Wasps can also be said to symbolize the fundamental unity of being, a core component of Hindu teaching. Hindus believe that all living things, including wasps and human beings, are all ultimately one. We mistake the world around us, the world of multiplicity, as the real world, when in fact it's nothing more than a veil that hides the oneness of the universe and everything in it.

Mrs. Moore comes to see this for herself in the remarkable epiphany she experiences when she watches the wasp buzzing about her room. Professor Godbole incorporates the wasp, this most lowly of creatures, into his cosmology of divine love. This universal love is so vast and overflowing that it embraces every living thing, from the highest to the lowest. On a more worldly level, the wasp can also symbolize the possibility of India, with its multiplicity of castes and religious practices, recognizing its own unity as a nation and forging ahead in its movement towards independence.

The wasp symbolizes India itself.  Mrs. Moore admires the wasp for its beauty, especially since it is such an Indian wasp and not at all British.  However, she completely underestimates or ignores its power to sting. 

In the same way, she admires India's beauty, forgetting that this is a country desperately trying to survive and keep its own identity.  That beautiful "sting" will eventually be aimed at the British raj, as she finally understands at the end of the story, as she leaves to return to England.