Stick insects

Definition

Members of the insect order Phasmatodea, characterized by extremely elongate, cylindrical bodies and legs that closely resemble twigs, stems, or bark, providing highly effective crypsis against visually hunting predators. The order includes approximately 3,000 described species, ranging from small, slender forms to the world's longest insects (exceeding 600 mm in some Phryganistria and Phobaeticus species). Many species supplement camouflage with secondary defenses including startle displays, deimatic behavior, reflex bleeding, or chemical secretions. The family Phylliidae (leaf insects) represents a derived lineage with flattened, leaf-mimicking morphology.

Etymology

From English 'stick' + 'insects', referring to twig-like appearance; order name Phasmatodea from Greek phásma ('apparition, phantom'), alluding to their ghostly resemblance to vegetation.

Example

The giant stick insect Ctenomorpha gargantua from Queensland, Australia, reaches over 500 mm in body length and relies primarily on crypsis, freezing in place with forelegs extended to mimic a small branch.

Synonyms

• walkingsticks
• phasmatodeans
• phasmids
• stick bugs

Related Terms

• Phasmatodea
• Leaf insects
• Crypsis
• mimicry
• deimatic behavior
• Phylliidae
• Phobaeticus
• Phryganistria

Usage Notes

The term 'stick insects' most commonly refers to elongate, twig-mimicking species in Phasmatodea, though it is sometimes used more broadly to include leaf insects (Phylliidae). 'Walkingstick' and 'walking stick' are frequent North American variants; 'phasmid' is the preferred technical term in entomological literature. Regional common names vary widely and include potentially confusing terms like 'Devil's darning needles' (also applied to Odonata and Tipulidae).