Glossary of Weevil Characters

There is much disagreement in different publications as to the correct name to use for different characters and, indeed, just what those characters are. Miguel Alonso-Zarazaga raised this issue in the Forum; in fact it was one of the drivers to set up the site in the first place. The preliminary glossary below is a start at addressing these problems.

The intent is to enable users to discover the meaning of terms found in descriptions, and to select the appropriate term to use.  Terms in wider use are not included, and the user is directed to more general publications such as Torre-Bueno's Glossary of Entomology. This list cannot be more than indicative, but many of the characters are discussed more fully in other publications, and included in larger dictionaries.  See, for example, Davis (2009), Lyal (1995), Maggenti et al, (2008), Morimoto & Kojima (2003), Thompson (1992), Torre-Bueno (1989), Wanat (2001).

If you add references to the bibliography please could you include the key word 'morphology' to help others find them?

If citing this Glossary, an appropriate citation is Lyal, C.H.C. (Ed.) Glossary of Weevil Characters. Weevil Workers Website. https://www.curculionoidea.org/glossary (accessed xx/xx/xxxx).

Please comment and add to the contents, which will be revised regularly.

Chris Lyal

Accessory glands (female genitalia) – glands associated with the female genitalia, which in at least some cases contain symbiotic organisms. Probably not homologous throughout Curculionoidea, and appear in different forms and attached to different parts of the genitalia.  See Kuschel (1987).

Adelognatha (informal group of weevils) - a group of Curculionidae characterised by the adelognathous character state (q.v.), broadly equivalent to the Entiminae sensu Thompson (1992). They are thus also characterised by a short, broad rostrum, the presence of a deciduous mandibular process, larval antennae lacking a projecting apical part; larvae living free in soil. Some Entiminae have phanerognathous mouthparts, however (q.v.). The group has no formal status, and is not monophyletic.  See also ‘Phanerognatha’.

Adelognathous (head, mouthparts) – refers to the maxillae being concealed by the prementum.  Thompson (1992) notes that in some cases the stipites are visible at the posterior angles of the prementum, and that in fact the degree to which the maxillae are concealed by the prementum is very variable. The contrasting term is ‘Phanerognathous’ (q.v.)

Adelphic – female mating with more than one male – not limited to weevils.

Aedeagal apodemes (male genitalia) – see Penis apodemes

Aedeagus (male genitalia) – Combined structure comprising the tegmen and penis. See also 'pedal' and 'pedotectal' as types of aedeagus.

Aggonoporium (male genitalia) – Term coined by Arzanov (2003) for sclerite or complex of sclerites in the endophallus around the junction with the ductus ejaculatorius. The sclerites may participate in attaching the endophallus to the bursa copulatrix during copulation. See Transfer apparatus.

Airtube (larva) – respiratory appendage (May, 1994)

Annulated – segmented; in rings – sometimes used of antennal club.

Anapleural suture (metathorax) – see metanepisternal suture (preferred term).

Anepisternum (thorax) - anterior sclerite of the peluron, discernable on the mesothorax and metathorax in weevils (mesanepisternum, metanepisternum). Synonym: episternum. (definition changed May 2012)

Anophthalmic (head) – lacking eyes.

Antenna (head) - sensory appendage on either side of the rostrum, comprising 11 articles: scape, 7-segmented funicle and 3-segmented club) (see under ‘Antennal segment’ for discussion of terminology of the antennal ‘segments’). Although sometimes referred to as 12-segmented, this depends on the interpretation of the club components (q.v.) and is apparently a misapprehension. (see states: geniculate antenna, subgeniculate antenna) See also Antennal segment, desmomere, antennomere. (definition changed 01/06/2012)

Antennal article (head) – see Antennal segment (preferred term). (definition changed 23/11/2011)

Antennal club (head) - see under Club.

Antennal insertion (head) – point of attachment of the antenna.  Antennal insertions are considered to be exposed when at least some portion of each antennal socket is visible from above the long axis of the rostrum. (After Lawrence, Beutel, Leschen & Slipinski, 2010).

Antennal segment (head, antenna) – individual elements of the antenna.  The terms used suffer from a difference in meaning between morphological correctness and in practice. Morphologically the antenna, like other insect antennae, comprises three true ‘segments’: a scape, pedicel and flagellum. The flagellum may be secondarily subdivided into a number of antennomeres, which are not true segments (in terms of holding muscle insertions). However, the traditional division in weevils is into scape, funicle and club, the funicle comprising the pedicel and up to 6 antennomeres of the flagellum (rarely seven if an antennomere more usually part of the club is separate), and the club a further three flagellum antennomeres. The pedicel is sometimes referred to as the first antennomere or first segment of the funicle. The terms pedicel and flagellum are not used in weevil taxonomy. This provides confusion over terminology, with the different articles being termed segments, antennomeres, desmomeres, joints etc.  The elements of the club are rarely termed antennomeres but the term ‘clubomere’ has been used (not recommended here).  The term ‘segment’ is adopted here for all articles, recognizing the morphological inappropriateness of this. Synonyms: antennal article, antennomere, desmomere (in part), clubomere (in part), joint. (definition changed 1 June 2012).

Antennomere (head, antenna) – see Antennal segment (preferred term).The issues surrounding the use of this and other terms for the structure are discussed under ‘Antennal segment’ above. (definition changed 1 June  2012).

Anterior tentorial pit (head) – the invagination of the head capsule corresponding to the position of the anterior arms of the tentorium inside the head.  The Anterior Tentorial Pits lie at the anterior end of the subgenal sulcus in weevils, near the mandibular articulation (Lyal, 1995)

Apical membranous lobe (male genitalia) – unsclerotised posteriorly-directed extensions of parameroid lobes on tegmen (Wanat, 2007).

Apical setal comb (leg, tibia) – row of strong setae around the apex of the tibia and projecting distad. There is often a gap dorsally between the comb on the posterior and anterior faces, to allow the tarsus to be reflexed. The anterior comb may extend along the dorsal face of the tibia (e.g. some Molytinae), in which case it is termed 'ascending'.  (Thompson, 1992).  See also ‘secondary comb’, ‘corbel’. Synonyms: distal comb, tibial comb, setose fringe, fringing setae.

Apodeme - chitinous ingrown of the exoskeleton to which muscles are attached; rod-like projection from any of several structures (e.g. penis, tegmen).

Apodemes of penis (male genitalia) – see Penis apodemes.

Apodeme of tegmen (male genitalia) – See Tegminal apodeme

Appendiculate claw (leg, tarsus) - See Tarsal Claw.

Appressed (of scales) - scales in contact with the cuticle over all or most of their area.

Apterous – lacking wings

Baculum (pl – baculi) (female genitalia) – Sclerotised bars or struts which serve to support a membranous ovipositor.

Basal arms (of spiculum gastrale) (male genitalia) – the posterior fork of the spiculum gastrale, on which various muscles attach.  Synonym; furcal arms.

Basal piece (male genitalia) – see Tegminal ring (sometimes also tegminal apodeme).

Basal pocket (elytra, submarginal fold) - the region of the sublarginal fold that diverges away from the outer wall of the elytra to form a more or less deep pocket to accommodate the pleurite of the basal ventrites and the metathoracic lateral sclerites. See also 'Submarginal fold'.

Basal sclerites (male genitalia) – paired (usually) sclerites lying near the junction of the endophallus with the ductus ejaculatorius. Of variable form. See Transfer apparatus.

Basisternum (thorax) - the anterior part of each sternum, meeting the sternellum posteriorly.  Sometimes used incorrectly for the sternellum (q.v.) on the prothorax, but can be distinguished from this because the sternellum lies between and behind the coxae, whilst the basisternum is before the fore coxae.

Beak see rostrum (preferred term).

Bevel (leg, tibia) – see discussion under Corbel

Bifid claw (leg, tarsus) see "Tarsal Claw"

Buccal cavity (head, mouthparts) – mouth cavity

Bursa (female genitalia) – large closed membranous lobe of female genitalia arising dorsally from vagina generally at same point as common oviduct. Synonyms: bursa copulatrix; copulatory pouch; vaginal bursa. [amended May 2020]

Bursa copulatrix (female genitalia) – see Bursa

Bursal sclerite (female genitalia) – sclerite lying in the vaginal and bursal floor around the junction with the common oviduct and spermathecal duct.

Cap-piece (male genitalia) – see Parameroid plate.

Cardo (head, mouthparts) – basal piece of the maxilla

Cervical sclerites  (head) - small trapezoidal triangular sclerite or pair of sclerites at the posterior end of the gular suture(s) (Lyal, 1995). Synonym: postgula.

Claw (leg, tarsus) - see 'Tarsal claw" (preferred term).

Club  (head, antenna) - the apical antennal segments. The club generally has three segments (see under ‘Antennal segment’ for discussion of terminology of the antennal ‘segments’), either separate as in some basal groups or combined as in most Curculionoidea. In many weevils there appear to be 4 club segments, each delimited by a suture and each bearing a ring of elongate setae. However, the form of the groove between the apical 'segment' and the others differs from that between the true antennomeres (Wanat, 2001). The apparent 4-segmented club has been termed 'pseudotetramerous' by Wanat, 2001. The elements may be termed ‘club segments’, ‘club antennomeres’ or ‘antennomeres of the club’, the first of these being least clumsy (although inaccurate); the term ‘clubomere’ has also been used but is linguistically dubious. Key character states: loose: articulation between segments and segment 'neck' visible; compact: articulation and basal constrictions not seen, but borders between segments clearly visible; connate: borders or sutures between segments partly or completely lost. See Wanat (2001)  Synonym: Antennal club. (definition changed 1 June 2012)

Clubomeres (head, antennal club) – the antennomeres that make up the club of the antenna. – see Antennal segment (preferred term). (definition changed 23 November 2011)

Collar (prothorax) – anterior of prothorax when delimited, at least laterally, by a groove or simply an angle, from the rest of the prothorax to enclose the base of the head capsule; often developed into postocular lobes.

Collum (female genitalia, spermatheca) – the part of the spermatheca to which the spermathecal duct is connected (see duct lobe). [amended June 2015].

Common oviduct (female genitalia) – see median oviduct.

Complex apparatus (male genitalia, endophallus) – see transfer apparatus.

Connate - of two segments or other articulating parts of the body. Not freely moving against one another.  There may or may not be a line between them marking the original suture. [amended June 2012]

Copulatory pouch (female genitalia) – see Bursa.

Copulatory sclerites (male genitalia, endophallus) - more or less complex sclerotised elements in endophallus around the gonopore.  Velázquez de Castro et al. (2007) distinguished three different sclerites in Sitonini: pinna, cucullus, and hamulus. cf flagellum. Synonyms: aggonoporium; basal sclerite; complex apparatus; armature sclerites; anterior endophallic sclerite; sclerotized structure of internal sac, trnasfer apparatus. (preferred term changed 12 June 2020)

Corbel (leg, tibial apex) – area at apex of tibia defined by setal combs and tibial ridges. The terminology has been and continues to be confused, and relevant terms are summarised here to facilitate understanding. Thompson (1992) recommends the term ‘corbel’ be abandoned in favour of ‘outer bevel’ (q.v.) and ‘inner flange’ (q.v.), an argument based partially on Latin derivation of the term, since challenged by Oberprieler (see discussion under corbel ). Synonyms: Körbichen, corbulae, corbeille

• Apical setal comb - ring of stout setae around the tibial apex directed distad (q.v.). Anterior and posterior sides of the ring may not be joined, and ring may be incomplete.

• Bevel – a slanted area between the tibial apex and the anterior face of the tibia. An ambiguous term.

• Inner flange – Smooth flange developed anteriorly on the tibial apex shielding the tarsal insertion and sometimes extending the full width of the tibial apex.  It may be raised only near the tibial insertion or extend from dorsal to ventral margins of the tibia; it lacks setae. If the uncus is present its base is the inner flange.  It can occur on all three tibiae (Thompson, 1992). [definition changed 3 Aug 2020 - the earlier incorrect definition identified the flange as the tibial margin]

• Open corbel - apex of tibia with apical setal comb (anterior and posterior) but no secondary comb and no inner flange. The space delimited by the inner flange and the anterior aical setal comb lacks setae or scales. Synonym: simple [tibial apex]; [tibial apex] without corbel.

• Enclosed corbel: see True corbel

• False Corbel - tibial apex with inner flange raised distal to setal comb (Thompson, 1992).  Synonym: Semi-enclosed corbel.

• True corbel – more or less flat or concave area at an angle between the tibial apex and the anterior face of the (particularly hind) tibia, demarcated distally by the anterior apical setal comb and proximally by a secondary setal comb (closed or enclosed corbel) or lacking a proximal setal row.  The surface may be lacking scales or with scales.  Synonym: outer bevel.

Cornu (female genitalia, spermatheca) – the apical, generally curved, more or less acuminate part of the spermatheca.

Coxite (female genitalia) - see Gonocoxite (preferred term)

Coxite-stylus (female genitalia) - term applied to the structure where the stylus and gonocoxite are believed to have fused. Coined by Howden (1992) in discussion of eyeless weevils in the Nearctic and Neotropics. Synonym: vaginal palp.

Deciduous mandibular process (head, mandible) – horn- or blade-like processes on the mandibles of Entiminae some Brachycerinae that almost always fall off in early adult life, leaving a distinct scar. The deciduous process may sit on a pedicel, which is present after the process has fallen off.  See extended discussion in Thompson, 1992. Synonyms: pupal mandibles, mandibular appendages, mandibular cusp, deciduous pieces, false mandibles, provisional mandibles, Supplementzähne.

Declivity  (elytra) – the posterior part of the elytra that slopes ventrad.Synonym: elytral declivity.

Dense (of sclaes) - scales very close to one another or subcontiguous (see 'sparse').

Desmomere (antenna, funicle) – the pedicel and antennomeres that make up the funicle of the antenna (Alonso-Zarazaga, 1989) – see discussion under Antennal segment (preferred term). Synonyms: antennomere, funicle segments, antennal segment. (definition changed 1 June 2012)

Disc (thorax, pronotum) – dorsal portion of the pronotum.

Discrimen (thorax, metathorax) - Median longitudinal depressed line sometimes present on the metaventrite, corresponding with a median ridge internally representing the invagination of the true metasternum. The ridge is usually connected with the metendosternite. May also be visible on the mesoventrite.

Dorsal Adventitious Tooth (leg, tibia) - tooth on apex of tibia dorsally in addition to uncus.

Dorsal Apical Projection (leg, tibia) - dorsal projection on hind tibia lying at the basal end of the apical setal comb when this is ascending. 

Dorsal plate (male genitalia) – see Parameroid plate.

Duct-lobe (female genitalia, spermatheca) – the part of the spermatheca from which the spermathecal duct arises.  Sometimes extended into a lobe or a tube. Synonym: collum.

Ductus ejaculatorius (male genitalia) – ectodermal duct opening into the endophallus. Synonym: ejaculatory duct. (definition changed 3 Aug 2020)

Ejaculatory duct (male genitalia) – see Ductus ejaculatorius.

Elbowed antenna – see geniculate antenna

Elytral declivity see declivity.

Elytral file – see file.

Elytral strigil – see file.

Elytral stria (pl - Elytral striae) (elytra) – longitudinal groove or row of punctures along elytra.  There are usually 10, with striae III and VIII often joining posteriorly.  The first stria is the one closest to the sutural margin of the elytron. Synonyms: stria.

Elytral submarginal fold (Elytra) – the projecting longitudinal ridge on the ventral surface of the elytra near the costal margin.  In the basal third it may be more or less strongly curved away from the elytron inner surface, this character having been used for the Barididae of Zherikhin & Egorov (1990). The fold is likely to function in locking the elytron to the abdomen and metathorax, the fold width and depth basally being related to the size of the metepisternite. Discussed by Davis (2009). Synonyms: epipleural fold, inferolateral flange.

Elytral sutural flange (elytra) - flange on the sutural margin of each elytron ventral to the margin itself.  The flange on the right hand elytron fits in the groove between the dorsal surface of the left hand elytron and the flange below it.  The margin of the left-hand elytron is wider than that of the right-hand elytron in 'higher' weevils, but about the same in 'lower' weevils. In higher weevils the extension of the flange allows for elytral locking when closed.  In cases where the elytra are 'fused' the 'fusion' may be due to the flanges being curled around each other and thus immovable. 

Elytro-tergal stridulation system (elytra and abdomen) – the organ responsible for sound production in many higher weevils. It comprises a file – a closely-set patch of parallel ridges on the inner surface of the elytra near the apex or along the sutural margin, and a plectrum – usually a patch or row of tubercles or a single tubercle each side of the mid-line on abdominal tergite 7. The plectrum may be a ridge or pair of ridges in some taxa. In Ithyporina and some Cryptorhynchina the female has the file on tergite 7, derived from the wing-binding patch. The organization of the tubercles and the shape and position of the file can provide useful characters. (Lyal & King, 1996).

Emarginate – notched at the margin. May be used to indicate a concave (in plan) part of a margin.

Enclosed corbel (leg, tibia) – see discussion under corbel.

Endophallus (male genitalia) – membranous sac lying within penis contiguous with ductus ejaculatorius and penis. Sometimes armed with a variety of sclerites (see Transfer apparatus). Everts during copulation. Arzanov (2003) recognized and named a number of lobes of the endophallus. Synonym: internal sac.

Epifrons (head) - dorsal part of the rostrum extending from between the antennae anteriorly to the anterior margin of the eyes. The epifrons is rarely clearly distinguished from the frons anteriorly and the forehead posteriorly. See discussion under Head.

Epimeron (thorax) – posterior sclerite of the pleuron discernable on the mesothorax and metathorax in weevils (mesepimeron, metepimeron)

Epipleural bridge (prothorax) – see Hypomeral lobe (preferred term)

Epipleural fold - see elytral submarginal fold (preferred term)

Epipleuron (thorax, elytra) – the inflexed portion of the elytron laterally when the elytra are closed (Torre-Bueno, 1989).

Episternum (thorax) – see Anepisternum (preferred term)

Epistome (head, mouth) – sclerite immediately posterior to the labrum; since the labrum is lost / fused to the clypeus in most adult weevils other than Nemonychidae and Anthribidae the epistome is often used to discuss the sclerite immediately above the buccal cavity without having to decide if it is clypeus or clypeus + labrum fused. It may be fairly clearly demarcated from the dorsal part of the rostrum lying posterior to it (part of the frons) by colour and a ridge or depression (epistomal ridge and epistomal suture respectively) or a transverse row of setae.  Laterally there may be a depression (termed the paraclypeal depression by Morimoto & Kojima, 2003), which often has a small tuft of setae (termed the paraclypeal setae by Morimoto & Kojima, 2003). Synonyms: epistoma, clypeus.

Eye-flaps see postocular lobes (preferred term).

False spiculum (male genitalia) – see Spiculum relictum (preferred term)

False strut (male genitalia) – see Spiculum relictum (preferred term)

Fenestrae (male genitalia) – unsclerotised area of the parameroid plate (q.v.) bounded by sclerites (see suprafenestral sclerite and subfenestral sclerite).  Homology across Curculionoidea is unlikely. (see Wanat, 2007).

Fifth tarsomere (leg, tarsus) - the distal tarsomere, bearing the tarsal claws. Synonyms:  unguitractor, onychium.

File (elytra – elytro-tergal stridulation system) – patch of fine, parallel ridges on the internal surface of the elytra, generally near the apex, which form part of the elytro-tergal stridulation system. Synonyms: elytral file, elytral strigil, pars stridens, stridulatory rasp, stridulatory file.

First connecting membrane (male genitalia) - see Post-tegminal membrane. The First connecting membrane of Clark (1977) is the Pre-tegminal membrane.

Flagellum (male genitalia) – long tubular sclerite sometimes present within the endophallus with the gonopore at its apex.  In some cases (more rarely) the flagellum is one or a pair of rods within the ejaculatory duct but outside the endophallus.  The two structures are not homologous.  See also ‘Transfer apparatus’. See Wanat, 2007.

Forceps (male terminalia) – externally-visible processes from 8th sternite in the amycterine Phalidura (Thompson, 1992).

Frena (male genitalia, endophallus) – paired sclerites in endophallus, situated sub-basally when endophallus everted, comma-shaped or hook-shaped.  Kuschel (1995) suggested their presence is a plesiomorphic character state in Curculionoidea.  (Wanat, 2001, 2007).

Frons (head, head capsule) – The area dorsally on the head anterior to the antennal insertions and posterior to the epistoma, where visible.  The term is sometimes used for the area between the eyes, which might better be termed ‘forehead’. (Davis 2011) suggested in Sitophilus  that it extends ventrally and surrounds the scrobe. See discussion under head.  [amended June 2015]

Funicle (head, antenna) - the middle part of the antenna, lying between the scape and the club, comprising the pedicel and up to 6 'desmomeres' (antennomeres) ('pedicel' and 'flagellum' are terms rarely if ever used in weevil taxonomy).

Furcal arms (male genitalia) – see basal arms (of spiculum gastrale).

Furcasternum - see Sternellum (preferred term).

Gena (head) – the part of the head capsule on each side below the eye, bordered dorsally by the frontal suture, posteriorly by the occipital suture, ventrally by the subgenal suture. See also Head.

Geniculate antenna (head, antenna) - the state in higher weevils where the pedicel (basal segment of the funicle) inserts subapically on the scape, causing the funicle to be held at an angle to the scape. cf. subgeniculate antenna. Synonym: elbowed antenna.

Genital chamber (male genitalia) – see Genital pocket

Genital pocket (male genitalia) – membranous invagination between tergum VIII and sternum VIII and to which  the spiculum gastrale is attached. It includes both genital opening and rectum.  Wanat (2007) considers the pocket to extend from SVII, since SVIII is withdrawn dorsal to SVII at rest.  Wanat also places the anterior end of the genital pocket at the base of the apodemes of the penis.  Synonyms:  genital chamber, genital sheath of Wanat 2007. [amended June 2015]

Genital sheath (male genitalia) – see Genital pocket

Genital spiculum (female genitalia) - see Spiculum ventrale

Genital tract (female genitalia) – the vagina and bursa.

Gland-lobe (female genitalia, spermatheca) - see discussion under Spermatheca (ramus)

Gonatoceri (informal group term) – name applied to a grade of Curculionoidea with a geniculate antenna and male genitalia lacking a separate tectum (q.v.), broadly equivalent to the Curculionidae of Thompson (1992) which are characterised by this state.  See also Gonatocerous, Orthocerous, Orthoceri, Heteroceri.

Gonatocerous (antenna) – see geniculate (preferred term).  Term now also used to describe a group of weevils (see below) and as a ‘shorthand’ to describe typical character states (e.g. ‘gonatocerous genitalia’).

Gonatocerous (male genitalia) – see pedal genitalia (preferred term).  

Gonocoxite (female genitalia) – one of a pair of conical sclerites apically on ovipositor, associated with segment IX and between which the female vulva opens. See also 'coxite-stylus'. Synonyms: hemisternite, coxite. May be proximal and distal elements – see Lanteri & del Río, 2008.

Gonopore (female genitalia) – the opening of the common oviduct into the vagina.

Gonopore (male genitalia) – the opening through which the sperm are transferred to the female genitalia on eversion of the endophallus.  This may simply be the junction of the ductus ejaculatorius with the endophallus, at the tip of the flagellum, where present. Synonym: phallotreme.

Gonostylus - see Stylus.

Gula (head, head capsule) - the sclerite lying between the gular sutures, where these are separate (Lyal, 1995)

Gular cavity (head) – see mouth cavity.

Gular suture (head, head capsule – rostrum) - suture or pair of sutures extending from the posterior margin of the head capsule to the posterior tentorial pit(s). The sutures are often fused to a single suture in weevils. (Lyal, 1995)

Head (adult) – The head of the adult weevil has a more or less bulbous head capsule (q.v.) which accommodates the muscles of the mouthparts, and a variably elongate rostrum (q.v.) bearing the antennae and mouthparts and through which the tendons of the mandibles and maxillae pass. The various sclerites of the head are fused together and, particularly dorsally, sutures obscured; there are few reliable landmarks.  Dorsal structures: The Vertex is the posterior part of the head, extending from the occiput to the level of the antennal insertions.  Behind the eyes this may be called the Temple, between the eyes the Forehead, and between the anterior margins of the eyes and the level of the antennal insertions it may be called the Epifrons. Anterior to the epifrons the Frons may be separated by a groove, or the junction between the two simply be marked by some longer setae, at least laterally; the frons itself may lack setae or scales. Anterior to the frons the Epistome may be slightly lower or at a different angle to the frons, and may be fringed by a sparse row of setae posteriorly. The epistome and frons may be united as a distinct Nasal plate (=nasal plaque, plaga).

Head: Lateral and Ventral structures: The ventral structures were discussed extensively by (Lyal 1995). See also Gena, Gula, Gular suture, Cervical sclerites, Hypostoma, Interocular pit, Submentum, Venter

Head capsule (head, adult) – the head apart from the rostrum.  See more detailed discussion under Head.

Hemisternites (female genitalia) – see Gonocoxite (preferred term).

Hemisternite (male terminalia) – one of a pair of sclerites on sternum VIII.

Heteroceri (informal group term) – name applied to a grade of Curculionoidea characterised by possession of geniculate antennae (q.v.) and orthocerous genitalia (q.v.).  Comprises Dryophthoridae, Erirhinidae, Nanophyidae, Brachyceridae.  See also Gonatoceri, Orthoceri.

Horn sheath  (prothorax) – simple or bifurcate tube-like invagination between prothroacic horns of some Baridinae and Conderinae (Davis, 2009). Synonym: sheath.

Humeral angle – see humerus.

Humeral callus (mesothorax, elytra) – projection on humerus; may be used as simply another term for humerus, q.v. Synonyms: humeral angle, humeral umbone (for a knob-like projection).

Humerus (mesothorax, elytra) – anterolateral angle of elytron, sometimes produced into a rounded or even angulate projecting 'humeral callus' q.v.. Tends not to be produced in apterous species, where instead there is a simple curve from the base of the elytron to the widest point.  [definition changed 3 Aug 2020]

Hypomeral lobe (prothorax) - the sclerotised area behind the procoxae formed from pleural (hypomeral) projections, meeting in the midline and abutting anteriorly medially on the sternellum. Synonyms: pleural process; post-coxal bridge; post-coxal process; epipleural bridge; hypomeron.

Hypomeron - see Hypomeral lobe (preferred term).

Hypostoma (head) – ventral part of the head bearing the posterior articulation of the mandible (postcoila).  In most weevils (not Scolytinae, Platypodinae) the hypostoma projects anteriad as a hypostomal process (q.v.)

Hypostomal process (head) – Anteriad process of the hypostoma bearing the lower (posterior) mandible articulation and thus projecting below the mandible and partially enclosing the pleurostomal sinus (q.v.).  Synonyms: hypostomal tooth, postgenal arm.

Hypostomal sinus (head) – The notch between the hypostoma (q.v.) and the labium, in which the maxillae can be seen.  (Morimoto & Kojima, 2003). [amended June 2015]

Hypostomal sulcus (head, rostrum) – part of subgenal sulcus posterior to the posterior mandibular articulation.

Hypostomal tooth – see hypostomal process.

Imbricate (of scales) - scales that overlap (see also tessellate).

Inferolateral flange (elytra) - see elytral submarginal fold (preferred term).

Inner flange (leg, tibia) – a smooth flange developed anteriorly on the tibial apex shielding the tarsal insertion and sometimes extending the full width of the tibial apex. It may be raised only near the tibial insertion or extend from dorsal to ventral margins of the tibia; it lacks setae. If the uncus id present it is based on the flange. It can occur on all three tibiae. (Thompson, 1992).  See discussion on the Corbel. [amended August 2020 from the previous interpretation of the flange as the tibial margin]

Integument - exoskeleton, particularly outer covering of entire insect.

Intercoxal process (abdomen) – portion of ventrite 1 extending anteriad between hind coxae.

Intercoxal process (prothorax) – posterior extension of prothoracic sternum (basisternum) between fore coxae, meeting the sternellum if coxae sufficiently separated.

Interocular pit (head) – abrupt depression on dorsum of head, generally between eyes but sometimes more distally placed on the rostrum. This marks the junction of the dorsal tentorial arms with the head capsule (Davis 2011).

Internal sac (male genitalia) – see endophallus (preferred term).

Interstice see Interstria (preferred term).

Interstria (elytra) – raised longitudinal strip on elytra between striae. The interstria nearest the sutural margin is interstria I (Lawrence & Britton, 1991). Some authors (e.g. Vanin & Reichardt, 1976) numbered the interstriae in a different way, for example the first being called the sutural interval, the second as interstice I, the third as interstice II, and so on (Vanin, 2008). Synonyms: interval, interstice.

Interval see Interstria (preferred term)

Introse - with teeth on the apical margin of the mandible and the mandibles not opening beyond the lateral margins of the rostrum.

Joints of funicle see antennal segment.

Labium (head, mouthparts) – plesiomorphically in Coeloptera the labium comprises a tripartite prementum (bearing the labial palps), mentum and submentum.  Curculionoidea have a prementum but the mentum and submentum are not visible as separate sclerites. The single sclerite may be known as the Postmentum (e.g. Morimoto and Kojima 2003) or the submentum (e.g. Lyal, 1955).  Davis (2011) refers to the projecting portion of this sclerite supporting the prementum as the postmentum and the region between this and the posterior tentorial pits as the submentum; earlier authors termed this projecting part the peduncle.   

Labral rods (larva, mouthparts)  see tormae (preferred term).

Lateral lobes (male genitalia) – see parameroid lobes.

Latero-ventral sulci (head, rostrum) - (Wanat, 2001).

Lenticular – lens-shaped.

Ligula (head, mouthparts) –lobe of the labium, projecting anteriad of the mentum.  Plesiomorphically this comprises the glossae and paraglossae, although as Crowson (1981) states these are absent in beetles the homology of the structure is unknown. [amended June 2015]

Ligula (male genitalia) – linear sclerite dorsally on endophallus near ostium (Arzanov, 2003) [amended 12 June 2020]

Loose (of scales) - scales that are raised from the cuticle

Mandibles (head, mouthparts) - In various forms across the suborder. Terms used may include: Extrose - with teeth on the external face, the mandibles rotating away from the midline and opening away from the midline of the rostrum and not meeting apically. Introse: Teeth on the anterior/interior face, meeting when mandibles closed (the more common situation). Plurisetose: numerous setae, often of similar length on the outside face of the mandible. Paucisetose: only a few setae present on the mandible. [amended June 2015]

Mandibular cusp (head, mouthparts) – see Deciduous mandibular process.

Mandibular scar (head, mouthparts) – circular or oval scar left on mandible after loss of the deciduous mandibular process (q.v.).

Manubrium (male genitalia) – See Tegminal apodeme.

Median lobe – see Penis (peferred term).

Median Lobe Apodemes (male genitalia) – see Penis Apodemes (preferred term).

Median notch (male genitalia) – term applied to gap between parameroid lobes (Wanat, 2007)

Median oviduct (female genitalia) – the ectodermal oviduct opening into the bursa-vagina complex, often near the spermathecal duct. Synonym: common oviduct.

Median struts (male genitalia) - see Penis Apodemes  (preferred term).

Mentum (head) – middle plate of the labium, not visible as a separate plate in adult Curculionoidea.

Mesanepisternum (thorax, mesothorax) – anterior pleural sclerite of the mesothorax. Synonym: Mesepisternum. (definition changed June 2012).

Mesendosternite (thorax) - A pair of internal apodemes formed by invaginations within the mesocoxal cavities, probably homologous with the furca.

Mesepimeron (thorax, mesothorax) - Posterior pleural sclerite of the mesothorax.

Mesepisternum (thorax, mesothorax) – see Mesanepisternum (preferred term).

Mesonotum (thorax, mesothorax) – the dorsal sclerite of the mesothorax.

Mesorostrum (head, rostrum) - the section of the rostrum widened above the antennal insertion. If the broadening is absent, the term refers to the level of the antennal insertion (Wanat, 2001). Purely a descriptive term lacking any mophological significance.

Mesosternal canal see Mesoventral canal.

Mesoventral canal (mesothorax) – channel on the mesosternum to receive the rostrum when the head is rotated down and the rostrum lies along the ventral surface of the thorax. Found in some groups currently within the Cryptorhynchinae and Molytinae. (cf mesoventral receptacle). Synonyms: mesosternal channel; mesosternal canal. [amended June 2015]

Mesosternal channel see Mesoventral canal.

Mesosternal cup see Mesoventral receptacle.

Mesosternum see mesoventrite.

Mesothoracic receptacle see Mesoventral receptacle.

Mesoventral receptacle (thorax, Mesoventrite) – cup-shaped depression of the mesothorax that accepts the tip of the rostrum if this is bent between the front legs. It may be in the form of a full cup with lateral walls and a posterior wall, or with lateral walls only. Not homologous across Curculionoidea, although often used as an apomorphy for Cryptorhynchinae. Synonyms: mesosternal cup; mesothoracic cup; mesothoracic receptacle; pectoral receptacle. [amended June 2015]

Mesoventrite (thorax, mesothorax) - ventral sclerite lying in front of and between mesocoxal cavities, comprised of the fused preepisternum and basisternum (according to Wanat, 2001) or preepisterna and katepisterna (according to Lawrence et al, 2010). Generally referred to as the mesosternum in weevil taxonomic literature but the true mesosternum is invaginated. Synonym: Mesosternum.

Metanepisternal suture (metathorax) - suture between metaventrite and metepisternum. In cross-section metaventral part of suture is cup-shaped, holding the metepisternum and allowing it to flex during flight. In some higher weevils sclerolepidia are present along the suture, arising from the metaventrite. The suture may be lost in flightless weevils. (Lyal et al., 2006). Synonyms: anapleural suture, metepisternal suture, metathoracic pleurosternal suture. (term changed March 2012).

Metanepisternum (metathorax) – anterior pleural sclerite of the metathorax, lying laterad to the metaventrite and mesoventrad to the metepimeron. Often partially and sometimes completely hidden by elytra.  Synonym: metepisternum. [amended June 2015].

Metanotum (thorax, metathorax) – the dorsal sclerite of the metathorax.

Metarostrum (head, rostrum) - basal part of rostrum, from base to widening above antennal insertion (Wanat, 2001). Purely a descriptive term lacking any mophological significance.

Metasternal canal (metathorax) - see Metaventral canal

Metasternum see metaventrite.

Metathoracic pleurosternal suture see metanepisternal suture.

Metaventral canal (metathorax) - channel on the metasternum to receive the rostrum when the head is rotated down and the rostrum lies along the ventral surface of the thorax. Found in Aedemonini and Sophrorhinini. Synonym: metasternal canal. [amended June 2015]

Metaventrite  (thorax) - ventral sclerite lying behind and between mesocoxal cavities, comprised of the fused preepisterna and katepisterna (Lawrence et al, 2010). Generally referred to as the mesosternum in weevil literature but the true mesosternum is invaginated along the midline (see Discrimen). Synonym: metasternum.

Metendosternite (metathorax) – internal sclerite of the metathorax. It usually consists of a median stalk, two short to long lateral ‘furcal arms’ and a ‘longitudinal flange’ anterior to and between the arms from which a pair of tendons arise. There are often phylogenetically-important characters associated with this.

Metepimeron (thorax) – Posterior pleural sclerite of the metathorax, positioned laterad of and above the metanepisternum and mostly or completely concealed by the elytra. It may be fused to the metanpisternum.

Metepisternal suture see Metanepisternal suture (preferred term).

Metepisternum see Metanepisternum (preferred term)

Mouth cavity (head) – opening at the front of the head accommodating the mandibles, maxilla and labium. Synonyms: Buccal cavity, gular cavity.

Mucro (pl - mucrones) (leg, tibia) – tooth-like process on the inner (ventral) apical angle of the tibia, but not linked to the inner flange (q.v.). Proposed by Thompson (1992) to be homologous with the uncus (q.v.) following fusion with the inner flange.  See also ‘pre-mucro’. In many Apionidae and Nanophyidae it is present in males but not females. (amended December 2012)

Mycangium (pl - mycangia) – structures on the body used for the transport of symbiotic fungi. Found in a number of weevils, particularly Scolytinae, and have clearly evolved more than once.

Nasal plaque – see Nasal plate.

Nasal plate (head) – plate formed from the fused frons and epistome, where demarcated. See discussion under head. Synonyms: nasal plaque, plaga.

Nodulus (female genitalia, spermatheca) – the basal part of the spermatheca, between the cornu, ramus and collum. [amended June 2015]

Noto-sternal suture (prothorax) – suture, often obscured, between the notal and sternal components of the prothorax, extending anteriorly from the fore coxae externally.  Synonym: pleuro-sternal suture.

Ocular lobe (prothorax) – see postocular lobe (preferred term).

Onychium – see fifth tarsomere

Open corbel (leg, tibia) – see discussion under Corbel

Orthoceri (informal group term) – name applied to a grade of Curculionoidea with Orthocerous antennae (q.v.) and male genitalia of the plesiomorphic ‘orthocerous’ type (q.v.). These are the basal weevils on the generally-accepted cladograms. See also Heteroceri, Gonatoceri.

Orthocerous (antenna) – straight, lacking an ‘elbow’ between the scape and funicle. cf ‘geniculate antenna’.

Orthocerous genitalia (male genitalia) – see pedotectal genitalia (preferred term)

Ostiolar sclerites (male genitalia) – pair of sclerites more or less covering ostium when endophallus not everted. When everted the sclerites lie at the base of the everted endophallus on dorsal wall of penis adjacent to ostium. Synonym: ostial valves, ostial sclerite (Arzanov, 2003), endoplatten, verschlussklappe. (modified 10 June 2020)

Ostium (male genitalia) – opening of penis through which the endophallus everts.

Outer bevel (leg, tibia) – The slope on the anterior face of the tibia between the anterior apical margin (as defined by the anterior apical setal comb) and the unmodified anterior face, delimited by a transverse swelling or ridge just basal to the tibial apex bearing with a secondary setal comb. Almost always on the hind tibia only (Entiminae, Brachycerinae). See discussion on the Corbel.

Ovipositor (female genitalia) – the organ by which the eggs are laid, including gonocoxites, styli and vulva. (definition changed June 2012).

Pappolepida (scales) – scales which divide multiple times at apex to give them a velvety or feathery appearance (Brown, 2015; George et al., 2015)

Paracoila (head, mouthparts) – pouch for receiving the cardo of the maxilla near the base of the hypostomal sinus (Morimoto & Kojima, 2003).

Parameres see parameroid lobes (preferred term).

Parameral lobes (male genitalia) – see parameroid lobes.

Parameroid lobes (male genitalia) - lobes attached to the posterodorsal part of the tegminal ring. May have posteriad unsclerotised extensions termed ‘apical membranous lobes’. The parameroid lobes are not unequivocally homologous with the parameres of other Coleoptera, hence the difference in terminology. See also parameroid plate. Synonyms: parameres, parameral lobes.

Parameroid plate (male genitalia) - dorsal section of tegmen extending posteriorly. Generally comprising the parameroid lobes or a single lobe, sometimes with additional sclerites or showing membranous areas surrounded by sclerite. It is a two-layered structure, and sometimes has different sclerites on the dorsal and ventral layers.  The parameroid lobes are not unequivocally homologous with the parameres of other Coleoptera, hence the difference in terminology. See parameroid lobes, fenestrae, suprafenestral sclerites, subfenestral sclerites, prostegium. Synonyms: dorsal plate, tegminal plate, cap-piece.

Pars stridens see File.

Pectoral canal see Rostral canal.

Pectoral receptacle - see Mesothoracic receptacle.

Pedal genitalia (male genitalia) - the state found in majority of ‘Gonatoceri’, where the tectum (q.v.) is not visible, the penis body and its apodemes describe two separate curves when viewed laterally and are articulated with each other, the tegmen has two more or less distinct parameroid lobes. Compare with ‘pedotectal genitalia’ (q.v.). Synonym: gonatocerous genitalia.

Pedicel (head, antenna) - second of the three segments of the basic insect antenna (the other two being the scape and flagellum). 'Pedicel' and 'flagellum' are terms rarely if ever used in weevil taxonomy.

Pedon (male genitalia) – ventral plate of penis. See also pedotectal genitalia and tectum.

Pedotectal genitalia (male genitalia) – term describing the type of penis found in basal ‘orthocerous’ weevils. The dorsal and ventral plates of the penis body (‘tectum’ and ‘pedon’ respectively are separate for most of their length, united by a membrane, and fused at the base (c.f. tectum not visible), the apodemes and the penis body describe a smooth curve in profile (cf a double curve). The parameroid lobes are more or less fused together (cf separate). Synonym: orthocerous genitalia.

Peduncle (head) – the part of the submentum (q.v.) projecting between the maxillae and bearing the prementum (q.v.).  See discussion under labium.

Penis  (male genitalia) – the part of the male genitalia comprising the unpaired intromittent organ with its apodemes, and containing the eversable endophallus and the opening of the ductus ejaculatorius (gonopore). It is enclosed by the tegmen. The ‘body’ and apodemes (= temones, aedeagal apodemes) are sometimes compared in length as a taxonomic character.  Synonyms: median lobe; ‘aedeagus’ of some authors, including Wanat 2007.

Penis apodemes (male genitalia) – a pair of apodemes extending anteriorly from the base of the penis.  In more detail: invaginations of the post-tegminal membrane (first connecting membrane) lying anterior to the penis body, and generally connected to it by sclerotization.  The apices of the apodemes support a pair of longitudinal muscles arising dorsolaterally on the tegminal ring and a pair arising on the apex of the tegminal apodeme; these serve as protractors of the penis (Burke, 1959; Cerezke, 1964), and possibly also retractors (Cerezke, 1964).  Synonyms: aedeagal apodemes, median lobe apodemes, median struts, temones (in some cases the term ‘temones’ is applied to tegminal apodemes). [amended September 2015]

Penis body (male genitalia) – the part of the penis not including the apodemes.

Pennon (male genitalia) – fine filamentous sclerotized process within the genital pocket, fringing semi-permanent folds (visible when stained with chlorazol black) (Wanat, 2001, 2007).

Phallobase (male genitalia) – Anterior or basal part of the aedeagus from which the parameroid lobes or parameroid plate arise. See Tegmen.

Phallotreme (male genitalia) – see Gonopore.  Sometimes applied to ostium, incorrectly.

Phanerognatha (informal group of weevils) – Curculionidae characterised by the phanerognathous (qv) character state, often also known as ‘long-nosed’ weevils, and also characterised broadly by a long slender rostrum; the mandibles lack a deciduous process, the larval antenna has a more or less conical and projecting apex, and the larvae are concealed within plants. The group is not monophyletic, and has no formal status. See also ‘Adelognatha’.

Phanerognathous (head, mouthparts) – maxillae not covered by the prementum. (cf ‘adelognathous mouthparts’. Characteristic of the ‘Phanerognatha’ (qv).

Plaga – see Nasal plate.

Plectral tubercles (abdomen, tergite VII) – two or more raised tubercles on tergite VII, each with a small seta posteriorly, that act against the stridulatory file in the elytro-tergal stridulatory system (q.v.) (Lyal & King, 1996)

Pleural process - see Hypomeral lobe (preferred term).

Pleuro-sternal suture (prothorax) – see Noto-sternal suture

Pleurostomal sinus (head) – emargination of buccal cavity margin between precoila and postcoila to accommodate the base of the mandible and allow it to rotate outside the margins of the rostrum.  Shallow in Attelabidae, Scolytinae and Platypodinae, deeper in other weevils (Morimoto & Kojima, 2003).

Pleurostomal sulcus (head, rostrum) – part of subgenal sulcus dorsal to the mandible.

Postcolia (head) – the socket for the ventral (posterior) articulation of the mandibles (postartis), born on the hypostoma (q.v.). See Morimoto & Kojima (2003) [amended June 2015]

Post-coxal bridge - see Hypomeral lobe (preferred term).

Post-coxal lamellae (prothorax) – blade-like projections behind for-coxae, extending between coxa and posterior margin of prothorax, as a part of the sternal canal for the rostrum. Apomorphic for Curculionidae: Cryptorhynchinae: Aedemonini, and also for Aonychus (Erirhinini). Similar structures, anteriorly abutting the coxa and posteriorly meeting medially are found in the Camptorhinini (currently in the Cryptorhynchinae but being transferred to the Molytinae, and itself polyphyletic). Synonyms: post-coxal flanges, post-coxal walls of the pectoral canal.

Post-coxal process (prothorax) – see Hypomeral lobe (preferred term).

Posterior declivity (elytra) – distal part of elytra where, at rest, sutural margin curves ventrad towards lateral margin.

Posterior tentorial pit (head) – invaginations of the cuticle on the ventral surface of the head corresponding to the positions of the posterior tentorial arms internally. The pits mark the junction of the gular suture and the subgenal suture. They may be very difficult to see in weevils, and may be fused to a single pit or extend effectively along a single gular suture. See Lyal (1995) for a discussion.

Postgenal arm (head) – see hypostomal process.

Postgula (head) – see cervical sclerites (preferred term).

Postmentum (head) – see submentum (preferred term). Davis (2011) limits the postmentum to the projecting part of the labium supporting the prementum (peduncle, q.v.), terming the posterior part the submentum.  See discussion under labium q.v. [amended June 2015]

Postocular lobe (prothorax) – lobulate projection on the anterior margin of the pronotum, lying just behind the eye and covering it when the head is rotated ventrad. Often fringed with setae, probably having as an eye-cleaning function. Synonyms: ocular lobe; eye-flap. [amended June 2015]

Post-tegminal membrane (male genitalia) – membrane between tegmen and base of penis (Wanat, 2007). Synonym: first connecting membrane.

Praemucro (leg) - see Premucro (preferred term).

Precoila (head, mouthparts) – the socket for the dorsal (anterior) articulation of the mandibles (preartis), born on the clypeus.aThe clypeus in weevils is not separated from the frons by a suture, so cannot be distinguished.

Pregula (head) – see Submentum.

Prementum (head, mouthparts) – the anterior plate of the mentum, bearing the palpi. See discussion under Labium.

Premucro / pre-mucro (leg, tibia) – small preapical tooth arising ventrally (occasionally distally) at apex of tibia (Kuschel, 1951; Thompson, 1992), basal to mucro/uncus. It can co-exist with a mucro or uncus (i.e. is homologous with neither). It is marked by a paired tuft of long curved setae arising either side of its base and curving more or less over it. In some groups (e.g. many Lixinae, some Molytinae) it is more strongly-developed in females than males, and may be absent or very small in the latter.  Synonyms: praemucro, pre-mucro, secondary mucro. [amended December 2012]

Pretarsus (leg) – terminal segment of the leg, consisting of paired or, more rarely, single claws. See Tarsal Claw. (definition changed June 2012).

Pre-tegminal membrane (male genitalia) – membrane between 9th segment and the tegmen in males (Wanat, 2001, 2007) Synonym: second connecting membrane.

Pronotum (thorax, prothorax) – the dorsal sclerite of the prothorax.

Prorostrum (head, rostrum) - the part of the rostrum from the anterior end of the mesosrostrum (broadening above the antennal insertion) to the apex of the rostrum (Wanat, 2001). Purely a descriptive term lacking any mophological significance.

Prostegium (male genitalia) – sclerite in ventral layer of parameroid plate to which the arms between the tegminal apodeme and the parameroid lobes attach.  Present on ‘orthocerous’ weevils and forming part of tegminal ring in more derived groups. (Wanat, 2007; Kuschel, 1989). Synonym: supra-annular sclerite.

Prosternal canal (prothorax) – channel on the prosternum (basisternum and sternellum) to receive the rostrum when the head is rotated down and the rostrum lies along the ventral surface of the thorax. It may extend between the separated coxae onto the sternellum or stop at the fore coxae, thus lying along the basisternum only. See also Rostral canal.

Prosternal process (prothorax) – the part of the prosternum lying between the fore coxae (if these are separated) and extending to the hind margin of the prosternum unless interrupted by the hypomeral lobes. Comprising an anterior basisternum and a posterior sternellum which, if they meet, are separated by the sternacostal suture.

Prosternum (prothorax) – the sternal element of the prothorax, comprising an anterior basisternum and a posterior sternellum which are either separated by contiguous procoxae or, if they meet, are separated by the sternacostal suture.

Prothoracic horns (prothorax) – pair of short or long projections generally arising just anterior to fore coxae in some Baridinae and Conoderinae, used by males in fighting.

Proventriculus (alimentary canal) – posterior part of the foregut comprising eight longitudinal folds, variously sclerotised in some groups. See Kissinger (1963) and Calder (1989)

Proximal comb (leg, tibia) – see secondary comb.

Pterygium (head, rostrum) - One of the two lateral expansions on the rostrum lying above and partly concealing the scrobes in which the antennae are concealed.

Pygidium (abdomen) – One or more of the posterior abdominal tergites which are exposed by the elytra at rest and are more highly sclerotised and strengthened than the other tergites. Thompson (1992) uses a ‘tergal formula’ (TF) in which tergites concealed by the elytra are given in normal type ‘1-6’, those forming the pygidium in bold type ‘7’ and those concealed in the genital chamber in parentheses ‘(8)’.

Ramus (female genitalia, spermatheca) – the part of the spermatheca to which the spermathecal gland is attached. See Gland-lobe. [amended June 2015]

Rectal loop –oblique sclerotized band surrounding the rectum, functioning as part of the cryptonephridial system (Lyal & Favreau, 2015).

Rectal ring– transverse sclerotized ring surrounding the rectum, functioning as part of the cryptonephridial system (Lyal & Favreau, 2015).

Rectal valve – sclerotized ring or loop surrounding the rectum, functioning as part of the cryptonephridial system (Lyal & Favreau, 2015).

Rostral canal (thorax) - channel on the thoracic sterna and ventrites to receive the rostrum when the head is rotated down and the rostrum lies along the ventral surface of the thorax. On the prothorax it is generally delimited by longitudinal carinae, probably marking the pleuro-sternal suture. Synonym: pectoral canal, rostral furrow, prosternal canal. [amended July 2015]

Rostral furrow see Rostral canal (preferred term).

Rostrum (head) – the anterior part of the head, bearing the mouthparts, extended into a tube in most weevils, but may be short or absent (e.g. Scolytinae).  See more detailed discussion under Head. Wanat (2001) considers the rostrum as comprising a ‘Metarostrum’ (q.v.), ‘Mesorostrum’ (q.v.) and ‘Prorostrum’ (q.v.) (base, middle and distal) but these terms are purely descriptive and do not relate strictly to morphological homologies. Synonyms: beak, snout. [amended June 2015]

Scape (head, antenna) – the basal segment of the antenna.

Sclerolepidia (metathorax) – specialized scales arising from metaventrite along the metanepisternal suture (Lyal & King, 1996) (amended June 2015)

Scrobe (head, rostrum) - The linear depression extending generally from the antennal insertion towards the head capsule (although sometimes deflected ventrad and occasionally with an anteriad element) into which the antennal scape fits when withdrawn against the rostrum. If shallow they are sometimes termed ‘open’. [amended June 2015]

Scutellar shield (mesothorax) – the part of the mesoscutellum which is exposed between the bases of the elytra. In most weevil literature this is just referred to as ‘scutellum’ (q.v.). Synonym: scutellum (in part).

Scutellum (mesothorax) – Posterior part of mesotergum. The term is often used to refer only to the portion of the scutellum that is visible between the bases of the elytra (see ‘Scutellar shield’).  Appropriate terminology is ‘visible’ vs ‘concealed’, not ‘present’ vs ‘absent’.

Second connecting membrane (male genitalia) – see Pretegminal membrane.

Secondary mucro – see premucro.

Secondary (tibial) comb  (leg, tibia) – row of stout setae subapically on dorsal surface of the tibia just basal to the apical comb. It may join the apical comb to produce the ‘corbel’ (q.v.).

Sheath – see Horn Sheath.

Sparse (of scales) - when scales are distant from one another and not touching (see also 'separate' and cf 'dense')

Spermatheca (female genitalia) – Sac-like structure, usually sclerotised in weevils, attached by the Spermathecal Duct to the genital tract and with a Spermathecal Gland. The spermatheca may be considered as having several different areas: Gland-lobe (= ramus) from which the Spermathecal Gland arises; Duct-lobe (= collum), where the Spermathecal Duct attaches, nodulus (basal part of the spermatheca on which the gland-lobe and duct-lobe arise, cornu, the apical often curved and acuminate part. A spermathecal compressor muscle may extend between the cornu and nodulus. [amended January 2016]

Spermathecal duct (female genitalia) - duct between the spermatheca and the genital tract, usually meeting it at the junction between the common oviduct and the bursa. Variation in the position of this attachment can be useful systematically

Spermathecal Gland (female genitalia) – gland attached to the spermatheca.  After maceration the gland is largely lost, but the sac-like lumen of the gland remains, and is usually termed the ‘spermathecal gland’ in taxonomic descriptions

Spicule plates (male genitalia) – sclerites in the second connecting membrane of the genital pocket adjacent to the base of the spiculum gastrale.  In at least some cases likely to be homologous to the basal plate of the spiculum gastrale, although do not always have muscle attachments (see Clark, 1977)

Spiculum gastrale (male genitalia) – Internal apodeme of male sternite IX. Comprises a long apodeme (or manubrium) and a posterior sclerotized plate or pair of arms (basal arms). Very variable through Curculionoidea. The basal arms are fused to the genital pocket. Although derived from Sternite IX, it may not be wholly homologous with that sternite. Synonyms: urosternite, sternite IX. (edited 25 November 2011).

Spiculum relictum (male terminalia) - small pouch or apodeme sometimes invaginated between hemisternites on male sternum VIII (Thompson, 1992). Possibly serially homologous with the apodeme of sternum IX. Synonyms: false strut, false spiculum.

Spiculum ventrale (female terminalia) – internal apodeme of sternum VIII. Comprises a pair of basal arms, sometimes united to form a basal plate, and an apodeme, sometimes subsumed by the basal arms to give a V-shaped or U-shaped structure. Erbey et al (2010) termed the apodeme the 'genital spiculum'. Synonym: genital spiculum. (modified June 2012)

Spinasternum (prosternum) see Sternellum.

Sternacostal suture (thorax) – suture between basisternum and sternellum. See Davis (2009).

Sternellum (thorax) - the second sclerite of the ventral part of each thoracic segment. In weevils it is generally distinct on the prothorax, forming for example the posterior part of the canal in Cryptorhynchinae and a small clear sclerite just behind and between the fore coxae in most others. On the mesothorax it is rarely if ever distinct, but would lie between the mid coxae. On the metathorax it is small and lies between the hind coxae, if discernible. Wood (2007-14; after Hopkins, 1909) figures the sternellum for each thoracic segment. The sclerite on the prothorax has also been called the ‘furcasternum’ and ‘spinasternum’; homologising sclerites in this complex area is difficult.  See the discussion on Characters and character-states: "Sternellum or Prosternal process" for further information and a terminological issue. Synonyms: 'furcasternum', 'spinasternum'.

Sternite IX (male genitalia) – see spiculum gastrale.

Sternite VIII (female genitalia) – see spiculum ventrale.

Striae – see elytral striae.

Stridulatory file – see file.

Stridulatory rasp – see file

Stylus (female genitalia) - a distal segment borne by the Gonocoxite (q.v.) in most species. Generally bears setae, and rarely 'lost' or fused to the Gonocoxite (see 'coxite-stylus'). Synonym: gonostylus.

Subfenestral sclerites (male genitalia) – sclerotised transverse sclerite adjacent to parameriod lobe anterior to an unsclerotsed area (fenestrae (q.v.) of the parameroid plate (q.v.). Homology across Curculionoidea is unlikely. See Wanat (2007).

Subgenal sulcus  (head, rostrum) – sulcus on the ventral surface of the adult weevil head running between the anterior tentorial pits to the posterior tentorial pits. Synonyms: subgenal suture; pleurostomal sulcus + hypostomal sulcus.

Subgenal suture (head, rostrum) – see Subgenal sulcus (preferred term).

Subgeniculate antenna - state in some Apionidae where the apical part of the scape is sharply curved, causing the funicle to lie at an angle to the long axis of the scape, giving the impression of the geniculate state (q.v.) (Wanat, 2001).

Submarginal fold (elytra) - longitudinal furrow and carina internally on elytron close to costal margin, widening basally. The deeper wider "Basal pocket" of the fold fits over the raised sides of ventrite 1 + 2, and the metepisternite, the posterior part locks over the other abdominal ventrites. The particularly broad basal part has been used as a character of the Baridinae + Conoderinae + Ceutorhychinae.

Submentum (head, rostrum) – the posterior plate of the labium, posteriorly meeting the gula at the level of the posterior tentorial pits (q.v.) and anteriorly meeting the prementum. Within the Curculionoidea there is no separate mentum (median plate of the labium) but the submentum cannot be unequivocally synonymised with the submentum of other Coleoptera (where the mentum is present) or the more plesiomorphic postmentum of other insects. Davis (2011) distinguishes a postmentum (the anteriorly projecting part of the fused mentum + submentum) and the submentum, which lies between that and the posterior tentorial pits. Discussed by Lyal (1995), Morimoto & Kojima (2003) and Davis (2011). See discussion under Labium. Synonyms: postmentum; pregula.

Supra-annular sclerite (male genitalia) – see Prostegium.

Suprafenestral sclerites (male genitalia) – sclerotised transverse sclerite adjacent to parameriod lobe posterior to an unsclerotsed area (fenestrae (q.v.) of the parameroid plate (q.v.). Homology across Curculionoidea is unlikely. See Wanat (2007).

Tarsal groove (leg, tibia) – furrow on the apico-ventral surface to receive the tarsus if folded back along the leg.

Tarsal Claw (leg, tarsus) - paired claws at the apex of the tarsus. They may be simple (more or less gradually tapering from base to apex and lacking teeth or other projections), appendiculate (with a ventral tooth or other projection arising in the basal third, often arising from a process apparently splitting off from the claw, and sometimes directed between the claws), toothed or bifid (with the apex 'doubled' - split from the middle of the claw or nearer the apex to provide two teeth for each claw, one generally shorter than the other). Synonym: pretarsus.

Tarsomere (leg, tarsus) - the individual portion of a tarsus. There are five tarsomeres in the weevil tarsus, although the fourth is very small and often hidden between the lobes of the third, hence the description 'pseudotetramerous'. The only exception is the Raymondionymidae, where there are four tarsomeres only. See also fifth tarsomere; the fifth tarsomere is sometimes termed the onychium, although as this term is sometimes also used for the claws themselves, it is best avoided.  Synonym: tarsal segment. [amended June 2015]

Tectum (male genitalia) – dorsal plate of penis, when present. See also pedon and pedotectal genitalia.

Tegmen (male genitalia) - Anterior or basal part of the aedeagus, comprising a more or less complex ring or sheath surrounding the penis (q.v.), a ventral apodeme directed anteriad (see 'apodeme of tegmen') and dorsal parameroid lobes (q.v.) or parameroid plate (q.v.). The shape of the tegmen, and particularly of the parameroid lobes / plate differs between the pedal and pedotectal type of aedeagus. Synonym: phallobase (in part). [amended June 2012]

Tegmenal (in conjunction with ring, apodeme etc) - see Tegminal.

Tegminal apodeme (male genitalia) - apodeme extending anteriad from base of tegmen ventrally.  Wanat (2007) refers to the ‘basal piece’ as comprising the apodeme and arms curving round the side of the penis and meeting a dorsal plate (tegminal plate), and an equivalent concept is used by Lawrence et al. (2010). Synonyms: Apodeme of tegmen, manubrium, tegminal strut, basal piece (in some cases).  [amended September 2015]

Tegminal plate (male genitalia) – see Parameroid plate.

Tegminal ring (male genitalia) – the part of the tegmen that forms a more or less complete ring around the penis, from which arise the parameroid lobes or plate and the tegminal apodeme.  Synonym: basal piece (in some cases).

Tegminal strut (male genitalia) – see Tegminal apodeme, Manubrium.

Temones (male genitalia) – see penis apodemes. Term used by Alonso-Zarazaga, 1989, 1990.

Temple (head, head capsule) - lateral part of the head between the posterior margin of the eye and the margin of the pronotum (Wanat, 2001). See discussion under Head.

Tentorium (head) – internal skeleton of the head, comprising plesiomorphically a pair of anterior arms joined to a pair of posterior arms, these united by a tentorial bridge.  The anterior and posterior arms are apodemal invaginations arising at the anterior tentorial pits and posterior tentorial pits respectively. Discussed by Lyal (1995).

Tergal formula (abdomen) – see under Pygidium.

Tessellate (of scales) - scales pressed together and obscuring the cuticle but not overlapping (cf 'imbricate').

Tormae (larva, mouthparts) - sclerotized rods in the labrum. Their shape can provide taxonomically-useful characters. Synonym: labral rods.

Transfer apparatus  (male genitalia, endophallus) – see  copulatory sclerites

True corbel – see discussion under corbel.

Uncus (leg, tibia) - Apical tooth of the tibia associated with the Inner Flange (q.v.). The traditional distinction between the uncus and the mucro (q.v.) is that the mucro arises from the ventral (inner) apical angle and is not continuous with the dorsal (outer) margin), while the uncus arises from, or is continuous with, the dorsal margin (Marvaldi & Lanteri, 2005). Thompson (1992) notes that the uncus is always associated with the inner flange, so that a mucro, once associated with the inner flange, is termed an uncus. There are cases where the flange and the mucro do not smoothly connect, even where both are present.

Unguitractor - see Fifth tarsomere (preferred term).

Urosternite - see spiculum gastrale (preferred term).

Vagina (female genitalia) – tubular part of the ovipositor between the junction with the common oviduct and the gonocoxites, where it opens through the vulva.

Vaginal palp see 'coxite-stylus'.

Venter (abdomen) – the visible ventral surface of the abdomen.

Venter (head, head capsule) - area between the eyes ventrally, limited anteriorly by the base of the rostrum (level of the anterior margin of the eyes) and posteriorly by the posterior tentorial pit. Includes part of the submentum sensu Lyal, 1995 and part of the postgena. (Wanat, 2001). There is potential to confuse this use of the term with the more common use as applied to the ventral surface of the abdomen, and it is not in general use.

Ventral sulci (head, rostrum) - (Wanat, 2001).

Ventrite (abdomen) – visible (exposed) abdominal sternites.  The first two sternites are concealed, forming part of the coxal cavity, so that the first ventrite is the third sternite. There are five ventrites visible in weevils. The nature of the sutures between the ventrites is discussed by Thompson (1992).

Vertex (head, head capsule) - posterior part of the head, extending from the occiput to the level of the antennal insertions.  It, and its subdivisions, are discussed under the entry on Head.  Some authors limit the term to the area behind the eyes dorsally, not including the part of the head capsule normally covered by the pronotum (i.e. lacking the sculpture and setation of the more normally exposed part of the head) [amended June 2015]

Vulva (female genitalia) – opening of vagina between gonocoxites.

Wing-binding patch (abdomen) – patch of very fine spines generally found paired on abdominal sterna, used by the weevil in folding the wings under the elytra.

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