"The strange frequency of Dragons/"dragons" with insect-like lifecycles"

In a thread about adding secondary types to Pokemon, /u/SidewaysInfinity raised something which I'd never thought of before:[Flygon is] one of many "dragons" in Pokemon that seem to be reptiles with a very insect-like life cycles, along with Dragonite, Salamence, Tyranitar (not a dragon but a kaiju that pupates), etcI'd never thought of it before, but it's true!Flygon famously mimics an antlion lifecycleSalamence emerges from a Shelgon pupaTyranitar (not a Dragon-type, but dragon-like) emerges from a PupitarGoodra are based on slugs and snails (not technically insects, but also creepy-crawlies)Given the Dragon-type is a fairly rare one, to have three of its three-evolution families based on insects/gastropods seems unusually high. Do people have an insight into why this might be? Is it based on something in Japanese culture or mythology? via /r/pokemon http://ift.tt/2w7NPsn