1108 



FAMILY" I, TIT. CTIK-VS0>TT':T;II).T';. 



KKV TO INDIANA CiKNKKA OF SAGKINI. 



a. Thorax soiucw Iiat hcll-shaiK-d. the sides umcli romiilecl. without teeth 

 or tuberrle; front coxa' not i)romiiient, separatetl. III. Orsodacna. 

 aa. Thorax with a tul)ercle or anguhite at the sides; front coxte prominent, 

 conti^nious. 

 ft. Eyes eniari,nnate; thorax with a laruce. distinct tubercle on sides; 

 front coxal cavities closed; claws toothed. IV. Zeugophora. 



?>?>. Eyi's entire: thorax angulate or toothed at sides; front coxal cavi- 

 ties open ; claws cleft. V. Syneta. 



III. Orsodacna Lat. 1802. (di-., "Inid 4 gnawer.") 



This genus, as eliaracteri/.ed al)ove, contains a single speeies of 

 such variability in color, that it has heen described under six or 

 seven different names. It ocetirs on willow 1)1ossotiis in the spring, 

 several color varieties often being found on the same tree. All in- 

 tergrades are known, from those eiitirely pi<'eous to those almost 

 wholly pale brownish-yell o^^^ 



Fig. 477. X 4i 

 (After Wiclsham.) 



2041 {(\'>7>0). Orsodacna atka Ahrens, Nov. Act. Ilaleus, 

 I, 1810. 4G. 

 Elongate, rather slender, subconvex. Color given in 

 varietal key below. Antennae less than half the length 

 of body, the joints subequal in length, bell-shaped, much 

 narrowed at base. Thorax longer than wide, distinctly 

 narrowed behind the middle; surface coarsely, roughly 

 and rather sparsely punctured. Elytra one-half wider 

 than thorax, coarsely punctate, tips rounded. Length 4- 

 7 mm. (Fig. -177.) 



KEY TO color VARIETIES OF O. ATRA. 



a. Elytra wholly blackish or piceous. 

 h. Thorax black or piceous. 



c. Legs wholly piceous. atra Ahr. 

 cc. Tibife and femora brownish-yellow. tibialis Kirby. 



bJ). Thorax more or less reddish. 



d. Thorax reddish with central dark spot. luctuosa Lac. 

 dd. Thorax entirely reddish-yellow. hepatica Say. 



aa. Elytra more or less brownish-yellow. 

 c. Elytra with stripes. 



/. IMceous, thorax reddish-yellow; elytra each with one yellow stripe 



on disk. vittata Say. 



//. r>ull yellow; elytra each witli sutural line and stripe on side dark. 



thivittata Lac. 

 ec. Elylra dark, with large hmneral and apical yellow spot. (Fig. 477.) 



chilureni Kirby. 



