Need help to identify this tiny bug worm

[Patricia R-Miles]

Hi there, after visiting Waiheke Island i found this little bug looks like a cone shaped shell 2mm long (very small) under 30x magnification casing has flakes of wood looking material, the larger end has a caterpiller? type worm with silky surround inside shell very hard to see even under 30x magnification so any help to identify this looks like a bagworm but not sure due to size photo added

[Murray Dawson]

Have you posted your image on NatureWatch NZ itself (http://naturewatch.org.nz)? This forum is for technical issues and that sort of thing, so is seldom visited by our community of identifiers. Thanks!