Blattodea

Definition

An order of insects (class Insecta) comprising cockroaches and termites, characterized by leathery forewings (tegmina), chewing mouthparts, and incomplete metamorphosis. Formerly, termites were classified separately as order Isoptera, but molecular phylogenetics has demonstrated their origin from within the cockroach lineage, making them eusocial cockroaches cladistically. The order contains approximately 4,400–7,500 described species across roughly 20 families, with most diversity concentrated in tropical and subtropical regions. While fewer than 30 species are domestic pests, the vast majority occupy critical ecological roles as decomposers, detritivores, and soil engineers.

Etymology

From Latin blatta (cockroach, moth) + New Latin -odea (order suffix), coined by Pierre André Latreille in 1810.

Example

The American cockroach (Periplaneta americana) and the eastern subterranean termite (Reticulitermes flavipes) both belong to Blattodea, despite their dramatically different social structures and ecological roles.

Synonyms

• Dictyoptera (superorder, obsolete usage)

Related Terms

• Dictyoptera
• Isoptera
• Mantodea
• Polyneoptera
• Neoptera
• tegmina
• Ootheca
• eusociality
• cryptocercid
• symbiotic flagellates

Usage Notes

The taxonomic scope of Blattodea expanded significantly following molecular studies in the early 2000s that demonstrated termites (formerly Isoptera) nest within the cockroach radiation. Some specialists now treat termites as family Termitidae or as multiple families within Blattodea, while others retain 'Isoptera' informally for the termite clade. The seven-family system mentioned in older literature (Blattidae, Blaberidae, etc.) has been superseded by phylogenetic revisions recognizing additional families including Corydiidae and Nocticolidae. When discussing 'cockroaches' without qualification, authors may intend the paraphyletic group excluding termites, or the entire order—context determines meaning.