MELANOTUS — QUATE AND THOMPSON 



11 



Pronotal punctures subequal in size to those on front; elytron usually 

 more than 8 mm; cf aedeagus often with convergent sides and tapering 



to tip 18 



17(16). Antenna same color as head and thorax; cf paramere evenly tapering to 

 apical blade; outer margin of apical blade nearly straight . 9. verberans 



Antenna usually lighter in color than head and thorax; cf paramere 

 with marked constriction at base of blade; outer margin of blade 



rounded 10. emissus 



18(16). Male aedeagus broad until near apex and then abruptly tapering to 

 apex; spines of 9 bursa confined to basal third 19 



Male aedeagus slender and evenly tapering from base to apex; spines of 



9 bursa in center , 20 



19(18). Pronotal punctures large and separated by less than own diameter; 

 dark reddish brown to black species; spines of 9 bursa without large 

 base (fig. 8b) ; d^ genitalia as in figs. 4a-d 1. similis 



Pronotal punctures smaller and central punctures separated by own 

 diameter; reddish-brown species; spines of 9 bursa with large, plaque- 

 like bases (fig. 9c) ; cf genitalia as in figs. 4j-l 8. miscellus 



20(18). Male genitalia as in fig. 4j 5. communis 



Male genitalia as in fig. 4k 6. indistinctus 



Male genitalia as in fig. 41 7. dietrichi 



Americanus Group 



(Mandible with pit on lateral margin) 



21(4). Antennal segment 3 small, subequal to 2 (in doubtful cases of some 



99, 3 less than VA length of 2) 22 



Antennal segment 3 intermediate in size between 2 and 4, clearly larger 

 than 2 (in doubtful cases of some 99, more than 1}^ length 



of 2) 27 



22(21). Small species, elytron less than 6 mm 23 



Larger species, elytron more than 6 mm 24 



23(22). Pronotum wider than long; pronotal punctures smaller than those on 

 front and sparse, widely separated, equal size throughout; East 



Coast to Nebraska 32. americanus 



Pronotal punctures coarse, larger than on front on anterior two-thirds 



and fine, sparse on basal one-third in cf ; Southwest . 36. concisus 



24(22). Antenna exceeds tip of hind angle by 1-4 segments; parantennal fovea 



large; flagellar segments elongate 25 



Antenna of cf barely exceeds tip of hind angle, 9 antenna shorter; 

 parantennal fovea, clearly smaller than antennal segment 2; flagellar 

 segments triangular, not elongate; pronotal punctures large and dense; 

 cf paramere with pecuhar, winglike flaps near center; Texas. 



38. hamatus 



25(24). Elytron length 6-8 mm 26 



Large species, elytron 8.5-11.5 mm; nasale quadrate, about as wide as 

 high; antenna exceeds tip of hind angle by about 2 segments; cf para- 

 mere with definite apical blade and antennal hairs long and dense. 



19. corticinus 

 26(25). Antenna very long, exceeds tip of hind angle by 2-4 segments; sides of 

 pronotum divergent posteriorly; nasal narrow, higher than wide. 



33. cribriventris 



