Exception Can not issue data manipulation statements with executeQuery ()

I have this class called programa :

public class Programa {
public static void main(String[] args) throws SQLException{
    Persona p = new Persona("a","b","a","13-04-1994");
    String servidor = "jdbc:mysql://localhost/prueba";
    Conexion con = new Conexion(servidor,"root","");
    con.InsertarUsuario();
}    
}

and this class called Conexion :

package clases;

import com.mysql.jdbc.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class Conexion {
 private static String user;
 private static String psw;
 private static String servidor;
 private static String driver = "com.mysql.jdbc.Driver";
 private static Connection con;

public Conexion(String servidor,String user,String psw){
    this.user = user;
    this.servidor = servidor;
    this.psw = psw;
    try{
        Class.forName(driver);
        con = (Connection) DriverManager.getConnection(servidor, user, psw);
        System.out.println("Conexión correcta");
    }
    catch(Exception e){
        System.out.println("COnexión fallida");
    }

}

public void InsertarUsuario() throws SQLException{

    String sql = "Insert into prueba values(null,'borja','sanchez'";
    Statement st = con.createStatement();
    st.executeQuery(sql);
    con.close();
    st.close();


}
}

because when I run the program I get the exception:

  

Can not issue data manipulation statements with executeQuery ().

How can I solve it? Thank you very much