Clover-friendly pasture management is important as healthy clover can better withstand CRW. Populations vary with seasons and years. Climate variables within seasons can also impact on CRW numbers. Use of the following strategies can manage CRW population to minimise loss of farm profitability:

Spring

Adult CRW are starting to emerge from the soil from October onwards. Notching on the clover leaves is more obvious. The adults are laying large quantities of eggs into the pasture.

• Don’t let a pasture get rank – shielding clover from the sunlight reduces its ability to grow and contribute to pasture production.
• If you see a lot of feeding damage, consider increasing the N inputs over this period to take advantage of the better growth conditions.  This will also counteract losses from poor N fixation due to larvae feeing on nodules.
• The presence of nematodes and CRW mean that spring sown clover will generally fail. A spring crop (maize or brassica) prior to autumn pasture re-establishment may lead to better clover establishment. 

Summer 

Adult egg laying and egg and larval survival are dependant on summer rainfall. During a dry summer CRW populations do not build up as the heat and dry conditions reduce egg laying, decimate eggs laid and numbers of young larvae. This can lead to low populations the following autumn and clover resurgence. During wetter summers when the soil moisture levels are maintained, CRW survival is good. This can lead to high populations in autumn. 

•  Keep sufficient cover on pastures to protect the vulnerable clover stolons from direct sunlight.
• Reduce N applications particularly if conditions are dry.

 Clover in a pasture does not necessarily mean you will be getting N fixation.

Autumn

Initially CRW larval populations decline as they pupate and new adults emerge. Egg laying rapidly increases and larval populations begin to rise. Following a moist summer when CRW larval populations were very high, clover plants will still be under stress.

• Avoid over grazing pasture.
• Apply N in autumn once soil moisture is high to grow grass for winter.
• If sowing clover into a CRW-infested pasture, it is likely that CRW adults will need to be controlled to ensure good clover establishment. One way to do this is through pasture renovation.  Sowing into a pasture that has had a break-crop such as maize or turnips will help provide a pest-free start.

Winter

In winter you will see less adult CRW damage; however, larval numbers are at their highest at this time of year.  This is a problem because larvae cause ‘invisible’ damage underground which will impact pasture production the following spring.

Winter larval numbers are greatest if the previous summer was moist and clover levels were good. This supports large adult populations and protects eggs from desiccation so greater numbers of larvae hatch.

Avoid pugging at all costs as it compacts the soil affecting future pasture yield.  Building pasture cover leading into the wet season can help.