THE CANADIAN ENTOMOLOGIST 



53 



Leaf-Rollers and Green Fruit Worms. — These are greenish 

 caterpillars that attack the apples soon after they are formed 

 and frequently eat deep holes in them. As the apples grow these 

 injuries callous over but are often so deep that the fruit is dis- 

 torted and cannot be marketed. Any other biting insect that eats 

 out similar areas may also cause a deformed fruit. 



Other Causes of Deformities. 



Although most of the deformities of apples are caused by 

 insects, a number is due to some of the following factors: Frost 

 injury, fungus diseases, imperfect fertilization. Bitter Pit disease 

 or spray injury. 



Frost Injury.— Fruit recently set may become partly fro^en 

 with the result that the injured area will fail to develop normally 

 and a malformed apple will be produced. It is claimed that frost 

 injurv to blossom buds may also cause deformed fruits. 



Fungous Diseases. Any fungus disease, such as Apple Scab, 

 which attacks one side of the apple much worse than the other, 

 will by interfering with the growth of that side cause a deformity. 

 Bitter Pit Disease. — -This is a disease of apples due neither 

 to a fungus nor a bacterium, but so far as known to weather con- 

 ditions. Good growing weather in spring, or early summer 



followed by drought, 

 seems in Ontario to 

 be the chief cause. 

 Soil conditions and the 

 individuality of the 

 tree are apparently 

 contributing factors. 

 The disease takes 

 various forms ; some- 

 times the apples look 

 cjuite sound but, when 

 cut open, are found to 

 have dry dead areas 

 here and there through 

 them; at other times, 

 especially in the case 

 of Baldwins, the sur- 



-Duchess Apple deformed by a very severe attack f„„„ ,"o r^',i-ic.A -.^-If li 



of Bitter Pit Disease. I2ice IS piticn W lln 



Fig. 4. 



