Luminary Oddities · Natural history & art
Spiny Leaf Insect
Extatosoma tiaratum
Phasmatodea / Phasmatidae
Extatosoma tiaratum is an Australian leaf-mimicking stick insect with a spiny body and pronounced differences between the sexes. Its seed-like eggs have an edible cap that can induce ants to carry them into their nests.
Read the species accountAt a glance
- Egg structure ↘
- The capitulum attracts some ant species. [3]
Identity and classification
Extatosoma tiaratum (MacLeay, 1826) belongs to Phasmatidae in Phasmatodea. The female holotype is held in the Macleay Museum at the University of Sydney. [1]
Morphology and identification
The adult female is robust and leaf-like, whereas the male is slender. Their irregular outlines and projecting spines resemble dry vegetation. Hatchlings have a contrasting red head and dark body and behave like ants before adopting the slower movements of older nymphs. [2]
Distribution and habitat
Life cycle
The egg carries a knob called the capitulum. Ants can remove and consume this cap while leaving the rest of the egg intact in the nest. The nymph emerges from the surviving egg and climbs toward foliage. [2]
Feeding and host plants
The species feeds on eucalyptus foliage. Rose and raspberry leaves have also supported captive insects. [2]
Behaviour
In controlled drop trials, first-instar nymphs steered toward vertical targets with sharp contrasting edges. They preferentially landed on narrow dark surfaces, with brightness contrast providing stronger guidance than colour differences. [4]
Distinctive biology
In one-hour trials comparing five Australian ant species, Iridomyrmex purpureus removed the most stick-insect eggs. Rhytidoponera metallica carried more Acacia seeds than eggs; the other three species removed no eggs during the trials. [3]
Artistic interpretation
Display and care
Keep the enclosure closed and display it in indirect light, away from heat and damp conditions. Handle the frame by its edges and clean only its exterior according to the maker’s instructions.
Sources and further reading
- Extatosoma tiaratum (MacLeay, 1826) ↗
Phasmida Species File · Accessed 2026-10-11
- Care of Stick Insects ↗
Australian Museum · Accessed 2026-10-11
- Ant mediated dispersal of spiny stick insect eggs and Acacia longifolia seeds is ant-species dependent ↗
Smart, Andrew and O’Hanlon; Australian Journal of Zoology 70(4), 105–114 (2023) · Accessed 2026-10-11
- Visual ecology of directed aerial descent in first-instar nymphs of the stick insect Extatosoma tiaratum ↗
Zeng, Lin, Abundo and Dudley; Journal of Experimental Biology 218, 2305–2314 (2015) · Accessed 2026-10-11
- Spiny Leaf Insect ↗
Perth Zoo, Government of Western Australia · Accessed 2026-10-11
Sources checked 2026-10-11. Illustrations · Luminary Oddities.
Return to the Entomological Atlas ↑