Trying to identify a beetle seen in Ontario, Canada...and its babies, or parasites?
Thanks to pascal's answer, I looked at the genus Nicrophorus and agree that this is some member of that genus. (The spelling Necrophorus has been used in the past but is now deprecated.)  The 60+ members of this genus are commonly known as burying beetles or sexton beetles from their behavior of burying dead small animals to serve as nourishment for their offspring.
However, instead of N. vespillo, I think the species might be N. tomentosus:
(Photo: Judy Gallagher via Wikimedia Commons)
The most distinguishing feature seems to be the green or gold hairs on the thorax as seen clearly in the large version of OP's photo. These hairs or setae Wikpedia mentions as separating N. tomentosus from other members of the genus.  A common name for the species is &quot;gold-necked carrion beetle&quot;. Two other photos of this species are here and here.