INSECUTOR INSClTL^ MENSTRUUS 133 



Macromastix dichroithorax, new species. 



Male. — Length about 9-9.2 mm. ; wing, 12-12.5 mm. 



Female. — Length, 8.5-9.5 mm. ; wing, 11.5-13 mm. 



Generally similar to M. zeylandiae, differing as follows : 



Size smaller. 



Head rich fulvous, light gray adjoining the inner margins of 

 the eyes. 



Mesonotum light gray laterally, with three conspicuous ful- 

 vous to reddish stripes, the lateral stripes often much darker 

 (brown) than the median stripe, this latter sometimes narrowly 

 divided by a pale line; scutum light gray, the centers of the 

 lobes dark brown, these markings being backward continua- 

 tions of the lateral praescutal stripes ; scutellum and post- 

 notum obscure yellow, the latter darker posteriorly. Pleura 

 clear gray. Legs with the coxae clear light gray. Wings with 

 Rs a little longer ; m-cu short or punctiform ; cell 2nd A very 

 narrow. 



Abdomen with the basal tergites yellowish laterally, brown 

 medially ; second tergite broadly brown medially ; remaining 

 tergites rich fulvous orange with a narrow, dark brown, median 

 stripe, the lateral margins of the segments broadly buffy gray ; 

 sternites dark brown, the caudal margins of the segments nar- 

 rowly grayish. Male hypopygium differing in several con- 

 spicuous details from that of M. zeylandiae ; ninth tergite wide, 

 the caudal margin with a broad V-shaped median notch ; inner 

 pleural appendage with the cephalic end produced into a slen- 

 der, cylindrical beak that is capped by a single powerful black 

 spine ; about twenty-five similar spines on the dorsal and caudal 

 margins of the lobe, mostly arranged in a single row. 



Habitat. — New Zealand. 



Holotype, $ , Otago (from Osten Sacken's collection). 



Allotopotype, 9 . 



Paratopotypes, 8 9 's. 



