>>54162371This.
Let me explain this for people who do not understand things about Moths and Butterflies.
>WingsButterflies fold their wings vertically (which both Butterfree and Venomoth do), Moths fold them down to hide their abdomen.
>AnatomyMoths have wing frenelums, which are hard to tell when it comes to Pokemon designs of course. So we'll skip this one.
>BehaviorMoths are typically nocturnal, Butterflies are typically diurnal. This means nothing in Pokemon, as you can find both during each, and there are Butterflies and Moths that are the opposite.
>Cocoons/ChrysallisThis is largely irrelevant since Venonat doesn't have a middle stage.
>AntennaeMoths typically have fuzzy antennae, but this is not the case in a lot of North American species, they have thinner antennae typically. Venomoth's antenna are very thick and not fuzzy at all.
Considering the name of Venomoth being Morphon and Morpho being a genus of Butterfly, it's safe to assume it's based on a butterfly. The only logical assumption of Venomoth being an actual moth is Venonat being potentially based on a Puss Caterpillar. Which I'd argue that Larvesta is closer in design to a Puss Caterpillar than Venonat is.