THE MELON FLY IN HAWAII. 13 



attack when very young, although one rarely sees fruit offered for 

 'sale in Honolulu that does not show some evidence of attack even 

 when very carefully selected. Cantaloupes and cucumbers may be 

 successfully oviposited in by the female fly up to the time they are 

 ready for market. While cantaloupe growing has been practically 

 abandoned in Hawaii since the advent of the melon fly, cucumbers 

 are grown without protection of any sort. Although practically all 

 fruits reaching a size fit for salad use show evidences of attack at 

 one or more spots, the percentage of fruits rendered unmarketable 

 is not large enough to force the oriental growers to cover the young 

 fruits, although it would appear disastrously large to American 

 market gardeners, who place a high value on their time. During 

 midwinter 150 out of 153 cucumbers ready for the market at Moiliili 

 were found variously infested. 



All cucurbits grow with such rapidity in Hawaii that the oriental 

 is willing to permit the pest to destroy fully 50 per cent of the fruits 

 rather than go to the expense of covering each fruit as soon as or 

 before it sets. All other cucurbits except cucumbers must be cov- 

 ered before or just after blooming to prevent wholesale injury. 

 Aside from the fact that the seedlings and vines of all cucurbits 

 except cantaloupe and watermelon are but slightly attacked, there 

 is little difference in the susceptibility to attack of the young fruits 

 under Hawaiian conditions. Inasmuch as the fly has been permitted 

 to increase unchecked since its introduction, it has become so abund- 

 ant that slight differences in inherent resistance to attack are not 

 evident among host fruits groAving in the field. The infestation is 

 excessive in all unprotected fruits. If by chance pumpkins, squashes, 

 and watermelons escape infestation until they are from 4 to 6 inches 

 in diameter they may reach maturity, although before they reach 

 maturity pumpkins and squashes may support numerous colonies of 

 larvae in open-surface wounds (PI. XX, fig. 1), and become badly 

 deformed. Out of 254 nearly full-grown pumpkins growing at 

 Kahuku, 250 were found variously deformed by H. F. Willard on 

 March 21, 1915. As many as 650 adults have been reared from a 

 pumpkin no more than 4 inches long; the staminate bloom while 

 still a bud may support as many as 37 well-grown larvae. 



TOMATOES. 



Tomatoes are very susceptible to attack. All tomatoes offered for 

 sale in Honolulu are apt to be infested, as shown by the reports of the 

 market fruit-fly inspector covering several months. Fifteen ripe and 

 partly ripe fruits examined by H. F. Willard at Hauula on March 21, 

 1915, were found to contain eggs or larvae. Such severe infestation 



