Grass grubs are capable of seriously damaging your lawn.

Here's a garden villain that’s dead set to bug you and foil your plans for a healthy lawn.

Number one on NZ’s ‘most wanted’ list for crimes against lawns, this little bug-er-adicates grass by feasting on grass roots and, when it matures, seriously damages shrubs and fruit trees.

Born wild:

Emerging from their eggs in summer, approximately 15-20cm below the surface, grass grub larvae feed on grass roots until mid winter, entering their pupal state from September to October.

From mid-spring until early summer these little pests are all abuzz! At this time grass grub beetles emerge ready to party. Usually on warm nights they will gather to feed on shrubs and fruit trees, find a date, mate and lay eggs.

Grub’s up?:

You will know when the young insects have been ‘larvae-ing la vida loca’ with your lawn by tell-tale patches of yellow-brown, dead grass.

White clover and ryegrass are common targets for grass grub larvae; however fruit and vegetables such as strawberries, raspberries and carrots are also at risk.

And keep your eyes on the skies. Birds find these grubs to be a tasty treat; so watch for areas of your lawn which seem to particularly attract our feathered friends.

During the spring and summer months you’ll spot evidence of grass grub beetles’ activities on bushes and trees. Check young foliage for leaf damage, paying particular attention to the grub’s favourite ‘grub’ apricot, cherry, peach, plum and apple trees. They are also quite partial to roses and grapevines.

Know thy enemy:

Growing to approximately 2-2.5cm, the C-shaped grass grub larvae are typically off-white or grey in colour. The grass grub beetles themselves are brown in colour, and grow to roughly one centimetre in length. As with many other strange creatures, these beetles usually only come out at night and are attracted by bright lights.

Although they ‘fly by night’, once these beetles are established they won’t ‘beat it’ and will be make your garden their long-term abode, unless the correct measures are taken.

We don’t need their grubby patches:

When the soil is dry during the warmer months it’s difficult to eradicate this pest as they will hibernate deeper in the earth. However, from late autumn until winter, the larvae will be closer to the surface.

Tui Products recommends using its Superstrike lawn seed range to protect against grass grubs during establishment. The Superstrike Patch Pack is ideal for repairing lawns damaged by grass grubs.

To prevent damage to plants, spray with a surface insecticide. An organic alternative, natural pyrethrum will also reduce damage to plants caused by adult beetles. Ensure this is applied in the evenings when the beetles are out and about, and the bees have flown away home.