Dr. Cheong Loong Fah had indicated this beetle may be a Halticorcus sp. or Argopistes sp. I had indicated it as Halticorcus sp. as there is another species in this genus, Halticorcus platycerii (Australian flea beetle), found in Australia that also feed on fern.

The pictures below showed the damages done by this beetle on its host plant, Giant Sword Fern (Nephrolepis biserrata):

The first time that I saw the beetle was in a park in 2018 but I did not know its host plant until the second sighting in 2020 in the same park. Thereafter, the fern population was removed and the beetle was gone. The most recent sighting was in April 2023 in the same park. The fern population was found growing on an oil palm tree (Elaeis guineensis).