In this case, the subspecies you’re looking for appears on iNaturalist under the genus Cicindela as Cicindela nigrocoerulea bowditchi instead. On iNat, Cicindelidia is apparently treated as a subgenus within Cicindela, and a subgenus normally doesn’t show up in the scientific name.
However, in the future, if you need to add a new species, there are two ways to go about it. The simplest is to type the name into the ID box and then click “Search external name providers”. This can import a name from one of the taxanomic databases elsewhere on the web. If you’re going to do this, please check first whether the species you want appears on iNat under a different genus name, as it did in this case. We don’t want duplicates!
If that doesn’t work, or if you’re uncertain, you should make a Flag on the relevant taxon’s page to alert curators that something needs to be changed. I usually @-tag one or two relevant curators in a comment to make sure somebody sees it. If you’re not sure who the relevant curators are, I normally check the top identifiers for that group, and see whose profiles indicate they’re a curator.