press the 

 mined leaves between finger and thumb, and the 

 mining work is stopped. 



