Isodontia is a genus belonging to the family Sphecidae. Adults emerge from their cocoons in early summer, and usually make nests lined with grass or hay in hollow plant cavities. This has led to their common name being grass-carrying wasps. The larvae are often fed Orthoptera that the adult has paralyzed. Wikipedia
Thanks Zestin Soh ( Bees & Wasps of Singapore ) for the Identification.
Spotted at Windsor Nature Park