what do you call a female bug that floats?

What are you studying, Etymology? Surely your textbook has a glossary (dictionary) in the appendix. Try there.

Sra

a bugy ant gillant

To find the answer to your question, you can start by understanding a class of insects called water striders. Water striders are bugs that have the ability to float or walk on the surface of the water due to their unique physical adaptations. Now, if you are specifically looking for a female bug that floats, you can deduce that the term for this would be a female water strider. Since water striders are a specific type of insect that floats on water, referring to a female water strider would be the most appropriate answer to your question.