The animal health and welfare issues created by the expression of ergovaline and lolitrem B led to the search for Epichloë strains that did not express these alkaloids but were still able to provide the grass plant with resistance to major pasture pests.
In New Zealand, during the 1990s, this was Argentine stem weevil and the endophyte released commercially to provide resistance while not causing ryegrass staggers was AR1. AR1 associations produce peramine but do not produce lolitrem B or ergovaline. However, while effectively controlling Argentine stem weevil and pasture mealy bug, AR1 has only a moderate effect on African black beetle. AR1 can also be more susceptible to root aphid when compared to the same ryegrass germplasm without endophyte.
Ryegrass varieties with AR1 can be purchased from all good seed retailers.