AgPest Alert: 1 February 2021

Argentine stem weevil is a significant threat to seedling grasses

Region: All of NZ

Argentine stem weevil is a significant threat to seedling grasses, even those infected with endophyte, at this time of year. This also applies to cereal and maize crops. If it is possible, delay sowing until early March when much of this threat will have passed. See DairyNZ Pasture Renewal Guide for endophyte selection.


In the northern North Island damage from black beetle larvae may be showing

Region: Northland, Auckland, BoP, Waikato

In the northern North Island damage from black beetle larvae may be showing. Unfortunately little can be done to prevent this. Adults are deterred by AR37, Endo5 and NEA2 endophyte- infected grasses which will reduce egg laying and larval numbers. See DairyNZ Pasture Renewal Guide


Second porina flight due

Region: Bay of Plenty, Waikato, Gisborne, Hawkes Bay, Taranaki, Manawatu Wanganui, Wellington, Nelson Tasman, Marlborough, Canterbury, West Coast,
Otago, Southland

The early flight of porina moths has passed but the second flight significant flight is about to occur in the South Island and could take place anytime between now and the end of February. Further flights may occur in March in the North Island. In areas that experienced an early (October/November) porina flight mid January to mid February is the optimal time to be applying diflubenzuron.


Ordering grass seed? 

Region: All of NZ

When ordering grass seed select suitable endophytes and check that the endophyte you select has been assessed in the grass variety you order. In ryegrass, AR1 and AR37, and and diploids with NEA2, will protect against Argentine stem weevil, AR37, Endo5 and NEA2 against black beetle and AR37 against porina. See DairyNZ Pasture Renewal Guide for a guide to endophyte selection.

Endophyte levels in the seed should be at least 70% and have been assessed in the last 3 months.


Wanting to control Californian thistle?

Region: All of NZ

Mowing Californian thistle during rainfall can improve control of this weed by 30% as compared to mowing during dry weather. Best time to do this “wet mowing” is in February/March when the fungi thought to be responsible for this effect are producing spores on the thistle. The effect is likely to be greatest if some members of the thistle population to be mowed are showing signs of disease (wilting, yellowing, dieback).


Watch for Tasmanian grass grub beetle flights.

Region: Gisborne, Hawkes Bay, Canterbury, Central Otago

Watch for Tasmanian grass grub beetle flights. Beetles are attracted to lights at night. Large numbers of beetles flying may indicate potential damage from the larvae in autumn and winter.

Social tagging: > > > > > >

Comments are closed.