FNZ 48 - Scaphidiinae (Insecta: Coleoptera: Staphylinidae) - Morphology
Löbl, I; Leschen, RAB 2003. Scaphidiinae (Insecta: Coleoptera: Staphylinidae). Fauna of New Zealand 48, 94 pages.
(
ISSN 0111-5383 (print),
;
no.
48.
ISBN 0-478-09353-5 (print),
).
Published 18 Nov 2003
ZooBank: http://zoobank.org/References/FDA38B33-D656-46CB-9406-CA03D26DC811
Morphology
For gross structure we adopt the terminology used by Lawrence & Britton (1991) and Lawrence et al . (1999), and for some of the specific terms for scaphidiine characters used for identification we used the terminology discussed in Leschen et al . (1990) and that used traditionally by staphylinid workers. Many structures listed below are labelled in the following figures: ventral body (Fig. 1), dorsal body (Fig. 2), aedeagus (Fig. 20, 21, 35, 36).
SURFACE AND INTERNAL CUTICULAR FEATURES
Fovea: invaginations of the cuticle often having internal setae. These are present only on the hypomeron of Notonewtonia (Fig. 8, 9).
Microsculpture: small cuticular surface features in the form of transverse lines or small pits or punctures. Punctate microsculpture in Scaphisoma consists of transverse combs that are clearly visible in SEM, but are not apparent on pinned specimens.
Punctures: pit-like impressions that extend shallowly into the cuticle and are often marked by a seta and/or a pore.
Setae: hair-like extensions of the cuticle.
HEAD AND ITS APPENDAGES
Antenna: consisting of 11 antennomeres including a 5-segmented club; the form of the antennae are clavate ( Cyparium , Fig. 2, 3) or filiform with a loosely articulated club (remaining taxa, see Fig. 4-19); antennomere 3 is usually elongate (Fig. 84) or occasionally short and triangular (Fig. 17-19); antennomere 11 is elongate in Baeocera actuosa (Fig. 85).
Frons: anterodorsal portion of the head between the eyes. The distance separating the eyes is referred to as the interocular space.
Labium: ventral mouthparts that include the mentum, ligula, prementum, and labial palpi (Fig. 76, 79, 82, 86, 87, 90).
Mandible: dorsoventrally flattened appendage consisting mainly of apical teeth, a membranous prostheca, and a basal striate mola (Fig. 74, 77, 80).
Maxilla: tripartite appendage located below the mandible consisting of an outer palp of 3 segments (palpomeres) and a palpiger, a middle galea, and inner lacinia (Fig. 75, 78, 81, 86, 88, 89). The shape of the terminal palpomere is an important feature that is used to discriminate among scaphidiine genera; an aciculate palpomere is shown in Fig. 87 whereas a normal (or tapering) palpomere is shown in Fig. 81.
Mentum: posterior sclerite of the labium.
Tentorium: internal structure (endocarina) which may have an anterior median spine(s) arising from a bridge-like corporotentorium.
THORAX
Corbiculum: Internal setose structure derived from the prothoracic spiracle and consisting of internaly directed setae and an outer membrane with distinct pores (Fig. 91-95).
Pronotum: dorsal sclerite of the prothorax consisting of a disc (middle portion of the structure), lateral carinae, hypomera (the deflexed portions of the pronotum), posterior pronotal lobe (the posterior lobe that often projects behind to cover the scutellum), and posterior or basal angles.
Prosternum: ventral portion of the prothorax which is reduced in scaphidiines; a spine may be present (Fig. 96).
PTEROTHORAX
Mesoventrite: ventral portion of the mesothorax that meets the metaventrite posteriorly between the mesocoxae (Fig. 98), articulating with the metaventrite by means of an internal articulation which may be absent due to fusion, and posteriolaterally marked by the anapleural line; anterior structures include the prepectus (=mesosternal space) and procoxal rests (Fig. 97); mesal structures include a paxillum, and mesoventral, secondary, and medial lines.
A "mesepimeron" may be present in front of the anapleural line, but this may not be homologous to a true mesepimeron (Leschen et al . 1990). A well-developed mesotrochantin and mesepimeron are present in apateticines and other members of the oxyteline group, but in scaphidiines the mesotrochantin is lost, either by fusion with the coxa, or through incorporation with the ventrites (possibly as the "mesepimeron"). What is present, and visible externally, is a well-defined sclerite in Scaphiini and Scaphidiini, which is present or absent in Scaphisomatini but absent in Cypariini. A well-developed mesepimeron is usually marked internally by a ridge, but in Scaphisomatini this is not true and we refer to this structure as the mesepimeral line.
Metaventrite: ventral portion of the metathorax, which articulates anteriorly with the mesoventrite by an intercoxal process (which may be fused with the mesoventrite), and posteriorly with the first ventrite of the abdomen and may have a median discrimen or longitudinal groove, distinct primary setae, mesocoxal lines (=femoral or submesocoxal lines), premetacoxal lines on the external surface, and a metacoxal process which may also give rise to an intercoxal plate resting between the metacoxae. The space enclosed by the mesocoxal lines is called the mesocoxal area. The metaventrite may also have setiferous sex patches in males of some species. The metendosternite is an internally bifurcate structure which functions in muscle attachment; dorsal arms may branch distal or proximal to the base.
Metepimeron: pleural region of the metathorax.
Scutellum: portion of the pteronotum that is usually visible between the elytral bases; but may be reduced or hidden (e.g., Fig. 2, 4-7).
ABDOMEN
Abdominal ventrite 1: first abdominal ventrite which may have a metacoxal bead (not shown) along the anterior margin, metacoxal lines (=submetacoxal lines), and primary setae; the area between the metacoxal lines and the anterior portion of the ventrite is the metacoxal area (the metacoxal interval is the distance between the metacoxal line and the anterior portion of the ventrite); the abdominal process is an anterior extension present between the metacoxae and sometimes having a transverse line (Fig. 99).
Aedeagus: male intromittent organ of the trilobed type whereby the phallobase (=tegmen) is reduced, as in most staphylinids, and the articulated parameres attach to the basal bulb; there is a median lobe consisting of a larger, bulbous proximal part and a narrow apical lobe, and an internal sac (Fig. 22) which contains various sclerites within it, mainly the flagellum and guide sclerite. The flagellum is the sclerotised part of the ejaculatory duct (Fig. 36, 48), which is mainly membranous (many species lack sclerites in the internal sac). Sometimes the membranous duct can be traced within the flagellum, but often not, and so the term may be not always be correctly applied. The flagellum may be partly fused with, or completely isolated from, other sclerites within the internal sac. Other elongate sclerites contained in the internal sac may not be true flagella, for example the elongate sclerites in Brachynopus (Fig. 26-29) have no obvious duct within them and are not called flagella, whereas those in Baeocera do (the membranous duct is illustrated in Fig. 36). In some Baeocera the basal part of the ejaculatory duct is clearly visible (Fig. 48, 51) but this is rarely seen in other genera. Guide sclerites (Fig. 36, 48) are present only in some groups of Baeocera .
Intersegmental membranes: membranes present between the abdominal ventrites that may have a brick-wall pattern (Fig. 100).
Ovipositor: female genitalia and egg laying structure consisting of paired basal gonocoxites usually with an apical gonostyle or stylus (Fig. 101, 102); the gonocoxite of Baeocera actuosa is hook-like with a subapical stylus (Fig. 103).
Paratergites: pleural elements that surround the abdominal terga.
Spiracles: spiracles are present in the dorsal (tergal) membranes and may be absent from the apical abdominal terga.
BODY APPENDAGES
Elytron: hardened forewing consisting of a dorsal disc which may have well-developed longitudinal striae consisting of punctures and with a lateral epipleuron which is clearly visible in lateral or ventral view; lateral, basal, and sutural (=parasutural) striae may be present, and may be contiguous, although the epipleural stria is absent in some specimens of Baeocera epipleuralis (Fig. 12); the supra-epipleural area is the space between the epipleural and lateral lines.
Hind wings: typically well developed in most taxa, but reduced in others.
Legs: consisting of the basal coxa (with a small trochantin that is hidden) (Fig. 96, 104), a short trochanter, elongate femur (Fig. 105, 106) and tibia (Fig. 107-109), and 5-segmented tarsus (Fig. 110), with tarsomere 5 having a well-developed empodium (Fig. 112), empodial setae which may number 0, 1 (Fig. 112), or 2 (Fig. 111), and tarsal claws. A triangulate process may be present at the apex of the metacoxa (Fig. 104); a well-defined ctenidium (row of setae) may be present on the profemur (Fig. 105), and males have tenent setae on the protarsus (Fig. 110) and sometimes the mesotarsus.