THE TURNIP FLY. 



95 



white butterfly and the " Phalsena," both insects belonging to 

 the order Lepidoptera, having four wings covered with five 

 imbricate scales resembling powder or meal. The butterfly, 

 or Papilio," has the antennae or horns thicker towards the 

 tip, and the " Phalaena" has them thicker towards the base. 

 Caterpillars appear in March, and are most frequent on cab- 

 bages and gooseberry bushes, though they are found at times 

 on the leaves of all fruit trees. They are most voracious, and 

 very quickly destroy every vestige of the leaves, and conse- 

 quently prevent the development of fruit, and the growth of 

 the vegetable. Various methods are used for removing them : 

 smoking the animals to death by an upward flame of glowing 

 brimstone, mixtures of black soap, flour of sulphur, mush- 

 rooms, and rain water, have been sprinkled over the trees and 

 bushes ; and " nux vomica " has been added with good effect. 

 These and similar apphcations have all had a temporary effect, 

 but the animals mostly always return in greater numbers. In 

 gardens, where the extent of space is limited, and under the 

 control of manual application, the most effectual method 

 of destruction will be to shake the animals from the leaves, 

 and catch them in a basket, and remove them wholly beyond 

 the garden. Those that fall to the ground can be gathered 

 up by spade or besom. TJie cabbages may be freed of them 

 in the same manner. In the field, where hand labour would 

 be very slow on account of the extent of the ground, and 

 where the space of the depredations is so much more exten- 

 sive, rolling of the plants is the only effectual mode of check- 

 ing the destruction. The roll may be light, and the opera- 

 tion may be more than once performed, as the animals, after 

 being in any way removed from the leaves, will creep from the 

 ground, and commence their work afresh. Apphcations of 

 soot and hot lime have been used ; but these substances only 

 reach the upper part of the leaves, and the animals live on 

 the under surface. Besides, it is not certain that these sub- 

 stances are destructive of animal life. 



2. The Turnip Fly is the Altica nemorum " of entomo- 

 logy, being a genus of " Chrysomela" of the Coleopterous 



