you don’t need to add individual species. you can just add a high level taxon like Nepomorpha to your project criteria, similar to what this project has done: https://www.inaturalist.org/projects/water-bugs-of-south-australia-nepomorpha?tab=about.
if you’re talking more about aquatic insects in general, then you can look to see what other projects have added to their project criteria: https://www.inaturalist.org/search?utf8=✓&q=aquatic+insects&commit=Go&source[]=projects.