Insect gears

Insect gears---where are they. I can only find 2

There's a number of forum posts about people only having received two insect gears unfortunately!:/
I've played the game perfectly only to discover myself needing the three insect gears and still only having two even though I did everything that should have given me the three of them.
I'm not happy!:(

The third one is actually the first one you missed. At least it was in my case. When you go out the back door of LeGrandes house towards the barn. Give the handkerchief to the dog. He will go dig up the gear.