Each association shall provide and maintain a fidelity bond covering its officers, attorneys, employees, agents and directors when performing the duties of officers or employees, in the form and amount required by the commissioner, but in no event less than One Hundred Thousand Dollars ($100,000.00). No bond coverage will be required of any agent which is a financial institution insured by the Federal Deposit Insurance Corporation. Such bonds shall provide that a cancellation thereof either by the surety or by the insured shall not become effective unless and until thirty (30) days' notice in writing first shall have been given to the commissioner, unless he shall have approved such cancellation earlier.