Physomerus is a genus of true bugs in the family Coreidae, subfamily Coreinae, tribe Acanthocorini; containing the notable pest species Physomerus grossipes (Fabricius, 1794). The genus was erected by Hermann Burmeister in 1835. Wikipedia
Spotted at Choa Chu Kang
Thanks Chace Foo Maosheng for the ID https://www.facebook.com/groups/sginsectid
