From the following article:
http://entomologytoday.org/2014/12/2...-for-pet-food/
Due to the disease that wiped out many cricket farms a couple of years ago, several species of crickets were imported to the US. Some of the importations were illegal, and the species have significant potential of becoming invasive if released. Always ask your cricket supplier which species they breed and/or sell. Avoid all species in the
Gryllus genus.
Gryllodes sigillatus is a tropical species that is reliant upon humans, and is the best alternative to the domestic cricket,
Acheta domesticus. Some sellers may advertise all their stock as domestic crickets, so buyer beware.
Gryllus sp. crickets are very aggressive and can kill smaller lizards (a wild Mormon's cricket killed one of my steppe runners when I was a wee squeaker of a reptile owner who didn't know any better).
Please read the well-written article for more details.