Revision of Glossary of Weevil Characters from Mon, 2010-02-22 23:31

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. Please comment and add to the contents, which I shall revise regularly.

Chris


Aedeagus
(= median lobe) (male genitalia) – the part of the male genitalia comprising the unpaired intromittent organ with its apodemes.

Anapleural suture (metathorax) – see metepisternal suture.

Antenna (head) - sensory projection from rostrum, comprising 11 articles: scape, 7-segmented funicle and 3-segmented club). 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)

Antennomere (=antennal article, antennal segment) (head, antenna) – term not often used in weevils, but refers to the individual parts of the funicle and club, apart form the pedicel, which is a true segment (the term pedicel is rarely if ever used in weevil taxonomy).

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

Bursa (=bursa copulatorix) (female genitalia) – large membranous lobe of female genitalia branching from vagina generally at same point as common oviduct and spermathecal duct.

Club (head, antenna) - the apical antennomeres of the antenna. The club generally has three antennomeres, either separate as in some basal groups or combined as in most Curculionoidea. In many weevils there appear to be 4 antennomeres, each delimited by a sutire and each bearing a ring of elongate setae. However, the form of the grove between the apical 'segment' and the others differs from that between the true antennomeres (Wanat, 2001). The apparent 4-article club has been termed 'pseudotetramerous' by Wanat, 2001. Key character states: loose: articulation between antennomeres and 'antennomere' neck' visible; compact: articulation and basal constrictions not seen, but borders between antennomeres clearly visible; connate: borders or sutures between antennomeres partly or completely lost. (Wanat, 2001)

Connate - of two segments or other articulating parts of the body. Fused together, with or without a line marking the original suture between them.

Coxites (=hemisternites) (female genitalia) - pair of conical sclerites apically on ovipositor, surrounding vulva.

Ductus ejaculatorius (male genitalia) – duct between the testes and endophallus.


Elytro-tergal stridulation mechanism
(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).

Endophallus (= median lobe) (male genitalia) – membranous sac lying within aedeagus condiguous with ductus ejaculatorius and aedeagus. Everts during copulation.

File (= elytral file, elytral strigil) (elytra – elytro-tergal stridulation mechanism) – patch of fine, parallel ridges on the internal surface of the elytra, generally near the apex, which form part of the elytro-tergal stridulation mechanism.

Flagellum (male genitalia) – long sclerites sometimes present within endophallus through which ductus ejaculatorius opens.

Frons (head, head capsule) - area between the eyes

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


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

Genital pocket (male genitalia) –, membranous invagination between tergum VIII and sternum VIII and to which speculum gastrale is attached. It includes both genital opening and rectum.

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

Gular suture (head, head capsule – rostrum) - suture or pair of sutures extending from the posterior margin of the head capsule to the tentorial pit(s).

Hemisternites (female genitalia) – see coxites.

Hemistrnites (male genitalia) – pair of sclerites on sternum VIII

Humerus (= humeral angle) (mesothorax, elytra) – anterolateral angle of folded elytron, sometimes produced. Tends to be rounded and effectively losy in apterous species.

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

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

Interocular pit (head) – abrupt depression on dorsum of head, between eyes.

Internal sac (male genitalia) – see endophallus.

Interstriae (elytra) – raised longitudinal strips on elytra between striae, numbered for the sutural margin outwards.

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

Mandibles (head, mouthparts) - 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 - with teeth on the apical margin of the mandible and the mandibles not opening beyond the lateral margins of the rostrum.

Manubrium (=apodeme of tegmen) (male genitalia) – apodeme extending anteriad from base of tegmen.

Median lobe – see aedeagus
Mesepimeron (mesothorax) – sclerite on the side of mesothorax (Fig. xxx)

Mesepisternum (mesothorax) – sclerite on the side of mesothorax (Fig. xxx)

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).

Mesosternal canal (= mesosternal channel) (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 mesosternal receptacle)

Mesothoracic receptacle (= mesothoracic cup) (thorax, Mesosternum) – 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.

Mesoventrite (= Mesosternum) (thorax, mesothorax) - fused preepisternum and basisternum (Wanat, 2001)

Metarostrum (head, rostrum) - basal part of rostrum, from base to widening above antennal insertion (Wanat, 2001).

Metasternal 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.

Metepisternal suture (= anapleural suture) (metathorax) – suture between metasternum and metepisternum. In cross-section metasternal 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 metasternum. The suture may be lost in flightless weevils. (Lyal et al., 2006)

Ocular lobes (prothorax) – see postocular lobe
Ostiolar sclerites (male genitalia) – pair of sclerites on forsal wall of aedeagus adjacent to ostium

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

Parameres – see parameroid lobes

Parameroid lobes (= parameres) (male genitalia) lobes attached to the posterodorsal part of the tegminal ring.

Pectoral canal - see ‘Rostral canal’

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

Plectral tubercles (abdomen, tergite VII) –

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

Post-coxal lamellae (= post=coxal flanges, post-coxal walls of the pectoral canal) (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).

Postocular lobes (= ocular lobes) (prothorax) – lobulate projections on the anterior margin of the pronotum, lying just behind the eyes and covering them when the head is folded ventrad. Often fringed with setae.

Prementum (head, mouthparts) –

Premucro (leg, tibia) – small apical tooth arising from ventro-apical angle of tibia.

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)

Prosternal canal (prothorax) – channel on the prosternum 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.

Rostral canal (= pectoral canal) (thorax) - channel on the thoracic sterna to receive the rostrum when the head is rotated down and the rostrum lies along the ventral surface of the thorax.

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

Sclerolepidia (metathorax) – specialized scales arising from metasternum along episternal suture (Lyal & King, 1996)

Scrobe (head, rostrum) - The sharp 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.

Spiculum gastrale (male genitalia) – Apodeme of male sternite IX (?). Comprises a long apodeme and a posterior sclerotised plate or pair of arms. Very variable through Curculionoidea. The apical arms are fused to the genital pocket. Although derived from Sternum IX, it may not be wholly homologous with that sternum.

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

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 discernable. Wood (2007-14), after Hopkins, 1909) figures the sternellum for each thoracic segment.

Subgenal sulci (= subgenal sutures) (head, rostrum) –

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)

Submentum (head, rostrum) –

Tegmen (male genitalia) - ring surrounding aedeagus, comprising dorsal parameres and a ventral apodeme.

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

Thoracic horns (prothorax) - anteriorly-directed horns arising from the prothorax ventrally, just anterior to the coxal cavity.  Often with a median more or less forked sheath between them.   Image below is of a thorax viewed from the ventro-posterior aspect, with the sheath pointing  towards the viewer and the horns pointing away.

Thorax of Ternova lineatosignata, viewed internally from posterior

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)

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

Vertex (head, head capsule) - 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)

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.

Comments

public://pictures/picture-68-1596563078.jpeg
Submitted by JCGiron on

I have recently finished the description of 11 new species of the Caribbean genus Apodrosus (visit:http://apodrosus.blogspot.com/) and it was a lot of work to get to learn about the appropriate literature, as the terms used to describe particular structures.
In my descriptions I used:

- Vaurie, P. (1963) A revision of the South American genus Hyphantus (Coleoptera, Curculionidae, Otiorhynchinae). Bulletin of the American Museum of Natural History 125: 239–304. To describe the apex of the rostrum (nasal plate and epistome).

- Ting, P. (1936) The mouth parts of the coleopterous group Rhynchophora. Microentomology 1: 93–114. and - Morimoto, K., Kojima, H. (2003) Morphologic characters of the weevil head and phylogenetic implications (Coleoptera, Curculionoidea). Eskaia 43: 133–169. For the mouthparts (particularly parts of the maxilla).

- Velázquez de Castro, A.J. (1998) Morphology and taxonomy of the genus Sitona Germar, 1817. (I): the metendosternite (Coleoptera: Curculionidae). In: Colonnelli, E., Louw, S. & Osella, G. (Eds) Taxonomy, ecology and distribution of Curculionoidea (Coleoptera: Polyphaga). For the parts of the metendosternite.

- Zherikhin, V.V. & Gratshev, V.G. (1995) A comparative study of the hind wing venation of the superfamily Curculionoidea, with phylogenetic implications. In: Pakaluk, J. & Ślipiński, S.A. (Eds) Biology, phylogeny, and classification of Coleoptera: papers celebrating the 80th birthday of Roy A. Crowson, volume 2. Muzeum i Instytut Zoologii PAN, Warszawa, Poland, pp. 633–777. For the wing venation.

- Thompson, R. T. (1992). Observations on the morphology and classification of weevils (Coleoptera, Curculionoidea) with a key to major groups. Journal of Natural History 26: 835–891. For the tibial apices and abdominal segments

- Howden, A.T. (1995) Structures related to oviposition in Curculionoidea. Memoirs of the Entomological Society of Washington 14: 53–102. and
- Velázquez de Castro, A. J. (1997) Estudio morfológico y taxonómico del género Sitona Germar, 1817 (Coleoptera, Curculionidae). Ph.D. thesis, Universidad Complutense de Madrid, Madrid, Spain, 495 pp. To describe structures of the female genitalia.

- Wanat, M. (2007) Alignment and homology of male terminalia in Curculionoidea and other Coleoptera. Invertebrate Systematics 21:147–171. To describe the male genitalia.

Most of this resources came as photocopies from my advisor, Dr. Nico Franz and I don't really know if they are available online... It would be another good purpose for this website: to store electronic copies of important bibliographic sources about morphology.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith