MEDITERRANEAN FRUIT FLY IN HAWAII. 



91 



rather densly and closely hairy; transverse prescutellar sulcus provided with four 

 deep pits, of which the lateral ones are deeper than the median; the scutellum is 

 smooth and rather hairy; slightly crenulate laterally before the prealar pit; metano- 

 tum with a small median pit divided by a short carina, crenulate on the sides; pro- 

 podeum strongly and irregularly foveolate. Front and hind wings with the venation 

 shown in figure [PI. XXI, fig. 1]. Abdomen with the first segment smooth; ovipositor 

 straight, longer than the abdomen. Length of body, 3.6 mm. ; width of thorax, 0.1 

 mm. ; length of antennae, 5.2 mm. ; length of front wing, 3.7 mm. ; width of same, 1.37 

 mm.; length of third pair of legs, 4 mm. ; length of ovipositor, 3.5 mm. 

 $ . Differs from the female in having the wings more or less infuscate. 



Larva. — The newly hatched larva is similar to that of Opius humilis, 

 as illustrated by figure 20, a, b, as well as that of Diachasma tryoni, 

 but it may be readily distinguished from that of D. tryoni by the pos- 

 session of three instead of two toothlike projections 

 on the anterior margin of the ventral chitinized 

 plate of the head (fig. 23). 



Pupa.— The pupa, which is about 3.2 mm. long, 

 is most easily recognized from that of humilis and 

 tryoni by the length of the ovipositor. (Fig. 24.) 



BIOLOGY OF THE OPIINE PARASITES. 



Very little is known regarding the details of the 

 life history of the three opiine parasites introduced 

 into Hawaii. The biology of parasites now attack- 

 ing Ceratitis capitata in Hawaii is at present being 

 made the subject of special investigation by the 

 junior writer. No data on the length of the vari- 

 ous stages have been published except by Silvestri 

 and Gurney. Silvestri's statements may be sum- 

 marized as follows: That adults of Opius humilis 

 emerging on April 3, 1913, were still alive on his 

 arrival at Honolulu on May 16, when they depos- 

 ited eggs from which adults developed within 14 days; that eggs of 

 Diachasma fullawayi, at Dakar, Senegal, deposited on September 6 to 

 8, 1912, developed adults September 21 to 24, and that D. tryoni can 

 complete its egg, larval, and pupal development in from 14 to 16 

 days. The data supplied by Gurney deal with D. tryoni only and 

 will be considered later. The information of the writers is not com- 

 plete and therefore is given as follows in the form of biological notes 

 in anticipation of a more complete publication. It might be added 

 that such data as are presented here were obtained incidental to other 

 work. 



Length of adult life. — Adults die in about 48 hours if not fed. 

 When confined in test tubes \\ inches in diameter and about 8 inches 

 long and fed daily, they live much longer, as indicated by the data in 

 Table XXIV. 



Fig. 24.— Diachasma, ful- 

 lawayi: Lateral view 

 of pupa; normal length, 

 about 4 mm. (Origi- 

 nal.) 



