93 



Acoma shares 22 apomorphic character states of the wing articulation and wing base with 

 Orphninae, Melolonthinae, Rutelinae, Dynastinae, Cetoniinae, Oncerinae, Chasmatopteri- 

 nae, Hopliinae, Trichiinae and Valginae (Browne 1993). 



Chasmatopterinae 



Introduction 



Chasmatopterinae is a poorly defined subfamily but there is little doubt that it is one of 

 the more transformed scarab subfamilies closely related to Melolonthinae (Horn 1867; 

 Saylor 1937; d'Hotman & Scholtz 1990a,b). Chasmatopterines were removed from 

 Melolonthinae and elevated to subfamily status based on the position of the adult 

 abdominal spiracles of the 7th and 8th segments in the pleural membrane (Saylor 1938), 

 but Ritcher (1969a,b) found that these spiracles are situated in the lower parts of the 

 tergites. However, chasmatopterines are more commonly considered to belong to either 

 Chasmatopterini (Leng 1920; d'Hotman & Scholtz 1990a) or Melolonthini (Nel & Scholtz 

 1990). 



Hind Wing Articulation Description 



First Axillary (Fig. 150) 



Head - Dorsal surface strongly reduced posteriorly; broad; weakly clavate; convex. Antero- 

 dorsal margin oriented weakly postero-distad; normal width; very convex. Antero- 

 proximal margin with ventral enlargement reduced. Postern -proximal margin enlargement 

 moderate and broad. FSc2 base weakly enlarged; deeply concave. Apex oriented postero- 

 distad; rounded but narrowly so. Anterior surface narrow; long; waisted medially. FScl 

 absent. Ventral projection long and narrow; enlarged mesally; deeply concave; oriented 

 ventrad and weakly postero-distad. Dorsal surface base to median concave. Ventral surface 

 convex. Apex wider than base; strongly flared; truncate. Concavity basad and moderately 

 extended apicad from the base of the ventral projection; surrounded by three unequally 

 strong ridges. Distal embayment oriented ventro-mesad. FSc2 oriented distad and weakly 

 dorsad; deltoid; convex; broad; moderately short. Dorsal surface enlarged dorsally; convex; 

 appears twisted. Ventral surface convex. Base proximally with a large convexity. Apex 

 aciculate. Head and neck dorsal surface extended anteriad. 



Neck normal width; long; weakly oriented antero-distad; articulation with 2Ax extends 

 along the distal margin of the neck and tail; continuous with tail. Proximal margin reduced; 

 sinuate; not curved ventrad. Distal margin concave. Distal embayment moderately concave; 

 moderately shallow but broad. 



Tail - Dorsal view: Proximal arch normal size. Dorsal surface weakly concave. Antero- 

 proximal margin weakly convex. Po stem -proximal margin straight. Articulation with PRR 

 strong along the entire length of the proximal arch; very long but narrow; weakly recurved. 

 Antero-dorsal surface concave. Postero-dorsal surface concave. Posterior margin weakly 

 concave. Distal arch normal size. Apex weakly curved posteriad and ventrad; aciculate. 

 Distal margin weakly concave. - Ventral view: Proximal arch with a weak and very slender 



