54 



BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



The dotted lines of figure 12 , indicate the general shape of the terminal chambers of the 

 tracheal system. The body is composed of 12 distinct segments, the last of which bears 

 the posterior stigmata upon the upper distal portion and the anus before the center 

 of the venter in the middle of a rounded tubercle (fig. 7, a). The head when viewed 

 ,-— N from above or below is bilobed ; each lobe bear- 



ing a distinct antennal protuberance; the dorsal 

 and more distal one terminating in a short incon- 

 spicuous arista; the more ventral one less anten- 

 nalike and without a terminal arista (fig. 7, b, c, 

 d). Mouth hooks sheathed (fig. 7, d). Body 

 armed only with inconspicuous spicules ar- 

 ranged in broken bands forming fusiform areas 

 on the venter of the 4-12 segments; portions of 

 the head and an irregular rind upon the anterior 

 portion of segments 2 and 3 armed with similar 

 spicules. There are no distinct fusiform lateral 

 areas of spicules. 



DURATION OP LARVA STAGE. 



Fig. 9.— Posterior spiracles of larvae of the 

 Mediterranean fruit fly: a, First-instar lar- 

 va?; b, second-instar larvae. (Original.) 



The duration of the larval instars has 

 been variously given by many writers. 

 Martelli found that larval development at Portici, Italy, required 

 from 9 to 10 days during summer, 11 to 12 days during early autumn, 

 and 15 days during November and December. Severin found that 

 larvae matured in the winged kamani ( Termindlia catappa) in from 8 

 to 17 days. Newman states that from 14 to 16 days during summer 

 and 25 to 45 (lays during winter in Western Australia are the periods 

 required for development. Other data might be given but they add 



Fig. 10.— Mandibles of larva of the Mediterranean fruit fly: a, First-instar larva; b, second-instar larva; c, 



third-instar larva. (Original.) 



nothing new to the foregoing information. No records previously pub- 

 lished except by the writers have been accompanied by temperature 

 data, hence they can not be satisfactorily interpreted. 



In Honolulu larval life 1 is completed within 5.1 to 26 days. The 

 data in Table XIV indicate the variation found in the developmental 



1 Back, E. A., and Pemberton, C. E. Life history of the Mediterranean fruit fly from the standpoint of 

 parasite introduction. Jour. Agr. Research, v. 3, no. 5, 1915, p. 363-374. 



