There are no "new" strains of B. Dubia within the united states, as all current breeding stock has originated from the same imports. Regardless of who you order from, your not getting any new genetics. Also, some of you might be suprised just how little diversity there is when it comes to breeding tropical roaches, especially B. Dubia. If you were to work hard enough, you can trace all current colonies back to the original suppliars regardless of who you buy from. Where do you think new roach suppliars get their colonies? They don't import them, thats for sure.
This is true for most any non-native tropical roach species. I should say, it isn't necessarily a bad thing, as roaches being rather simple creatures can be bred for many thousands of generations with no new genetic input. Anyone buying roaches should be more concerned about husbandry practices, and cost than genetic diversity.