BioShield® Grass Grub Liquid

Biocontrol for safe, effective grass grub control

Excessive grass grub numbers in pasture, orchards or vineyards can damage the roots of plants. In new grape plantings, for example, grass grub larvae can cause significant vine deaths in the first few years.

BioShield Grass Grub Liquid is a long-term grass grub control solution that works by introducing a disease that is specific to grass grub larvae, which is then passed from dead grubs to following generations.

Used correctly, the grass grub control timeline will include:

  • 6 weeks – approx. 10–20% of grass grub show signs of amber disease (specific for grass grub larvae only).
  • 1 year – the grass grub larvae population should be approx. halved from time of application. Dead grass grub larvae will not be visible as they decay quickly.
  • BioShield Grass Grub Liquid provides approx. 3–5 years’ protection, depending on environmental conditions.

BioShield Grass Grub contains the active ingredient Serratia entomophila, a soil bacterium that occurs naturally in New Zealand which causes amber disease in grass grub (Costelytra zealandica).

BioShield Grass Grub liquid starts the amber disease cycle in NZ grass grub larvae leading to a population decline process that includes:

  • The liquid is applied to the soil and is ingested by grass grub larvae, which take in the soil while feeding on plants and roots.
  • Once inside the grass grub gut, the Serratia entomophila bacteria multiply and cause amber disease. As a result, the grass grub stops eating within 3 days.
  • When the infected grass grub dies of starvation and decompose, the Serratia entomophila bacteria in their gut is released into the soil and ingested by other grass grubs.
  • The cycle of infection is now set up for long-term control of the grass grub. 

BioShield Grass Grub liquid is safe for humans, stock and other insects.

Registered pursuant of the ACVM Act 1997 No. P4409 

Directions for use:

Check out our grass grub vineyard control brochure here.

Maximising the activity of BioShield® Grass Grub Liquid

  • Soil moisture content must be above 15-20% before applying BioShield® Grass Grub Liquid on to soil. Irrigate after application if required.
  • Apply in 1,000 L of water. Co-apply BioStart Digester at 4 L/ha to enhance the establishment of BioShield Grass Grub Liquid in the soil.
  • Do not apply after April as the grass grub larvae will have usually developed beyond the susceptible stages by this date.

Post-treatment management – Do not use:

  • Alternative grass grub control practices such as heavy rolling or insecticide treatments after application as this will reduce the effectiveness of BioShield® Grass Grub.
  • Cultivation following treatment as it is likely to reduce the effectiveness of BioShield® Grass Grub.

It is an offence to use this product on animals.

BioShield® Grass Grub Liquid must not be applied directly on to or into water.

Withholding period: Nil

Compatibility: Call BioStart 0800 116 229 for a compatibility list.

User Rate Application Timing
Apply BioShield® Grass Grub Liquid at 1 L/ha as a subsurface application to actively feeding grass grub larvae. Dilute BioShield® Grass Grub Liquid in 100 L/ha of unchlorinated, clean water prior to application. Apply via a liquid applicator fitted to a seed drill (e.g. triple disc or direct drill) to a depth of 10–30mm below soil surface. Apply to actively feeding grass grub larvae when they are in the late second to mid-third instar stage of development. This stage occurs between February and mid-April.

Material Safety Data Sheet

View here

Label information

Download the product label here.

Handling precautions

Avoid skin contact and inhalation of spray mist. Wash hands and exposed skin before meals and after work. Store in the original packaging, tightly-closed away from children. Do not store diluted product.

It is an offence to use this product on animals.

BioShield®Grass Grub Liquid must not be applied directly on to or into water.

Storage instructions

Store under refrigeration (4 °C) at all times prior to application. Exposure to sunlight or warm temperatures will reduce viability. Keep out of each of children.

Empty container disposal

Triple rinse and return to an approved AgRecovery recycling centre.

Label information

Download the product label here.

Empty container disposal

Triple rinse and return to an approved AgRecovery recycling centre.