A close friend of mine grew up thinking that crane flies were just male mosquitoes (and that all actual mosquitoes were thus the females). This was apparently a widespread misconception where she grew up!
A childhood belief about creepy crawlies

others believed things like this
- haha... i was around six or seven... i thought that mosquitoes grew into flies... weird..— ?!
- I used to think that a mosque was a place where mosquitoes live.Anon
- One time my brother asked my mom why mosquitoes bite. She said it was because children are bad.— sue
- I thought that a mosque (a muslim church) was a place where mosquitoes live.Anon
- A friend of mine thought that some olives grew with red edible pits (pimentos).— HA
- When I was younger, I used to believe toads were male and frog were females.— Claude-Eugène