Ironclad ID: Tool for Diagnosing Ironclad and Cylindrical Bark Beetles (Coleoptera: Zopheridae) of North America north of Mexico
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Glossary of Morphological Terms

The following structures and descriptive terms are found throughout the Ironclad ID resource. The terms below have been defined using the Torre-Bueno Glossary of Entomology (1989), Lawrence et al. (2010), and Lawrence et al. (1999).

  • Abdominal process (intercoxal process of abdominal ventrite I): projection on ventrite 1 which extends anteriorly between metacoxae.

  • Abdominal ventrite: visible ventral abdominal sclerite. Ventrite number does not correspond to true sternite number except in rare cases where sternite 1 is visible. Also called ventrite.

  • Acute: pointed; terminating in or forming less than a right angle.

  • Antennae: paired, segmental appendages, borne one on each side of head, functioning as sense organs and bearing a large number of sensilla.

  • Antennal club: an enlarged portion of the antennal apex, consisting of a variable number of antennomeres (often 3). In an incrassate, antenna the antennomeres gradually enlarge towards to apex, but if there is an abrupt change in length or width at some point, then the antennomeres beyond this are considered to be part of the club.

  • Antennal cavity: a prothoracic cavity for housing the whole antenna or a portion of the antenna (usually the club).

  • Antennal insertion: point of attachment for the antennae, consisting of an opening in the head capsule, sometimes with a reinforced sclerotized ring.

  • Antennomere: antennal segment; including scape, pedicel and flagellomeres. NOTE: the flagellum is composed of all antennal segments proceeding the scape and pedicel. Any individual antennal segment is commonly called an antennomere.

  • Anterior: in front; before.

  • Apex (pl. apices): end of any structure distad to the base.

  • Apical (apicad): an adjective (or adverb) denoting position near or movement toward the apex of a body part. The apex of the head or pronotum is at the anterior end while that of the abdomen or an elytron is at the posterior end; on the legs or antennae, apical and distal are synonymous.

  • Arcuate: arched or bowlike.

  • Basal (basad): an adjective (or adverb) denoting position near or movement toward the base of a body part. The base of the head or pronotum is at the posterior end while that of the abdomen or an elytron is at the anterior end; on the legs or antennae, basal and proximal are synonymous.

  • Bisinuate: with 2 sinuations or incisions.

  • Callosity: a rather flattened elevation not necessarily harder than the surrounding tissue.

  • Canthus (pl. canthi): a sclerotized bar encroaching on the eye.

  • Carina (pl. carinae): an elevated ridge or keel, not necessarily high or acute.

  • Clypeus: the area of the beetle head between the frontoclypeal suture and the labrum, or in the absence of a frontoclypeal suture, the area just behind the labrum and in front of the eyes. Also called the epistoma.

  • Concave: hollowed out; the interior of a sphere as opposed to the outer or convex surface.

  • Confluent: running together.

  • Connate: united at base, or along the entire length; fused.

  • Connate ventrites: ventrites which are immovably united, so that they can not slide over one another as they can when joined by membrane. This may be used as a synonym with fused ventrites, but they are always deparated by a groove or line, while fusion sometimes involves the disappearance of any joining line.

  • Convex: the outer curved surface of a segment of a sphere, as opposed to concave.

  • Cordate (cordiform): heart-shaped; triangular, with the corners of the base rounded; not necessarily emarginate at the middle of the base.

  • Coxa: the basal segment of the leg, by means of which it is articulated to the body.

  • Denticulate: set with little teeth or notches.

  • Depressed: flattened down as if pressed.

  • Distal (distad): an adjective (or adverb) denoting position near or at or movement toward the free end of an appendage or that furthest from the body.

  • Dorsal (dorsad): an adjective (or adverb) denoting position near or movement toward the upper side of the body or a body part.

  • Elytral carinae: carinae found on the elytral disc (dorsal surface), not including the lateral carinae that separate the disc from the epipleura.

  • Elytral declivity: the downward slope of the elytra, near the apex.

  • Elytral suture: the line formed when two elytra in folded or closed position meet along the midline.

  • Elytron (pl. elytra): the fore wing in Coleoptera, which is more or less uniformly sclerotized and in resting position is longitudinally oriented, usually meeting the opposite elytron along the midline.

  • Emarginate: notched at the margin.

  • Epipleuron (pl. epipleura): a lateral, infolded portion of the elytra, which is separated from the elytral disc by a distinct fold or carina and which usually fits against the lateral portions of the abdomen.

  • Epipleural fold: a fold in the elytron which separates the elytral disc from the epipleuron.

  • Explanate: spread out and flattened; applied to a margin.

  • Eye facet: individual parts of the external surface of the compound eye; often convex but sometimes more or less flattened.

  • Femur (pl. femora): the third and usually the stoutest segment of the beetle leg, articulated proximally with trochanter (or if the latter is absent, then the coxa) and distally with the tibia.

  • Ferrogino-testaceous: rusty yellow-brown.

  • Ferrugineous: rusty red-brown.

  • Frons: the area between the eyes and just behind the frontoclypeal suture. In Coleoptera it is not or only rarely separated from the vertex posteriorly.

  • Heteromeroid (trochanter type): a type of strongly oblique trochantofemoral attachment with the base of the femur abutting the coxa.

  • Hypomeron (pl. hypomera): that portion of the pronotum which is visible from the ventral side; when there is a lateral pronotal carina, this is the portion below that carina (the pronotal disc being above it).

  • Labial palp: the one- to four-segmented appendage of the insect labium, borne on the palpiger.

  • Lateral (laterad): an adjective (or adverb) denoting position near or movement toward the sides of the body.

  • Lateral pronotal carina (pl. carinae): a sharp lateral edge on the prothorax separating the pronotal disc above and the hypomeron below.

  • Macula (pl. maculae): a spot or mark.

  • Maculate: spotted; with many superficial marks or spots.

  • Mandible: one of the paired lateral biting jaws in beetles, lying just below the labrum and just above the maxillae. The mandible is usually relatively stout and heavily sclerotized, with one or more apical teeth, a basal mola or grinding area, a membranous prostheca distal to the mola and sometimes one or more accessory teeth.

  • Matte: lacking or deprived of luster or gloss.

  • Maxillary palp: one- to seven-segmented appendage of the insect maxilla, carried by the stipes on its outer end, being sensory in function.

  • Medial fleck (of flight wings): binding patch located in the medial field. In Polyphaga this is located in front of MP3+4.

  • Median: on the midline.

  • Mesal (mesad): an adjective (or adverb) denoting position near or movement toward the midline of the body.

  • Meso-: prefix referring to a structure forming part of the mesothorax, including mid legs (e.g. mesocoxa, mesepisternum, mesotarsus, mesepisternum).

  • Mesocoxae: the coxae of the mesothorax.

  • Mesothorax: the second (middle) segment of the beetle thorax.

  • Mesotibia: the tibia of the mesoleg.

  • Meta-: prefix referring to a structure forming part of the metathorax, including hind legs (e.g. metacoxa, metepimeron, metatibia, metaventrite).

  • Metacoxae: the coxae of the metathorax.

  • Metathorax: the third (posterior) segment of the beetle thorax.

  • Metaventrite: ventral plate lying behind and between the mesocoxal cavities and delimited laterally by the metanepisterna.

  • Nodule: a small knot or swelling.

  • Oblique: slanting; any direction between perpendicular and horizontal.

  • Opaque: without any surface luster.

  • Palpomere: palp segment.

  • Pedicel: the second segment of the insect antenna, supporting the flagellum.

  • Piceus: black.

  • Postcoxal process: mesal extension of the posterior part of the propleuron or hypomeron behind the procoxa, which may meet the prosternal process or the opposing postcoxsal process, thus closing the procoxal cavitiy externally.

  • Posteriad: toward the posterior end.

  • Posterior: hinder or hindmost, opposed to anterior; hind or rear.

  • Preapical groove (of abdominal ventrite V): a groove located just before the apex of abdominal ventrite V.

  • Pro-: prefix referring to a structure forming part of the prothorax, including fore legs (e.g. procoxa, prosternum, protrochantin, protarsus).

  • Procoxae: the coxae of the prothorax.

  • Procoxal cavities: countersunk prothoracic housing into which the procoxa fits. Formed in part by the prosternum and in part by the propleuron or pronotal hypomeron.

  • Procoxal cavities: external closure: Externally closed when the postcoxal processes of the hypomera meet the prosternal process or meet one another.

  • Pronotal disc: the area of the pronotum which is visible dorsally and usually delimited laterally by the two lateral carinae. Contrasted with the paired pronotal hypomera, which extend onto the ventral surface.

  • Pronotum: dorsal portion of the pronotum, lying above the lateral pronotal carinae when these are present.

  • Prosternal process: Posterior projection of the mesal portion of the prosternum which extends between the procoxae and may overlap the mesoventrite or fit into the mesoventral cavity.

  • Prosternum: used for the entire ventral plate lying in front of and between the procoxae and between the notosternal or pleurosternal sutures.

  • Prothorax: the first segment of the beetle thorax.

  • Protrochantin: a precoxal sclerite articulating with the procoxa, prosternum and pleuron or sometimes fused to the pleuron or apparently absent.

  • Proximal: that part of an appendage nearest the body, as opposed to distal.

  • Pubescence: short, fine, soft, erect hair or down.

  • Pubescent: downy; clothed with soft, short, fine, loosely set hair.

  • Puncture: a small impression on the cuticle, like that made by a needle.

  • Scabrous: irregularly and roughly rugose; possessing short, sharp projections or wrinkles.

  • Scape: the first or basal segment of the insect antenna.

  • Scutellar Shield: exposed portion of the mesoscutellum which lies between the bases of the elytra.

  • Scutellary striole: a shortened stria or puncture row lying just laterad of the scutellum but not extending very far posteriorly.

  • Scutellum: posterior portion of mesotergum. Often referring only to that portion of the scutellum which is visible between the bases of the elytra (see Scutellar Shield).

  • Secretory pore: a pore that exudes a glandular secretion.

  • Serrate: sawlike, i.e., with notched edges like the teeth of a saw.

  • Serrulate: finely serrated; with minute teeth or notches.

  • Seta (pl. setae): a sclerotized, hairlike (or scalelike) projection of cuticula arising from a single trichogen cell and surrounded at the base by a small cuticular ring.

  • Sinuate: wavy, applying specifically to edges and margins.

  • Spine: a multicellular, more or less thornlike process or outgrowth of the cuticle not separated from it by a joint.

  • Subantennal groove: groove or concavity lying below the antennal insertion and housing the base of the antenna. Placed between the eye (if present) and the mandibular articulation, and sometimes extends below or behind the eye.

  • Subequal: similar, but not equal in size, form or length.

  • Subgenal ridges: a pair of sharp longitudinal ridges extending from the maxillary articulations to the posterior region of the head and usually forming the lateral edges of a concavity. The subgenal ridges usually occur in conjunction with a strongly declined head and fit against the procoxae when the head is at rest.

  • Sublateral: just inside the lateral margin.

  • Sublateral pronotal carina: applied to various longitudinal carinae lying mesad of the lateral carinae. These may extend the length of the pronotal disc or be restricted to the posterior angles.

  • Tarsal claw: usually one of two articulated, sclerotized, claw-like processes attached to the apex of the tarsus. These claws and the empodium comprise the pretarsus. Occasionally, there is a single claw or none at all.

  • Tarsal formula: the number of tarsomeres on the fore, mid, and hind tarsi, respectively.

  • Tarsomere: one of the divisions of the tarsus.

  • Tarsus (pl. tarsi): the fifth segment of the beetle leg, which is articulated proximally with the tibia and distally with the pretarsus; almost always subdivided into two to five tarsomeres.

  • Temple: the lateral portion of the head between the posterior edge of the eye and an abrupt narrowing of the head to form a posterior neck.

  • Testaceous: brownish-yellow.

  • Tibia (pl. tibiae): the fourth and often the longest segment of the beetle leg, articulated proximally with the femur and distally with the first tarsomere.

  • Tibial spur: an articulated, multicellular, spur-like process located at the apex of the tibia; usually paired but occasionally single, and sometimes absent.

  • Tomentose: covered with a form of pubescence composed of short, matted, woolly hair.

  • Trochanter: the second segment of the beetle leg, articulated proximally with the coxa and distally with the femur; usually a relatively small sclerite and occasionally highly reduced or absent.

  • Trochantin: a precoxal sclerite articulating with the coxa, sternum and pleuron or sometimes fused to the pleuron or apparently absent.

  • Truncate: cut off squarely at the tip.

  • Tubercle: a small knoblike or rounded protuberance.

  • Variegated: of several colors in indefinite pattern.

  • Ventral (ventrad): an adjective (or adverb) denoting position near or movement toward the lower side of the body or a body part.

  • Vestiture: the general surface covering comprised of cuticular projections, e.g., setae, scales, or spicules.

  • Wing (hind wing): wings arising from the metathorax. NOTE: In many Zopherinae, the hind wings are completely absent.


Colydium lineola
Colydium lineola
© Ken Karns

© 2011-2015 Lord, N.P., Nearns, E.H., and K.B. Miller