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Cecilia Rogers, Bayless, Victoria M., Hudnall, Chance D., Ashbrook, Aaron
Download Publication ID: 4073
Cockroaches are common household pests and members of the taxonomic order Blattodea. Most cockroach species are important recyclers or decomposers of decaying matter, but some can also be mechanical disease vectors of enteric viruses, bacteria and nematodes, in addition to contaminating indoor surfaces, and depositing allergens. Cockroaches are hemimetabolous insects, meaning they undergo incomplete metamorphosis and lack a pupal stage. Immature cockroaches, or nymphs, lack wings and are unable to reproduce, but otherwise look somewhat similar to adults in appearance. Some physical characteristics that distinguish cockroaches from other insects include a shield-like pronotum (part of the thorax) that covers part of the cockroach’s head, leathery wing coverings, an ovular body shape, a pair of cerci (paired sensory appendages) on the tip of the abdomen and filiform, or threadlike antennae.
Distinguishing male and female cockroaches is relatively straightforward. Male cockroaches possess a pair of anal styli that look like a smaller set of cerci. Females tend to be slightly larger than males and wider-bodied, in addition to other slight differences that vary by species. Females may also carry an ootheca or egg case until they attach it to a surface or drop it, depending on species. The descriptions here will assist in differentiating common cockroach species to improve management strategies. Preferred environments also vary by cockroach species.
Anal cerci: A pair of appendages found on the end of the abdomen.
Anal styli: A pair of appendages only found on males.
Antennae: Sensory organs; look like beaded strings on cockroaches (filiform).
Labial palp: The smaller set of palps.
Labium: The “lower lip.”
Labrum: The “upper lip.”
Maxillary palp: The larger set of palps.
Mesothoracic leg: Midlegs stemming from the mesothorax.
Mesothorax: The second thoracic segment.
Metathoracic leg: Hindlegs stemming from the metathorax.
Metathorax: The third thoracic segment.
Ovipositor valve: Where egg cases are carried before deposition.
Palps: Fingerlike sensory appendages, feelers that are covered in sensory “hairs” used for tasting.
Pronotum: The top portion of the prothorax; modified in cockroaches to cover part of the head.
Prothoracic legs: Forelegs stemming from the prothorax.
Prothorax: The first segment of the thorax.
Tegmina: Modified forewings that are tough and leathery to protect the more delicate hindwings; they attach to the mesothorax.
A simple diagram of basic adult cockroach anatomy. Definitions can be found in the accompanying anatomy key. Illustration by Cecilia Rogers
Cecilia Rogers, Transient–Research, Entomology Department
Chance D. Hudnall, Graduate Assistant, Entomology Department
Aaron R. Ashbrook, Assistant Professor, Entomology Department
Victoria Bayless, Research Associate, Entomology Department
For article with additional data, please see PDF.
P4073_ID_Cockroaches_LA_SL101326pdf / 3.30MB