Section 26E. Notice of positive diagnosis received by the chief superintendent or a local superintendent shall imply necessary condemnation of said elm tree and complete removal of the tree and destruction of the wood by burning or other method to render it harmless as a future source of infection or infestation, unless the said tree or wood has ceased to be such a source of infection or infestation. Such trees or parts thereof shall be removed within thirty days of the receipt of the notice of positive diagnosis, except that when such notice is received during the months of September, October, November, December, January or February, removal may be delayed, if necessary, until a later date but not later than March thirty-first next following the receipt of the notice, but if the removal and destruction of said trees or parts thereof cannot be accomplished within the time limits herein designated for reasons beyond the control of the local superintendent, he shall by spraying or otherwise render the said trees or parts thereof harmless as a source of the spread of the Dutch elm disease infection, or as a breeding place for the beetles which spread said disease. If any city or town shall not have removed and destroyed the said trees or parts thereof within the time limits of this section or by spraying, or otherwise rendered them harmless as a source of spreading the said disease during a delay in removal and destruction of said trees or parts thereof beyond the time limits of this section, the chief superintendent may, subject to the provisions of this chapter, cause them to be so removed and destroyed or sprayed or otherwise rendered harmless as a source of the spread of said disease.