October, '13] SEVERIN: MEDITERRANEAN FRUIT FLY 399 



THE LIFE HISTORY OF THE MEDITERRANEAN 



FRUIT FLY (CERATITIS CAPITATA WIED.) 



WITH A LIST OF FRUITS ATTACKED 



IN THE HAWAIIAN ISLANDS 



By Henry H. P. Severin, Ph. D. 



The life history of the Mediterranean fruit fly under HaAvaiian 

 conditions was worked out in the tropical almonds (Terminalia cat- 

 tapa). The tropical almond is a very common deciduous shade tree of 

 the Hawaiian Islands and bears clusters of compressed nut-like fruits, 

 each fruit being one to two inches long and resembling an almond 

 (Plate 9, figure 1). The fibrous shell of the nut is covered with a thin 

 pulp (Plate 9, figure 6) and it is this pulp that is seriously infested by 

 the pest. The pulp of the fruit is sweet and resembles somewhat the 

 taste of an apple. 



Deposition of Eggs. — In ovipositing the Mediterranean fruit 

 fly "stings" the fruit with its needle-like ovipositor, forming a small 

 receptacle within which the eggs are deposited. A secretion is then 

 poured over the eggs by the fly and this acts on the surrounding tissue, 

 changing it into a brown gelatinous substance. This gelatinous sub- 

 stance often exudes out of the mouth of the receptacle and hardens. 

 Green peaches that have been punctured by the pest show the gummy 

 exudation (Plate 9, figure 3) more conspicuously than tropical alm- 

 onds similarly affected. Green and ripe lemons may also show evi- 

 dence of a resinous material which exuded from the wound produced by 

 the ovipositor. Green oranges when "stung" often show a premature 

 ripening around the puncture. In some unripe fruits the secretion 

 poured into the receptacle formed by the female fly prevents further 

 growth of the tissue in this region, and results in the formation of a 

 depression on the surface of the fruit. (Plates 9, 10, figures 1, 2 and 10). 



The number of eggs which the fruit fly deposits within the recep- 

 tacle varies from 1 to 42. Five receptacles within a tropical almond 

 contained 15, 18, 30, 33 and 42 eggs, or a total of 138 eggs. The pulp 

 of the tropical almond and other fruits is often punctured by the ovi- 

 positor and yet no eggs are deposited. 



The fruit fl.y is unable at times to withdraw its ovipositor from some 

 fruits. An unripe tropical almond was found in which the distal end 

 of an extended ovipositor was caught within the fibrous shell of the 

 nut, while the rest of the body was missing. In all probability the 

 missing part of the body of this specimen had been devoured by a 

 lizard. The female fly is often unable to withdraw its ovipositor from 

 the sticky, milky juice of the unripe star apple and dies as a result of 

 starvation (Plate 10, figure 14). 



