Casual Observation or Not?

As mentioned by neylon, this would be a “normal” observation, that means an observation of a wild organism, at your house. I would still recommend to additionally write in the comments and/or observation fields where you found it in (a package of dried popcorn kernels), the origin of the produce (where it was grown, normally it is stated on the package). It may not be possibly, where the insect moved into its new home (at the packaging facility, supermarket or your home), but teh narrow it down a bit the information if you found it just after opening the package would be helpful, too.