4 occurrences in 4 dictionaries

Reference: Susanchites

Easton

the inhabitants of Shushan, who joined the other adversaries of the Jews in the attempt to prevent the rebuilding of the temple (Ezr 4:9).

Fausets

Ezr 4:9-10. Descendants of some of the nations planted by Asnapper in Samaria. Inhabitants of Susiana or Susa.

Morish

Susanch'ites

Persons whom the Assyrians imported into Samaria. Ezr 4:9. They are supposed to have been from Susa.

Smith

Su'sanchites

is found once only --in

Ezr 4:9

There can be no doubt that it designates either the inhabitants of the city Susa or those of the country --Susis or Susiana. Perhaps the former explanation is preferable.