This disclosure provides to a new tall fescue grass endophyte (Neotyphodium coenophialum) referred to as 647, as well as to synthetic combinations of the 647 endophyte and tall fescue grass plant or tall fescue grass cultivar. This new endophyte does not produce detectable ergovaline or any other ergopeptide alkaloids which are known to be harmful to grazing livestock. Thus, the 647 endophyte can be used in combination with forage grasses. In addition, the 647 endophyte provides increased green matter yield and improved resistance to black beetles (Heteronychus arator) and other pests. Thus, the 647 endophyte can be used in combination with grasses susceptible to infection or infestation with black beetles.
