798 
Journal of Agricultural Research 
Vol. V, No. 17 
marked for shipment. The 18 punctures found on this fruit were made 
between June 28 and 30, or 7 to 9 days after the fruit was marked for 
shipment. All of these punctures were empty, and only 2 were sufficiently 
deep to contain eggs. The dried exudations have been removed. 
Having failed to force Mediterranean fruit flies to oviposit successfully 
in the field in bananas sufficiently mature for the export trade, freshly 
laid eggs were removed from apples and placed in incisions made in the 
peel of bananas marked for shipment but still attached to the tree. Small 
cuts varying from one-fourth to one-half inch in length, extending with 
the grain of the peel but not quite reaching the pulp, were made. From 
these cuts the sap flowed so freely that it was difficult to insert eggs quickly 
enough to prevent them from being washed away. A total of 470 eggs 
inserted were sealed within the incisions with gummed labels and a thin 
layer of paraffin. Upon the examination of 270 eggs 2 days later, it was 
found that 60 eggs had hatched and that the newly hatched larvae were alive 
and active within the incisions. Later examinations showed that all larvae 
died without entering the pulp, even where the peel had split and exposed 
the latter. An examination of the 200 other eggs 9 days after they were 
placed within the incisions showed that 135 had hatched, but all the 
larvae had died without infesting the pulp. The 275 of the 470 eggs that 
failed to hatch turned black. Of 65 eggs of the same lot held as a check, 
57 hatched. 
EXPERIMENTS IN THE LABORATORY 
All experiments carried on in the laboratory necessarily were with 
fruits cut from the tree. The results were therefore obtained under con¬ 
ditions less normal than those obtained in the field. No experiments can 
be said to be carried on under field conditions unless the fruit is still 
growing, for as soon as it is cut its protecting sap begins to disappear. 
One bunch of 55 fruits which had been cut for shipment for 24 hours 
was confined for 48 hours with about 500 fruit flies. An examination of 
the individual fruits after the bunch was removed from the cage showed 
22 with a total of 28 punctures. These punctures were not opened, but 
the fruits were placed in jars. No adult fruit flies developed. 
One bunch of 93 fruits, which had been cut for shipment for about 
6 hours, was confined for 24 hours with about 300 fruit flies. On 
removal from the cage it was found that only 15 fruits were free from 
attempts at oviposition. In the remaining 78 fruits there were 342 
punctures. Eggs were laid in only 7 of these 342 punctures. All eggs, 
or newly-hatched larvae, died in 5 of the 7 punctures and only 3 adult 
flies succeeded in developing, in but one of the two fruits the pulp of 
which was found infested 5 days after the fruit was removed from the 
cage. The fruits on this bunch were almost too mature for shipment. 
Twenty fruits from a bunch cut four days previously for shipment 
were confined in a jar containing about 400 fruit flies. Five fruits were 
