Key to the Subgenera of Rhyzodiastes


1.      Each compound eye divided into two ocellus-like structures; 
        elytron with intercalary stria present (three striae medial 
        to subapical tubercle). .....................R. (Rhyzotetrops)


1'.     Compound eye entire, crescentic or hemispherical; 
        intercalary stria absent (two or one stria medial to 
        subapical tubercle). ........................................2

2(1).   Paramedian grooves closer together at middle of length than 
        at base or apex; outer carina much wider at middle than at 
        either end; tufts of minor setae on antennal segments VII-X. 
        ................................................R. (Rhyzoarca)


2'.     Paramedian grooves not closer together in middle than at 
        either end; outer carina not much wider at middle than at 
        ends; tufts of minor setae on antennal segments IV-X, V-X, 
        or VI-X. ....................................................3

3(2).   Inner carina of pronotum with lateral margin as distinct as 
        medial margin; inner carina abruptly separated from 
        paramedian groove, which is entirely pollinose. 
        .....................................R. (Rhyzodiastes s. str.)


3'.     Inner carina with lateral margin sloped gradually into 
        paramedian groove; paramedian groove in most species with 
        pollinosity limited to its border with outer carina 
        (R. pollinosus is an exception). ..........................4

4(3).   Eye enlarged, hemispheric; gena with curved band of 
        pollinosity below eye; basal margin of pronotum with narrow 
        strip of pollinosity. .........................R. (Rhyzostrix)


4'.     Eye narrow, crescentic; gena below eye glabrous; basal 
        margin of pronotum not pollinose. ................R. (Temoana)