The host plant of this bug is likely to be Api-api Putih (Avicennia alba) since both adult bugs and nymphs were found on this mangrove tree. I saw a lone nymph in August 2015 at Sungei Buloh Wetland Reserve. When I made my subsequent visit in November, I got to see the adult bugs as well as more matured nymphs. However, some had already seen this bug in February 2010 (see Stomp).
In the same trip in November 2015, I came across a batch of 12 newly hatched nymphs on the leaf of Sea Hibiscus (Talipariti tiliaceum). Judging from the white line that cut across their otherwise black bodies and comparing them with the nymphs above, I believe they were the same bugs as the ones above.