72 [ DISEASES OF CITRUS TREES 



Rain and wet weather is the worst foe of the 

 fruit-fly, a good shower being enough to destroy the 

 fly before it has time to take shelter under the leaves. 

 In wet weather the fly becomes torpid and is washed 

 down by the first droplet of rain that falls upon it. 

 Wind only disturbs it and po^pones its deadly punctures. 

 Cold weather kills it, but by that time it has already 

 provided for an ample posterity. In the stomach of 

 the redbreast, the redstart, thci stonechat and other 

 insectivorous birds, have been found the remains of 

 the fruit-fly; such as wings, thorax, feet etc. Birds, 

 lizards, frogs and ants pick up many grubs when the 

 fruit falls from the tree. The fly is not known to have any 

 parasite belonging to the Ichneumonidae or Encyrtidae, 

 and this fact accounts for its appalling numbers in years 

 of drought. 



The fruit-fly is a lazy insect and never takes a 

 long flight, but is very alert, and on the approach of 

 danger flits away to a neighbouring branch, to return 

 soon after ; but when engaged in laying eggs it is so 

 absorbed in its work that it is easily crushed by the finger. 

 /It was proposed to touch with the finger besmeared 

 with honey a few oranges or other fruit in each tree, 

 and then with a sharp blow with the finger to destroy 

 the fly while intent on sipping the honey. However 

 when about to brood the insect cares not for the honey, 

 and although numbers of insects have been caught with 

 this simple proceeding it is not applicable for extensive 

 orchards. Small boards 10 c.m. square, besmeared with 

 honey and turpentine and hung on the tree answer the 

 purpose better, and require no constant attendance ; 

 the flies flock to the honey and are caught by the other 

 sticky substance. It is also possible to poison the fly by 

 means of a mixture of honey or molasses and arsenite 

 of sodium (in the proportion of 50 parts of honey to 3 

 parts of a strong solution of arsenite of sodium) applied 

 on small boards as above. All dropped fruit containing 



