THE MEDITERRANEAN FRUIT FLY. 9 



no food; but if they can secure the juices of fruits or the honeydew 

 of insects, which form the "bulk of their food, they may live long 

 periods. Two flies lived for 230 and 315 days, respectively. But as a 

 rule lif e is much shorter, although many live to be four to six months 

 old. Many die when they are very young, even if they have had food. 

 In Honolulu females begin to lay eggs when 4 to 10 days old, 

 and, like hens, only much more faithfully, continue to develop and 

 lay eggs in fruits almost daily so long as they live. A female may 

 lay on an average from 4 to 6 eggs a day, 22 eggs being the largest 

 number known to have been laid by a fly during any one day. On 10 

 consecutive clays one fly laid 8, 11, 9, 6, 8, 3, 3, 3, 3, and 9 eggs; 

 another laid 0," 5, 14, 8, 13, 10, 6, 4, 4, and eggs. The largest 

 number of eggs laid during life by a single female kept in the labo- 



Fig 9.— Mediterranean fruit fly: a, Larvae, or maggots; 6, pupae, or chrysalids. Twice natural size. 



(Original.) 



ratory was 622. This fly lived only 153 days. It is probable that 

 800 eggs, or even more, may be laid by single hardy females under 

 favorable conditions. 



It is also important, from the standpoint of control, to know that 

 females deprived of a chance to lay eggs in fruits for a period of four 

 to six months when certain crops are not in season have the power 

 to begin depositing eggs as actively as younger flies when fruits 

 sufficiently ripe become available for oviposition. Thus one female 

 kept in the laboratory for the first five months of her life without 

 fruits in which to lay eggs laid 11, 4, 9, and 9 eggs during the first 

 four days of the sixth month of her life when fruits were placed in 

 the cage with her. 



CLIMATIC CONDITIONS FAVORING RAPID INCREASE IN HAWAII. 



The time required by the fly to pass through the egg, larva, and 

 pupa stages depends very much upon the climate. The chmate of 

 Honolulu and of the coastwise regions of Hawaii in general is very 



