Key to species (5) of D. exigua species group
1 Elytra with short, spatulate, flattened setae (Figs. 1 Fa, 1Ga)...................... D. himerensis (Bellò & Baviera, 2011)
1’ Elytra with widened or clavate, recumbent, raised, semi-erect setae (Figs. 1 Fb–d, 1Gb–d)............................ 2
2 Elytral declivity with more elongate and semi-erect setae (45°–75°).......................... D. exigua (Stierlin, 1861)
2’ Elytral declivity with less elongate and recumbent, raised setae (15°–45°)......................................... 3
3 Recumbent setae on elytral declivity; elytra without humeri....................... D. trinacriae (Bellò & Baviera, 2011)
3’ Raised setae on elytral declivity; elytra with humeri.......................................................... 4
4 Elytra with more raised setae (40°–45°). Rostrum with epistome................................ D. margheritae sp. n.
4’ Elytra with less raised setae (30°–40°). Rostrum without epistome.................................. D. genistae sp. n.