Rutherglen Bug

The adult Rutherglen bug is a slender, greyish-brown insect about 4-5 mm long with a narrow, elongated body and clear wings held flat over the back, giving a mottled grey-brown appearance. It is an active flier and can be seen running rapidly over foliage and flowers, especially when disturbed. Nymphs are wingless, smaller, and range from pale grey to reddish-brown as they mature, with a more rounded, soft-bodied appearance; they cluster on leaves, flower heads and developing seed pods, often in large numbers.

Rutherglen bug is a native Australian pest that builds up on inland weeds and pasture, particularly capeweed and other broadleaf weeds, over spring. As these host plants dry off or are cut, large populations migrate on warm northerly or westerly winds into cropping and horticultural districts, sometimes arriving in sudden, dense swarms.

It is a generalised feeder, attacking a wide range of hosts including vegetable seedlings, ornamentals, fruiting crops, nursery stock and some turf species, particularly during warm, dry spring and summer periods. Both adults and nymphs feed by piercing plant tissue and withdrawing sap, favouring soft new growth, flowers, developing seed and fruit.

Management relies on monitoring for migratory influxes, particularly after warm dry spells following rain, and inspecting susceptible crops closely during flowering and fruit set when damage potential is highest. Reducing weedy host plants such as capeweed around production areas, and maintaining plant vigour to help tolerate light feeding pressure, are useful cultural measures. Because populations can arrive suddenly in large numbers and move on quickly, timing of control action is important.