DISEASES OF THE PEAR TREE ] 243 



gall-like folds of the margin of the leaf. A pear tree 

 may have many leaves affected by this disease, but the 

 injury is generally hardly noticeable. The other species 

 is the execrable fruit fly (Halterophora or Ceratitis 

 capitata) for which see under Citrus trees. Contrary to 

 what happens in Italy, this fly attacks here all pears 

 which are still on the tree after mid- August, so that in 

 badly infested localities, in the first or second week of 

 September, it is not possible to find a single pear which 

 has not been punctured by the fly, and the crop becomes 

 a total loss as the maggots which develop in a few days 

 soon make short work with the grower's hopes. As soon 

 as they are hatched the maggots penetrate deeply into 

 the substance of the pear, establishing themselves around 

 the core, and the fruit soon rots and drops off the tree, 

 or if in the meantime it has been harvested and taken 

 into the fruit room, rots there all the same. The winter 

 pears although still quite green and hard in September, 

 are not spared, but are punctured in the same manner, 

 and the maggots develop in the same way without 

 waiting for the fruit to mature or to approach maturity. 

 The only known remedy against the fruit fly is the use of 

 small bags made of paper or better of any cheap cloth. 

 The fruit is put into the bags as early as possible after 

 mid-August, so that by the end of that month no fruit is 

 allowed to remain without this protection, and the bags 

 are removed only at the time when the fruit is cut and 

 taken into the fruit room. The best bags are those 

 made of muslin or other light cloth with open mesh, but 

 the cloth should not touch the fruit ; as otherwise the 

 fly is sure to reach through the cloth by its powerful 

 ovipositor. The fruit-room should be kept dark not only on 

 account of the fruit, but also to keep away the fly which 

 otherwise may find its way into the room and proceed to 

 puncture the fruit as if it were still hanging on the tree. 



Among the Lepidoptera there are three species of 

 moths which sometimes cause considerable havoc in our 



