542 



Grease-banding of Fruit Trees. 



[OCT., 



GREASE-BANDING OF FRUIT TREES. 

 Fred V. Theobald, M.A., F.E.S., &c. 



The process of grease-banding to catch the wingless female^ 

 of the Winter Moth (Cheimatobia brumata) has been in 

 vogue many years. Some, perhaps the majority of growers, 

 have found it successful; others have not. 



In order to ascertain the cause of the reported failures, a 

 number of experiments and observations have been made 

 during the last six years, which have shown most clearly the 

 great benefit to be derived from this system if it is properly 

 carried out. This, as will be shown, applies to standard trees, 

 but not to all bush trees. The three objects investigated 

 have been : — (i) To find out what insects harmful to fruit 

 trees are actually caught in the grease-bands, and the period 

 of their appearance; (2) the best position to band the trees; 

 and (3) the most successful class of grease to use. 



With regard to the first point, practically no observations 

 had previously been made ; with regard to the second, there 

 was some diversity of opinion ; and with regard to the last, 

 complaints have been general that the greases dry up too 

 quickly, and that they have to be constantly renewed. This 

 cannot always be done in wet weather, and the result is that 

 a few wet days may allow the females to ascend over the 

 dried bands. 



Insects against which Grease-banding is Used. — The 

 damage done by caterpillars to fruit trees is often very I 

 serious. Complete defoliation of plantations is by no means ! 

 unusual, and this not only means a loss of crop, but a 

 serious check to the growth of the trees. 



There are a number of different species of caterpillars found 

 feeding on fruit, foliage, buds, blossom, and even the rind 

 of the shoots.* By far the worst are the Looper caterpillars 

 or Geometers, the female moths being wingless. With the ex- 

 ception of defoliation by Lackey Moth in parts of Kent, the 

 only other instances of similar damage which I have seen on j 

 a wide scale have been -raused by the Winter Moth group. 

 It is for these that grease-banding is used. 



* A full account of these will be found in " The Insect and Allied Pests 

 of Orchard, Bush and Hot-house Fruits, their Prevention and Treatment." j 

 F. V. Theobald. (1909.) 



