364 PROCEEDINGS OF THE NATIONAL MUSEUM vol.86 



fig. 14) between sacculus and costa ; uncus truncate and short in pro- 

 portion to its breadth ; vincuhim short, truncate, ahuost square in out- 

 line; anellus with base rather broadly sclerotized, arms short, broad, 

 slightly twisted; aedeagus very short, stout, partially sclerotized (on 

 ventral half only) . The entire genitalia have a squat appearance that 

 is characteristic. 



Female genitalia with signum developed as a ridged plate with in- 

 wardly projecting ridge bluntly serrate (except in glaucatella^ in 

 which the signum is as in Cahela poTiderosella) ; bursa copulatrix 

 large, finely scobinate, especially in neighborhood of signum ; ductus 

 bursae scobinate at genital opening and with a pair of more or less 

 defined sclerotized plates on the dorsal membrane of the ductus at 

 the opening ; ductus seminalis from bursa near signum (but somewhat 

 farther removed than in Cahela). 



Larva of only one species {glaucatella) known; whitish, not banded 

 or conspicuously spotted; solitary in habit; stem borer in Cylindro- 

 jmntia. 



Eggs laid singly. 



Remarks. — This genus is very close to Cahela, and for some time I 

 hesitated about erecting it, for both genera have similar larvae and 

 host associations and a like structure of the gnathos; but there are 

 too many other differences in male characters and adult habitus to 

 permit their lumping. The partially sclerotized aedeagus, the short 

 stout arms of the anellus, the squat appearance of the whole male 

 genitalia, the porrect male labial palpi, and the serrate male an- 

 tennae at once distinguish the males of Rumutha from those of Ca- 

 hela; and i\\Q^ wing patterns readily separate both sexes. In Rmimtha 

 the discal dot is prominent and the transverse lines on the fore wing 

 are well defined for at least half their length. In Cahela the distinc- 

 tive wing markings are longitudinal. 



Three species are recognized as belonging to the genus. Its dis- 

 tribution is limited apparently to the southwestern part of the 

 United States and possibly the adjacent regions of northern Mexico, 

 although as yet no specimens have been received from Mexico. 



KEY TO THE SPECIES OF RUMATHA 



1. Ground color of fore wing white ; expanse 20 mm or less. 



1. glaucatella (Hulst) 

 Ground color of fore wing fuscous ; expanse 23 mm and over 2 



2. Indentation of subterminal line of fore wing between veins 5 



and 6 deep, extending to cell ; no pinkish scaling on costal area 



of fore wing 2. bihinda (Dyar) 



Indentation of subterminal line of fore wing between veins 5 and 6 

 shallow, not extending to cell ; a scattering of pinkish scales 

 among white scales on costal area of fore wing 3. poling-ella (Dyar) 



