Campsomeriella collaris is a wasp which belongs to the the family Scoliidae.
Scoliid wasps are a family of beetle hunters. 
They are large, rather hairy solitary wasps.
The female digs in soil, finds a beetle grub, stings it, and lays an egg on it. 
The young eats the beetle grub.

According to Gerard Schulten, a Dutch expert on Scoliid Wasp species, this is a female of the subspecies Campsomeriella collaris quadrifasciata.
The female of this subspecies is distinguished by the red-brown hairs behind the head.
For comparison, the female of the subspecies Campsomeriella collaris collaris has white hairs behind the head.

Tub Kaek Beach area, Krabi, Thailand, 4 February 2013