THE MELON FLY. 31 



cheap. They could be grown in every dooryard. Because of the 

 ravages of the pest, these crops can not be grown now by the average 

 person, and only with great difficulty in market gardens. Many 

 fruits must be imported, and the cost of all has been increased as a 

 result of melon-fly attack. Even cowpeas and string beans may be 

 infested. It is impossible to overstate the destructiveness of the 

 melon fly to cucurbitaceous crops under Hawaiian coastal conditions, 

 where none of these can be brought to maturity except with the 

 exercise of the greatest care on the part of market gardeners. 



Since there are as many as 8 to 11 generations of the melon fly a 

 year, and the female flies may live to be over a year old and lay eggs 

 throughout life, the- pest can multiply very rapidly. No agencies 

 have been found to.be working at present in Hawaii that bring about, 

 even periodically, a great natural reduction in the abundance of 

 melon flies. No native parasites are known to attack the melon fly, 

 but it is hoped that the parasite introduced from India during 1916 

 may prove effective. In colder climates cold weather will prove a 

 marked and valuable control factor. Predacious enemies and several 

 forms of mortality recorded are of no practical value under Hawaiian 

 conditions. 



No satisfactory artificial measures have been applied' successfully 

 in combating the melon fly under Hawaiian conditions. Poisoned- 

 bait sprays promise to yield effective results under other cultural con- 

 ditions. In Hawaii these sprays would be effective if they were used 

 consistently and universally, but they are not. At present cucurbits 

 can be grown only by the use' of coverings of various sorts for the 

 protection of the very young fruit. Killing the immature stages by 

 submergence in water, by burial in soil, or by boiling are not applied 

 as methods of control, although they are effective when intelligently 

 applied. Artificial methods of control are not likely to prove satis- 

 factory in Hawaii so long as the growing of the chief host plants 

 remains in the hands of uneducated oriental laborers who do not 

 practice clean cultural methods or cooperate in applying remedial 

 measures. 



