10 BULLETIN 134, U. S. DEPARTMENT OF AGRICULTURE. 



in these operations, although not with entire success, to prevent 

 infection from molds, which gave considerable trouble. In 12 experi- 

 ments 163 larvae were transferred into lemons, and 108, or 66.2 

 per cent, changed to pupae and emerged. The time spent in the 

 lemons varied from 2 to 10 days, with an average maximum of 7.7 

 days. 



The length of the larval period was determined as 10 to 11 days. 

 On this basis the age of the larvte transferred varied from 1 or 2 to 

 10 days. It will be noted that not all the larvae developed, 33.8 

 per cent having died from one cause or another. The molds in the 

 fruit were probably the chief factor in the mortality. The exuding 

 juice drowned a good many that were emerging for pupation, others 

 were dead in the fruit, and possibly some were injured in the transfer. 

 Enough, however, emerged to show that the lemon is not an impos- 

 sible food for the larvae of Ceratitis capitata. 



In each of 48 glass jars from 1 to 2 lemons were placed and 

 from 6 to 22 flies liberated. These were fed with sweetened water, 

 and lived from 3 to 26 days, the large majority, however, dying 

 after 6 or 7 days. No infested lemons resulted from these experi- 

 ments and no punctures were found. Under the same conditions 

 peaches, pears, and oranges became infested, but with these some 

 of the experiments also resulted negatively. Apples in three jars 

 were not infested. In only a few cases were flies seen in copulation, 

 and it appeared that they were too closely confined and under too 

 unnatural conditions for free breeding. 



In four large breeding boxes, where infested fruit was placed on 

 the ground and the flies allowed to emerge, a total of 56 lemons in 

 all stages of ripeness was placed. In 2 of these boxes the fruit 

 was first punctured with a needle or scalpel, and in the other 2 

 the lemons were sound. Some of the lemons remained in these 

 boxes for 6 weeks. Hundreds of flies emerged in each of the boxes. 

 The lemons, when examined, were in various stages, many being de- 

 cayed. No infested fruit was found, and no punctures of the fruit-fly 

 were seen in any of the lemons. 



While these experiments were not, of course, extensive and ade- 

 quate enough to establish any fact on negative evidence alone, they 

 do show that oviposition in the lemon in Italy is not at all common. 



PUPATION. 



Ordinarily fruit-fly larvae go into the soil to the depth of about 

 an inch, or otherwise seclude themselves for pupation; but this is 

 not at all necessary, and pupation may occur anywhere in the open 

 and direct light. The side of a packing box or any other container 

 of fruit is thus suitable for the purpose, and the fruit-fly may be 

 transported in this manner. 



