CITRUS FRUIT INSECTS IN MEDITERRANEAN COUNTRIES. 7 



had lived, although the number was sufficient to indicate that the 

 pulp of the orange was Hot too green or too acid to serve as food. 

 These oranges were perfectly green, there being no yellow whatever 

 on one and only a slight tinge over a small area on the other. The 

 inability of the larvae to reach the pulp seems, therefore, to be due 

 to an injurious substance in the rind, to lack of air, to decay, or to 

 all three combined. 



From examination of oranges in Italy, Sicily, and Palestine, as 

 they are maturing in the fall, there appears to be no possibility of 

 infestation until the fruit reaches maturity, even though eggs of the 

 fruit-fly may be deposited. The practical bearing of tois fact is im- 

 portant in greatly limiting the season of infestation. And in the 

 Mediterranean countries visited, cold weather appears by the time 

 the fruit is mature and susceptible to infestation, so that the season 

 is very short in the autumn, and most of the fruit is harvested 

 before the return of warm weather in the spring. 



APPEARANCE OF FRUIT-FLY PUNCTURES IN ORANGES. 



Immediately after the adult fruit-fly has oviposited in the orange 

 the puncture is not readily distinguishable, but it soon appears as a 

 brown or grayish, oval-shaped area about 0.5 mm. long, with a crack 

 or opening in the center. In green oranges the area immediately 

 around this may be yellow. Later this area may become brown and 

 depressed. After some time also the point of puncture is indicated 

 by a distinct conical elevation. These elevations are conspicuous on 

 the surface of the fruit and they may at once be diagnosed as indi- 

 cating punctures of the Mediterranean fruit-fly. In older fruit these 

 conical elevations may arise from circular depressions which are of a 

 brownish or yellowish color. If the outer layer containing the oil 

 cells be cut away, the egg cavity will be disclosed in the spongy tis- 

 sue. After some time brown and hard granular tissue usually sur- 

 rounds the egg cavity, so that the whole may be removed from the 

 surrounding tissue as a gall. To make sure that punctures are pres- 

 ent the egg cavity should be examined for the egg skins, shriveled 

 eggs, or larvae. If the orange is infested, small burrows may be 

 traced through the spongy layer to the pulp, and the pulp itself will 

 be decayed. Typical punctures are at once distinguished, but their 

 character and form vary so greatly that sometimes other scars or 

 abrasions on the fruit may be mistaken for them. 1 



INFESTATION OF LEMONS. 



The only supposed instance recorded of the occurrence of Cera- 

 titis capitata in lemons in Sicily is a note by Prof. Inzenga in the 

 Annali di Agricoltura Siciliana, Volume XIV, 1884, page 101. In 



1 Since the foregoing was written the writer has examined fruit-fly conditions in the Hawaiian Islands, 

 where they are strikingly different from those in Mediterranean countries. The most evident difference 

 in appearance of the fruit in Hawaii is the much more copious exudation of gum. 



