I found many specimens, feeding on seed of grass on the side of a hurricane drain channel.
Seems to fit the information noted for the rice fields. High density of specimens especially on the edge of field grass. The density of specimens was really huge. Probably due to missing food in other area where the grass was mowed. After a while the grass was mowed alongside the channel and the bugs disappeared. I found specimens surviving on tall grass growing alongside of a fence close to this drain channel, even in December, but in more reduce number and density. I'm sure that the cause of less number is the scarcity of food for them.
On the specimens observed, a few had one tachinid egg on body.