Looking at the list of bugs, the Orchid Mantis is actually a "C" tier bug, but you likely got a really big one. I have my bugs all sorted out by the order I want to turn them in.
For E rank, got a few wharf roaches, a ton of Fruit Beetles, then some Common/Yellow Butterflies.
For D Rank, I have Tiger Butterflies, Darner Dragonflies, and Fireflies.
For C Rank, I have an Emporor Butterfly, some Laturn Flies, Horned Dynastids, a Miyama stag.
For B Rank, I have Cyclommatus Stag, Goliath Beetle, and Horned Elephants, and a Birdwing Butterfly.
Didn't find any A rank stuff, but I'm sure something from B could get 100 points. I may hold onto the bulk of my B bugs to just sell off if I can get something high in the first few attempts.