Create node with taxonomy field using services in drupal 7 I am creating node from my android app using services 3. I hit this URL www.mysite/endpoint/node with the following json:

{
    "title": "my act for tax",
    "type": "activity",
    "field_activity_type": [{
        "tid": {
            "tid": "[tid:45]"
        }
    }]
}


field_activity_type is a taxonomy term autocomplete filed. 

Node is created successfully but field_activity_type remains empty. I am unable to find a correct way to populate taxonomy field. 
Anyone who knows please help me.
Here is the Json format to create node having taxonomy filed

{"title":"my act for tax","type":"activity","field_activity_type":{"und":"termname"}}