If any person summoned as herein provided shall without reasonable cause (the judge to determine what is reasonable cause) fails to appear, he may be proceeded against for contempt of court. In case the summons cannot be served or the parties served with summons fail to obey the same, or in any case when it shall be made to appear to the youth court that the service of summons will be ineffectual or the welfare of a child requires that he shall be brought forthwith into the custody of the youth court, a warrant or custody order may be issued against the parent, parents, guardian or custodian or against the child.