BIOLOGY OF THE COHOSTS. 



75 



lacunosa. In the Melia berries it is parasitized by Cerambycobius 



CUSHMANI, EURYTOMA TYLODERMATIS, and PeDICULOIDES Sp. 



CURCULIONID^. APIONIN^. 



Apion segnipes Say in Cracca virginiana is parasitized by Eury- 



TOMA TYLODERMATIS. 



Apion decoloratum Smith. Dr. Chittenden records this weevil as 

 breeding in Meihomia paniculata and parasitized by Catolaccus 



INCERTUS. 



Apion griseum Smith. Dr. Chittenden records this weevil as 

 breeding in Phaseolus retusus, P. wrigJitii, P. polystacJiyus, and 

 StropJiostyles pauciflora, and parasitized by Catolaccus incertus. 



Apion nigrum Smith. Breeds in buds of Rohinia pseudacacia and 

 is parasitized by Catolaccus incertus. 



Apion rostrum Say in pods of Baptisia is parasitized by Ceramby- 

 cobius CYANICEPS. 



CLEONIN^. 



Lixus musculus Say. This weevil is known both from the Lower 

 Sonoran and Austro riparian zones. It breeds in the stems of Poly- 

 gonum pennsylvanicum, P. portoricense, and P. 

 punctatum, making an oblong gall or swelling. 

 It is parasitized by Eurytoma tylodermatis, 

 Cerambyxobius CYANICEPS, Ncocatolaccus 

 tylodermse, GlyptomorpJia rugator, G. novitus, 

 and Eorismenus lixivorus. 



Lixus scrohicollis Boheman. This weevil (fig. 

 20) is probably confined mainly to the moist 

 Austral zones. It breeds abundantly in the 

 stems of Amhrosia trifida, A. artemisisefolia, 

 A. psilostachya, and Helianthus spp. It is 

 quite highly parasitized hjPtinohiusmagnificus, 

 Eurytoma tylodermatis, Cerambycobius 

 CYANICEPS, GlyptomorpJia rugator, G. mavaritus, 

 G. lixi, Vipio helfragei, Microdus simillimus, 

 and Horismenus lixivorus. Mr. Townsend has 

 described LixopJiaga parva from a specimen reared from this weevil 

 at Dallas, Tex., August 15, 1907. 



ERIRRHININ^. 



Fig. 20.— The blood weed 

 weevil {Lixus scrohicollis) , a 

 cohost of boll-weevil para- 

 sites. Enlarged. (From 

 Hunter and Hinds.) 



Smicronyx tychoides LeConte. This weevil breeds in stem galls of 

 various species of Cuscuta. It is parasitized by Microbracon mel- 

 litor and Eutrichosoma alhipes. 



