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



Italy. Most of the olives attacked fall to the ground before reaching 

 maturity. In the case of the olive fly, mature fruit is not at all 

 necessary for infestation. Because of the economical use made of 

 all the inferior fruit in these countries — something we have yet to 

 practice — infested olives are not a complete loss, for they are used 

 for oil, most of which is used in the manufacture of soap. The 

 striking difference in habits between the olive fly and the Medi- 

 terranean fruit-fly is that, with the former, pupation occurs within 

 the fruit, instead of in the ground or otherwise out of the fruit as is 

 the case with Ceratitis. 



Infested olives may be distinguished by a circular area on the 

 surface that is of a light gray color. Before entering the pupal stage 

 the larva eats out a channel to the surface of the fruit, leaving only 

 the thin epidermis. It is this, with the tissue eaten away below, 

 that forms the characteristic gray area that indicates infestation. 

 It is much the same as that made in the case of the pea and bean 

 weevils. Having completed the burrow to the surface, the larva 

 retreats a short distance and transforms to the pupa, enclosed in the 

 characteristic puparium, that looks much like that of Ceratitis. 

 Upon emerging the adult fly breaks through the epidermis, which 

 has been left for protection, by means of its ptilmum. 



Fortunately olives are not transported unless pickled, and thus 

 the danger of introduction is not great. But a sharp lookout should 

 be kept for any olives that might possibly be imported fresh from 

 these countries, since the egg, larval, and pupal stages are all passed 

 within the fruit. 



THE MEDITERRANEAN CITRUS FRUIT INDUSTRY. 1 



SPAIN. 



LOCATION. 



The most important citrus section of Spain, where 90 per cent of 

 the crop is produced, consists of a narrow strip, 10 or 15 miles wide 

 and 150 miles long, extending from Denia in the Province of Alicante 

 northward as far as Vinaroz in the Province of Castellon. This is 

 the so-called "Valencia section," the city of Valencia being situated 

 somewhere near the center of the strip. In this section are recog- 

 nized two distinct districts, the "Ribera" and the "Plana." The 

 "Ribera" lies to the south of Valencia and centers chiefly about the 

 towns of Alcira and Carcagente. This district is more or less rolling 

 and hilly and is separated from the sea, which is 15 or 20 miles 

 distant, by hills and mountains. The "Plana" lies north of the 

 City of Valencia and centers about the town of Burriana. This is a 

 perfectly flat plain and borders directly on the sea. Around the 



1 In this account of the Mediterranean citrus industry only such phases are presented as are necessary 

 to a better knowledge of the insects discussed in the earlier pages of this paper. 



