Originally Posted by Analise
It sounds like they are impeding on interstate commerce by these "inspections".
No, not at all, they're just protecting California commerce (agriculture) from infestations.
Analogize to the myriad of state laws we have about truck weights, and the weigh stations truckers have to go through pretty much any time they enter every state -- protecting the roads of that state. Same principle. I'm sure there are many other analogies.