26 BULLETIN 643, U. S. DEPARTMENT OF AGRICULTURE. 
PARASITES. 
Hawaii has no native parasites that attack the melon fly, but the 
Hawaiian Board of Agriculture and Forestry has introduced a para- 
site from India. This parasite 2 was introduced at Honolulu during 
the early part of 1916, and has been re-ared and distributed in large 
numbers, but it is not known yet whether it will check the ravages of 
the melon fly in a practical manner. It has become established, how- 
ever, and promises to be useful. 
ARTIFICIAL CONTROL. 
Individual growers of vegetables in Hawaii are likely to be dis- 
couraged in the application of remedial measures for the control of 
the melon fly. Host fruits are grown in rotation in the numerous 
garden spots and market-garden areas chiefly by uneducated orien- 
tals, who do not appreciate the necessity for a united fight against 
the fly. The usual custom among these laborers is to permit infested 
fruits to decay in the field. In certain uncultivated areas the wild 
Sycos and Chinese cucumbers run wild and furnish fruits in which 
the melon fly can breed throughout the year, even though no culti- 
vated crops are grown. This abundance of cultivated and wild host 
fruits, coupled with a climate favorable for rapid multiplication, 
produces many adult flies which spread in all directions to render 
valueless all remedial measures except those that involve protective 
coverings for the fruits. 
It thus happens that no artificial control measures have been 
applied successfully in controlling the melon fly under Hawaiian 
conditions. The only means now employed to safeguard fruits is 
that of protecting the young fruits with some type of covering until 
they are large enough to withstand attack. Trapping adults has 
proved a failure, and killing them by spraying thus far has given 
poor results. If all growers would cooperate systematically (1) in 
the destruction of the eggs and larvae by submerging infested fruits 
in water or by boiling and (2) in the destruction of the adults by 
spraying, the value of spraying with a poisoned bait and of covering 
the young fruits would be enhanced to a point where either might 
be sufficiently effective to be recommended as satisfactory. But so 
long as the cultivation of host plants is largely in the hands of 
orientals and others who do not appear to be amenable to instruc- 
tion as modified by western standards, no relief can be expected. 
SPRAYING. 
Since adult melon flies do not deposit eggs for 2 to 4 weeks after 
emergence during the summer, and only after relatively longer periods 
1 Opius fletcheri Silv. 
