794 
Journal of Agricultural Research 
Vol.V, No. 17 
far smaller number of adults, yet a sufficient number to infest bananas 
were they readily subject to infestation. In this district 57 traps caught 
no flies between August 9 and 21, 1913, while the average for the samp 
period for 119 traps in which flies were caught amounted to 7.5 adults. 
Flies were taken in all traps hung at Moanalua, Waikiki, and Moiliili, 
although some of the traps were hung in the center of the largest 
blocks of trees. At Moanalua as few as 22 and as many as 3,334 adult 
flies were taken from individual traps between July 15 and August 
29, i9 I 3> while at Waikiki and Moiliili as few as 1 and as many as 402 
adults were taken between June 17 and July 8, 1913. Thirty-six was 
the largest number of flies taken from any trap at Waialua between 
August 9 and 21, 1913. Although only males were caught in the traps, 
adults caught in the hand net showed the sexes to be present in the usual 
proportion among the banana plants. These data determine at once 
the fact that the general immunity of bananas is not due to any lack 
among banana plants of adult fruit flies capable of ovipositing. 
ABSENCE OF INFESTATION AMONG RIPE AND GREEN BANANAS, AS 
EVIDENCED BY FIELD INSPECTIONS AND LABORATORY REARINGS 
During the period of somewhat over three years that the Federal 
Government has had supervision of the inspection of export bananas in 
the Hawaiian Islands (from August, 1912, to the present time) the writ¬ 
ers have seen no case of infestation among ripe or green bananas grown 
under normal field conditions, and neither have the banana inspectors. 
Frequently individual fruits on a bunch of bananas will ripen in advance 
of the other fruits. When the bunches are cut, these prematurely ripe 
fruits, which often in addition have the peel split so as to expose the 
pulp, are removed before shipment and discarded at the packing sheds. 
If any bananas are subject to infestation, it would seem that these fruits 
are most likely to be; yet 1,044 prematurely ripened fruits brought to 
the laboratory during 1913 and 1914 and placed in rearing jars yielded 
no adult flies, although they came from fields known to harbor adult flies. 
During August, 1914, when large numbers of flies were maturing from 
peaches in a garden in Manoa Valley, fully ripe Chinese bananas, and a 
variety known to the Hawaiians as the apple-banana (Musa sp.), growing 
in the midst of other species of infested fruits, showed no infestation. 
Thirty-nine fully ripe apple-bananas grown near the insectary from which 
flies were continually emerging showed no infestation. An examination 
of 27,000 fruits of the Chinese banana ready for shipment at several banana 
fields at Moanalua during early July, 1913, when records showed the adult 
flies to be very abundant, failed to reveal a single distinct egg puncture. 
Even suspicious abrasions were investigated and found not to extend 
through the skin nor to contain fruit-fly eggs. An examination of 3,500 
similar fruits at Kalauao during July, 1913, also gave negative results. 
No fruit flies have been reared from about 1,000 green Chinese bananas 
