It is an Hemipteran Fulgoroidea photos of collections lead to Eurybrachis but you should search scientific descriptions and compare these with your specimen.
We placed in 2009, in the internet about another species of Eurybrachidae from Thailand entitled "Observations on some behaviours of Ancyra vicina Lall. in North Thailand (Homoptera, Eurybrachidae)". This short film on the behaviour may be interesting for you.