Description
Mānuka chafer beetles are a native scarab beetle that grow up to 10 millimetres in length. Most commonly they are a bright iridescent green but can be bright pink, copper or blue.
Beetles fly during the day and can form swarms in hot weather. Beetles are only present for a few weeks in late spring or early summer. During this time, they mate, and females lay their eggs in soil. Larvae are soil-dwelling. They are grey-white coloured grubs with tan heads. They are about 10 millimetres long and can be found in soil laying in a C-shape. They look like grass grub larvae but are usually smaller. Larvae feed on the roots of many pasture and weed species and can cause pasture damage. They also feed on the roots of mānuka
Common native plant hosts
| Scientific names | Māori/common names |
|---|---|
| Kunzea ericoides | Kānuka |
| Leptospermum scoparium | Mānuka |
Scientific names
Kunzea ericoides
Māori/common names
Kānuka
Scientific names
Leptospermum scoparium
Māori/common names
Mānuka
Symptoms and damage
- Adult beetles feed on the young foliage of mānuka, kānuka and other native species.
- Larvae will feed on roots of pasture, weeds and mānuka.
- Considered a minor pasture pest but can cause damage when populations are high. Populations are estimated by digging at least 10 spade squares (holes that are 200 by 200 millimetres wide and 100 millimetres deep) per paddock and examining the soil for grubs. Averages over 12 larvae per spade square (300 larvae per square metre) can cause pasture damage.
Prevention and control tips
Chemical control in pastures where the larvae are causing damage.