Tetrix transsylvanica, the Transsylvanian wingless groundhopper, is a species of insect in the family Tetrigidae. It is found in Romania and Slovenia and was until recently thought to be extinct in Croatia, only for a large population to be found at Siljevec on Ivanà ¡ÃÂica and small populations on StrahinjÃÂica, Medvednica and Zelniska gora.