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



INFESTATION OF ORANGES. 



Oranges were not found infested with the fruit-fly during April and 

 May. By the end of May oranges are almost entirely off the market 

 in Sicily. Much orange fruit was examined during April and May, 

 both on the Island of Sicily and on the mainland, but no infestation 

 was found. In Calabria and at Messina oranges were seen with fruit- 

 fly punctures from the previous season, but no larvae were present. 

 The eggs failed to hatch or the larvae died immediately upon hatching 

 without getting beyond the egg cavity. According to Dr. Martelli, 

 entomologist at Messina, who has given considerable attention to 

 the fruit-fly, oranges may usually be found infested by the 1st of June, 

 but none was found with living larvae anywhere, to the writer's knowl- 

 edge, up to the second week in June of 1913. 



When the writer returned to Sicily on the 1st of August such ripe 

 oranges as were still on the trees or on the ground were heavily 

 infested with the fruit-fly (PL I, fig. 2). Indeed, no oranges could 

 be found that were either not infested or did not show punctures. 

 For some reason unaccounted for, a few oranges among an almost 

 complete infestation will show from two or three to a dozen punc- 

 tures, yet will remain sound and contain no larvae. One orange taken 

 late in August contained the remarkable number of 118 larvae (PL I, 

 fig. 5). These were mostly full grown, and the orange was below 

 medium size. The pulp alone did not furnish sufficient food for such 

 a number, so many of them had retreated to the denser rind, and it 

 was necessary to cut this into very small pieces to disclose the. larvae, 

 which were concealed in small burrows. This orange, before it was 

 cut, was firm and undecayed. 



The usual number found in oranges varied from 6 or 7 to 15 or 20. 

 In peaches there were about the same number, but occasionally as 

 many as 30 or 35. In figs usually from 3 or 4 to 8 or 10 were found, 

 while in azaroles and plums, which are smaller, from 2 or 3 to 5 or 6 

 would be the usual numbers. 



Both the sweet and bitter oranges were infested. The bitter 

 orange, therefore, at least as it occurs in Sicily, is not objectionable 

 as food to the fly. The pomelo, or grapefruit, is very rare in Sicily, as 

 elsewhere in Europe, so that a fair test of possible infestation was not 

 presented. A few old grapefruit, however, occurring on three or four 

 trees that adjoined orange trees on which all the fruit was infested, 

 showed no larvae or punctures. Mandarins are, of course, commonly 

 infested. (PL I, fig. 4.) Occasional ones, apparently remaining 

 over from the previous year, were collected as late as August, and 

 these were in nearly ail cases infested. 



The first oranges of the crop of 1913 with fruit-fly punctures were 

 seen about the middle of September. This fruit had begun to turn 

 yellow over a small area on one side, and the punctures were in this 



