Where does “naappojain” come from?

naappojain (Ingrian) comes from Ingrian -iain, from Ingrian -in, from Proto-Finno-Ugric *-in, from Proto-Uralic -ma.

Ancestry of “naappojain”, step by step

Step	Language	Word	Meaning
1	Ingrian	-iain	Used to form nouns, especially names of insects
2	Ingrian	-in	Forms adjectives indicating the material of which something is made; -en
3	Proto-Finno-Ugric	*-in	—
4	Proto-Uralic	-ma	—