332 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



From this table it is readily seen that kerosene used in traps as a 

 control for the Mediterranean fruit-fly is entirely out of the question, 

 for the number of fruit-flies captured during the last four days is not 

 smaller than the number caught during the first four days. Further- 

 more, of the 10,239 flies captured, only 36 were females, the remainder 

 being males. And again, at the end of the fifth week almost every 

 ripe orange was ''stung" by the pest. 



, During the next five weeks the fruit-fly spray was applied to all of 

 the fruit-bearing trees, about once a week, under the most unfavorable 

 weather conditions. The applications of the spray were made during 

 the rainy season and since this orchard is situated on the outskirts of 

 Honolulu in Manoa Valley where rains are more frequent than in the 

 city itself, the effectiveness of the poisoned bait was to receive a most 

 thorough test. The rains were so frequent in this valley that the 

 spray rarely remained on the leaves of the trees more than a day or 

 two at the most and in one instance only a few hours before a rain fell. 

 Hundreds of fruit-flies were present in this orchard before the applica- 

 tion of the first spray and at this time it was an easy matter to capture 

 several hundred specimens in an hour by sweeping with an insect net 

 among the orange trees. This orchard was not isolated but was adja- 

 cent to a very much neglected orchard which was also teeming with 

 the pest. Horticultural sanitation was not rigidly practiced through- 

 out this entire experiment. All fallen, infested, citrus fruits, however, 

 were collected daily and thrown into a barrel containing water, but 

 since the larvae of the pest are able to live for several days in fruit 

 submerged in water, the fruit was removed from the barrel from time 

 to time and burned. The wind breaks of this orchard consisted of 

 high guava trees but very little of the fallen fruit from these trees was 

 destroyed although the same was infested. Papaias, plums and 

 tomatoes were allowed to decay on the ground. The following table 

 shows the number of fruit-flies which were captured in the traps during 

 and after spraying: 



TABLE II 



Number of Male and Female Mediterranean Fruit-Flies Captured in Ten 

 Kerosene Traps at Intervals of Two to Five Days for a Period of Five 



Weeks During and After Spraying 



& 9 



After first spraying, Nov. 12-14, three days' catch 51 2 



After first spraying, Nov. 15-17, three days' catch 40 0 



Six days' catch 91 2 



After second spraying, Nov. 18-21, four days' catch 12 1 



After second spraying, Nov. 22-23, two days' catch 0 1 



After second spraying, Nov. 24-26, three days' catch 8 0 



Nine days' catch 20 2 



