This species I swept from a flowering Gynotroches axillaris (a monotypic genus of trees in the family Rhizophoraceae in freshwater swamp forest) is about 6.5mm. It is quite close to Demonax latefasciata Dauber 2006 and D. longespinus Dauber 2006 but with some differences (e.g. ratio of elytra length to humeral width is only 2.8, not as elongated as the preceding two (>=3)). Suggestion of other candidates for its identity would be much appreciated.
Difficult, so many similar pattern in Demonax sp. ... Your species has the second white band as an inverted V, not an inverted T, so I do no think it is Demonax latefasciata Dauber 2006 or D.longespinus Dauber 2006. Demonax viverra (Pascoe, 1858) seeems a little bit closer to your species. Can you check it ?