THE CACTUS-FEEDING PHYCITINAE — HEINRICH 395 



Female genitalia without signum; ductus bursae long, finely sco- 

 binate only at genital opening or (in strigalis only) sparsely so at 

 junction of bursa copulatrix and ductus bursae, with two small scle- 

 rotized dorsal plates and a single ventral plate at genital opening 

 (the ventral plate absent in strigalis) ; bursa copulatrix large, smooth 

 (except in strigalis, in which it has a few minute scobinations) ; 

 ductus seminalis from near end of bursa. 



Larvae bluish, not banded or conspicuously spotted ; with two setae 

 in gi'oup VII on abdominal segments 7 and 8; gregarious feeders in 

 Ferocactus, Echinocereus, Peniocereus, and, probably, Camegiea. 



Eggs laid singly. 



Remarks. — The genus as here defined is distinguished from all 

 other genera of the cactus-feeding group by its filiform maxillary 

 palpi. Zophodia, which it resembles in most structural characters, is 

 not a cactus-feeding genus, has the male antenna unserrate, the labial 

 palpus of the female porrect, and a small signum in the bursa 

 copulatrix. 



Five species are recognized as belonging to the genus. They are 

 fairly easy to distinguish but subject to so much individual variation 

 in wing markings that it is very difficult to key them satisfactorily. 



The known distribution is the southwestern part of the United 

 States and Mexico. 



KEY TO THE SPECIES OF CACTOBROSIS 



1. Fore wing without transverse marliings and witli veins strongly 



outlined in black, the strongest black line from base to termen 

 along upper vein of cell and vein 6; abdominal tufts of male 



weak 5. strigalis (Barnes and McDunnough) 



Fore wing normally with transverse markings and with some 

 black scaling on veins ; but if transverse markings are absent, 

 veins are not strongly lined nor is there a conspicuous black 

 line from base to termen ; abdominal tufts of male strong 2 



2. Fore wing with a strong, submedian, luteous shade ; thorax pale 



clay color 3. maculifera Dyar 



Fore wing sometimes with a faint ocherous-fuscous tint on sub- 

 median area, but never with a strongly contrasted luteous 

 shade ; thorax grayish fuscous 3 



3. Fore wing without discal spot or transverse dark markings ; a 



nearly uniform grayish fuscous with a faint brownish tint. 



4. insignatella Dyar 

 Fore wing normally with dark discal spot and transverse dark 

 shadings; when suffused, pale slate-gray without brownish 

 overtint 4 



4. Pectinations of male antenna (at middle) longer than width of 



segments 1. fernaldialis (Hulst) 



Pectinations of male antenna not longer than width of segments. 



2. longipennella (Hampson) 



109335—39 5 



