Bug FAQSmooth Stick Insect
Clitarchus hookeri · Order: Phasmida · Family: Phasmatidae
Also called: Common Stick Insect, The Common Stick Insect
The smooth stick insect is a large species, with females reaching about 8 to 10 cm and males about 6.5 to 7.5 cm in length. It is usually green but can also appear brown or red, and this colour variation is genetic rather than caused by the environment.
Source: Wikipedia
How to recognize it
Adults are commonly green, though brown and red forms also occur, and the colour is determined by genetics.
Source: Wikipedia
Size
Females grow to 81 to 106 mm and males to 67 to 74 mm.
Source: Wikipedia
What it eats
Females hang from branch edges and eat the leaves of their host plant.
Source: Wikipedia
Life cycle
They develop through six nymphal instars before the final molt to adulthood. Parthenogenetic females often refuse to mate in captivity, while males cannot tell sexual from parthenogenetic females.
Source: Wikipedia
When you see it
Adults appear in summer and are mostly active at night. Females signal males by releasing volatile chemicals while feeding on leaves.
Source: Wikipedia
Where it comes from
The species originated in New Zealand.
Source: Wikipedia
Lookalikes
It is one of three stick-insect species that have become naturalised in Great Britain, alongside the prickly and unarmed stick insects.
Source: Wikipedia
Where it is found in the US
Recorded in 1 of 51 states and DC. Most records: Illinois.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
More photos
Questions people ask
How big does a smooth stick insect get?
Females reach 81 to 106 mm and males 67 to 74 mm in length.
Source: Wikipedia
What colour are smooth stick insects?
They are usually green, but can also be brown or red, a trait set by genetics.
Source: Wikipedia
What do smooth stick insects eat?
Females feed on the leaves of their host plant while hanging from branch edges.
Source: Wikipedia
Same family (Phasmatidae)
Margin-winged Stick InsectCtenomorpha marginipennisDamages trees, gardens or crops
Prickly Stick InsectAcanthoxyla prasinaDamages trees, gardens or crops
Spur Legged PhasmidDidymuria violescens
Spiny Leaf insectExtatosoma tiaratumCan irritate skin
Titan Stick InsectAcrophylla titan
Unarmed stick-insectAcanthoxyla inermisSources
- Wikipedia: https://en.wikipedia.org/wiki/Clitarchus_hookeri
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.