Genus Rigula Day
Rigula calperum Day
Rigula Day 1999: 706. Type species: Rigula calperum Day 1999, by original designation
Known species: Three named species established by Day (1999) who also recognised one undescribed species.
Distribution: NT, Qld, SA, WA
Comments: Species of Rigula are distinguished by the presence of a vertical expansion on the posterior part of the median pronotal process (MPP). In some species, this expansion forms a distinct process (eg. R. calperum) while in others (R. naumanni, R. yalkula) the expansion is the result of a strongly sinuate upper margin of the MPP. R. naumanni and R. yalkula have the lateral pronotal processes, in anterior view, broad, apically slightly expanded, strongly longitudinally ridged and apically serrate. The genus appears to be associated with drier inland regions but the described species are rare (Day 1999) and more material may qualify this apparent association.
