Larvae are the most damaging stage. They are present throughout the year, but are most abundant from late autumn to early spring. Larvae live in the soil and if present, will usually be in the top 5 cm.

Development from egg to fully-grown larva varies with temperature but takes about 8 weeks. After hatching, young larvae burrow into clover nodules affecting N fixation.

CRW Larvae are 2 – 6 mm long with a brown head on a white, legless body. 

Younger larvae damage nodules leading to reduced N fixation. Biggest impact occurs during spring flush when larval numbers high e.g. 10+ larvae per spade square.

Older larvae feed on stolons and roots causing a reduction in pasture clover content and persistence. Can result in total clover loss when CRW populations are high and pasture is stressed.

1st instar larva hatching from egg.

1st instar larva inside nodule.

Mature larvae.

Feeding damage on clover nodule.

Older larvae feeding on clover stolons.