DIPTERA. 359 



Chromatomyia ilicis, Curtis. 

 Phytomyza ilicis, Kalt. 



(Holly Leaf-miner.) 



In many parts of the country this pest, known by the name of the 

 Holly Leaf-miner, is very abundant. In fact, it is quite the exception 

 to find specimens of the common holly, Hodgkin, and a few other 

 varieties, to be quite free from it. (Fig. 338.) 



The flies are very easily hatched out by artificial means, if the 

 infested leaves on shoots from the previous year are gathered, after the 

 larva has changed to the pupal stage, by the latter end of April or 



Fig. 337. Leaf of snowberry mined by Fig. 338. Leaf of holly blotched 



Chromatomyia obscurella. by Chromatomyia ilicis. 



beginning of May. In Northumberland the flies hatch out in the 

 first week of June. 



In general appearance the fly resembles a small specimen of the 

 common house-fly. Expanse of wings, 3^ to 4 mm. Eyes of a shining 

 chocolate colour. Body, as a rule, entirely black and hairy. Wings 

 hyaline ; veins black ; halteres waxy white. Under side of abdomen 

 sometimes slightly yellow, and on upper side of abdomen there are 

 frequently narrow whitish bands across the segments. 



The full-grown larva is about 3 mm. long, white and footless, and 

 the puparium is rather shorter, barrel-shaped, and of a leathery colour 

 and texture. 



As regards the life-history of this species, I have several times tried 

 to work it out, and so far as my observations go, they coincide with 

 the following description from Mi Collinge, the University College, 

 Birmingham : 



