Phasmatodea

Definition

An order of hemimetabolous insects comprising the stick insects, leaf insects, and walkingsticks, characterized by extreme cryptic morphology that mimics twigs, bark, or foliage; body plan typically elongate and cylindrical or dorsoventrally flattened, with slender legs often held close to the body; many species wingless, but when present, forewings are leathery tegmina and hindwings membranous and fold fan-like beneath. Defensive adaptations include startle displays with brightly colored hindwings, reflex bleeding, spines, and in some taxa, chemical secretions that can irritate vertebrate predators.

Etymology

From Greek phasma (apparition, phantom) + -odea (resembling), alluding to their ghostlike resemblance to plant material.

Example

The giant spiny stick insect Extatosoma tiaratum (family Phasmatidae) is a widely kept phasmatodean that combines thorn-like body projections with a death-feigning defense.

Synonyms

• Phasmida
• Phasmatoptera

Related Terms

• Phylliidae
• Phasmatidae
• Timematodea
• Verophasmatodea
• Crypsis
• tegmen
• hemimetabolous
• mimicry
• defensive secretion

Usage Notes

Phasmatodea is the prevailing ordinal name in recent literature, though Phasmida (ending in -ida, consistent with most insect orders) is still widely used, particularly in European taxonomy. The group was historically treated as Phasmatoptera within Orthopteroidea. Subordinal classification recognizes Timematodea (basal, relictual) and Euphasmatodea (containing the vast majority of extant diversity, sometimes split into Verophasmatodea and others). Leaf insects (family Phylliidae) are nested within Phasmatodea, not a separate order.