The state Department of Agriculture says nine coqui frogs were captured on Oahu this month.

Several of the invasive frogs were found at plant nurseries in Waimanalo and Kaneohe. Two others were found in the same residence in Kalihi where officials captured one coqui last month.

In Waipahu, department officials captured one after a resident used her cell phone to record its mating call. This made it easier for authorities to confirm the frog was a coqui.

Coqui frogs reproduce quickly in Hawaii because they don’t have natural predators here.

The frogs are well established on the Big Island. Many have been showing up on Oahu after hitchhiking their way in plants and other cargo.