28 BULLETIN 643, U. S. DEPARTMENT OF AGRICULTURE. 
of well-tamped soil, but have been known to force their way through 
2 to 3 feet of dry loose sand beneath which their pupae had been 
buried. 
Because burial and burning may be left to subordinates who may 
not have the interests of the owner so much at heart, boiling or sub- 
mergence in water is more highly recommended. The larva? will 
not injure cattle if the fruits are used as feed, but many larvae may 
escape before they are eaten ; hence this method of destruction is not 
recommended unless the fruits have a real value as a food. 
PROTECTIVE COVERINGS. 
The protection of fruits and plants by covering with soil, paper, 
or cloth is a great labor-consuming operation, yet this is the only 
method that will protect under present Hawaiian conditions. Even 
Fig. 23. — Protecting cucurbits from attack by melon flies. Each fruit (in this case 
of Momordica sp.) is placed, immediately after it has been fertilized, within a long 
envelope made of newspaper. (Authors' illustration.) 
as practiced to-day, less than 25 per cent of all fruits covered, except 
certain Chinese marrows, are actually saved from attack. In a 
slightly cooler climate than that of coastal Hawaii a high percentage 
of the fruits could be saved. As it is, the great attraction of the un- 
fertilized ovaries of the bloom makes it difficult to put on covering* 
before the flowers are infested. During the warmer portions of the 
year the bloom of cucurbits, with the exception of the cucumber, should 
be protected at least three to four days before the flower unfolds. 
At present many fruits are covered, but rather indifferently and 
ineffectively. During April only 9 out of 43 fruits of the Chinese 
melon that had been covered were sound, while on the same date 119 
