Effect of seed harvesting ants on the persistence of Wimmera ryegrass in pastures in north-eastern Victoria

Abstract

In experiments at the Rutherglen Research Station in north-eastern Victoria, seed harvesting ants collected seeds of Wimmera ryegrass in preference to seeds of other pasture species. After spraying pasture with dieldrin to limit the activity of ants, it appeared that ants were responsible for the loss of appreciable amounts of ryegrass seed, and a consequent reduction in its natural regeneration. (The use of dieldrin on pastures is not recommended because of its subsequent accumulation in animal products.) It is suggested that ants may be responsible in part for the failure of Wimmera ryegrass to persist in pastures.