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New Zealand Stick Insects

Phasmatodea

Their Story

Rō, or stick insects are a fascinating group of herbivorous insects. Stick insects display a classic example of crypsis. That is, their behaviour and physiology work in tandem to remain completely undetected and unharmed. There are six species that have been detected within the Sanctuary so far, including the New Zealand giant stick insect.”

Conservation Status

All rō of Aotearoa are endemic, and though none are listed as threatened, most species have likely declined since human arrival and the subsequent loss of habitat. Additionally there may be additional pressures like rodent and vespulid wasp predation that affect populations. “

Population

Endemic to New Zealand, stick insect species are found in forested areas across the country. At Brook Waimārama Sanctuary, stick insects are regularly found.

Food

Rō feed on leaves high in the canopy of trees like kānuka. They are strict herbivores, so despite their often prickly appearance, they are completely harmless

Stick insects vary greatly in size and appearance, from small slender green forms to robust, bark-coloured adults that mimic branches. All native stick insects are flightless and have remarkable camouflage. Females are much larger than males. They will often hold their legs straight against their bodies to perfectly imitate a stick or stem.

Stick insects are generally nocturnal, moving slowly about the canopy feeding on leaves. Preferred food plants for some species are akatea – rātā vines and kānuka trees. Rō are large bodied, juicy insects and are mostly defenseless. To avoid being eaten by birds, they remain completely still during the day and rely on their camouflage to avoid predation.

Male stick insects are far smaller than females, and when breeding, the male will ride the backs of females for extended periods. Female stick insects may lay hundreds of small seed-like eggs, either on a host plant, in the ground or among the leaf litter. Some species, including the New Zealand giant stick insect, Argosarchus horridus, can lay eggs without male fertilisation. In some instances, whole populations can be made up of clones descended from a single female.

Endemic to New Zealand, stick insect species are found in forested areas across the country. At Brook Waimārama Sanctuary, the restored beech/podocarp forest and predator-free valley provide secure habitat for these elusive insects. Increased observations here help enrich understanding and appreciation of them.

All modern New Zealand stick insects are the relatives of two colonisation events from New Caledonia around 30 million years ago. They radiated into nine separate genera and dispersed into coastal, lowland and subalpine habitats, distributed across the motu.

At least six stick insect species live out their slow and sticky lives within the Brook Waimārama Sanctuary. On your visit you may find these species clinging to tree trunks or branches, If you have your eyes in! Others are very unlikely to spot as they live high in the trees. If you find an interesting stick insect, consider uploading an image to the amazing citizen science app, INaturalist so we can better understand our native biodiversity.

The New Zealand giant stick insect can grow up to 20 centimetres long! The juveniles in comparison, are generally only one or two centimetres.

Download the fact sheet PDF here

STRATEGIC SUPPORTERS

NBS-Comm-2col-CMYK-Hires (002)

CONSERVATION CHAMPIONS

Come Visit Us!

651 Brook St, The Brook
Nelson 7010
New Zealand

(03) 539 4920

info@brooksanctuary.org.nz

OPEN HOURS

Monday: Closed
Tuesday – Sunday: 9am – 5pm, last entry 4pm

The Sanctuary is open on all public holidays except Christmas Day.

PUBLIC TRANSPORT

NBus route 4 visits the Brook Sanctuary 6 days a week and departs from Nelson Airport. Click here for full timetable

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