Yellowjackets

2018 was a good year for Yellowjackets, 2019 not so much.
I post my observations on inaturalist.ca

Today i did get some helpful information that i might want to look for again.

Yes, for the genus it is the shape of the head, i.e. the length of space between eyes and mandibles: https://cjai.biologicalsurvey.ca/bmc_05/bmc05images/keys/b11-3_4.jpg 
https://cjai.biologicalsurvey.ca/bmc_05/key_vespinae.html 
This is, of course, not visible here but most species can also be recognized by their abdominal patterns: 
V. alascensis (formerly vulgaris): https://cjai.biologicalsurvey.ca/bmc_05 
/98v_vulgaris.html 
https://cjai.biologicalsurvey.ca/bmc_05/85d_norvegicoides.html