I don't think every Digimon needs a dedicated evolution meant specifically for them
but I think too many gen 1 champion level Insect Digimon have to share Okuwamon and Megakabuterimon ( both versions) as an Ultimate level which are heavily connected with their own canon Digivolutions. for other insect options they have...
Dinobeemon but its design is heavily tied to Stingmon and X-Veemon fused together and being a fusion in general
Jewelbeemon also feels like it is meant to be an ultimate level specifically of Stingmon.
Scorpiomon has an exoskeleton but it is not an Insect or a scorpion but thats another issue
Arukenimon does a spider lady count? that being said I like this evolution better than some of the other especially for lines that start with Kunemon or Dokunemon.
In Short I think there is a shortage of ultimate level insect digimon.