Sphaeritidae, Synteliidae in Handbook of Zoology Ed. 2
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/303315478 Sphaeritidae, Synteliidae in Handbook of Zoology Ed. 2 Chapter · March 2016 CITATIONS READS 0 224 1 author: Alfred Francis Newton Field Museum of Natural History 114 PUBLICATIONS 3,385 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Beetles in deep time and more View project Taxonomic Catalog of the Brazilian Fauna - Staphylinidae (Coleoptera) View project All content following this page was uploaded by Alfred Francis Newton on 18 May 2016. The user has requested enhancement of the downloaded file. 274 13 Histeroidea Gyllenhal, 1808 Alfred F. Newton 13.1 Sphaeritidae Shuckard, 1839 Distribution. The family includes a single genus, Spha erites Duftschmid, confined to temperate forested or alpine areas of the northern hemisphere. The six known species include two rather widely distributed species: Sphaerites glabratus (Fabricius), widespread across nort- hern Great Britain, northern Europe, and east to Mongo- lia, eastern Russia, Japan and China (Jilin); and S. politus Mannerheim from western North America (southeastern Alaska to northern California, east to Alberta, Idaho and Fig. 13.1: Sphaerites dimidiatus Jureček. Scale line = 2.0 mm. Photo © Peter W. Kovarik. western Montana) and possibly (doubtfully according to Löbl 1996) eastern Russia and Japan (Kryzhanovsky 1989; Löbl 1996; Newton 2000). The remaining four species are similar prey. Like histerids, Sphaerites adults feign death known from only a few localities in central China: S. dimi when disturbed (P. Kovarik pers. comm.). diatus Jureček, from Gansu, Shaanxi, and Sichuan provin- ces; S. involatilis Gusakov from Sichuan; S. nitidus Löbl Morphology, Adults (Fig. 13.1). Length about 4.5–7 mm; from Gansu and Sichuan provinces; and S. opacus Löbl & body broadly oval, convex; color black (elytra partly red Háva from Shaanxi province (Löbl 1996; Löbl & Háva 2002; in two Chinese species), moderately shining with slight Gusakov 2004; Háva 2014). blue-green metallic reflection; vestiture generally absent except on appendages. Biology and Ecology. These usually rare beetles are Head less than half as wide as pronotum, deflexed generally associated with decaying organic matter such as but not retractile, without differentiated neck, surface dung, carrion, fungi, fermenting fruit, and sap of dying or punctate; eyes large, oval. Epistomal suture present, dead trees and stumps, but their ecology is poorly known broadly curved or more or less angulate and with short and the full life cycle has not been observed in detail medial stem (i.e. Y-shaped). Antenna short, weakly geni- (Newton 2000). Sphaerites glabratus has been associa- culate, inserted under slight frontal ridge between eye and ted especially with northern conifer forests, sometimes at mandibular base, antenna in repose bent under head; of high altitudes; adults are attracted to sap flows on birch 11 antennomeres, scape long and moderately curved; stumps, and have been observed to feed on the sap and antennomeres 2–8 small, each with or without a few large mate there; females laid eggs in nearby sap-impregnat ed setae, 8 flattened and appressed against 9; 9–11 together soil, and larvae developed quickly with the next genera- forming a large densely setose club, the antennomeres tion of adults emerging within a month (Nikitsky 1976). In distinct but immoveably associated, antennomere 11 with North America, S. politus can be locally common at carrion a pair of internal vesicles. Labrum short, strongly trans- (Keen 1895), but has been found also in bear dung and verse with straight anterior edge and rounded anterior in or near compost (Hatch 1961), and in unbaited pitfall angles, with two adjacent very long setae near each side; and flight traps in old-growth conifer forests (M. Ivie pers. underside and epipharynx with dense setae or microtri- comm.); in Japan, this species (but possibly misidentified, chia. Mandibles elongate, strongly projecting, with con- see Löbl 1996) has been collected in pitfall traps in Pinus tiguous molar areas at base, each mandible with a large forests at 1800–1980 m elevation (Ôhara 1994). The four medially curved acute apex, 1–2 strong subapical teeth, Chinese species have all been found at high elevations and a setose prostheca that is more than 2/3 as long as the (2800–3600 m) in the mountains, in one case (S. dimidi mandible. Maxilla with densely setose galea and lacinia, atus) in scree in an alpine meadow (Löbl & Háva 2002). the latter at apex with a pair of strong non-articulat ed Larval feeding was not reported by Nikitsky (1976), medially curved teeth, the palpus of four palpomeres, the and his report of adults feeding on sap requires confirma- first very small, the remaining segments stout, the apical tion. The mouthparts of larvae as well as adults are similar palpomere longest, cylindrical or slightly depressed. to those of histerids known to be predaceous on soft prey Labium with densely setose hypopharynx and bilobed such as Diptera larvae, and it seems likely that both stages ligula; palpigers small, lightly sclerotized, separate; palp of Sphaerites are also mainly or strictly predaceous on of three palpomeres, the apical palpomere longest and Authenticated | [email protected] Download Date | 4/18/16 9:25 PM 13.1 Sphaeritidae Shuckard, 1839 275 stoutest; mentum sexually dimorphic: trapezoidal, flat asymmetrical ring; parameres long, nearly completely fused and well sclerotized in female, transversely oval, slightly to one another and largely enclosing the slender median lobe. concave and translucent in male. Gular sutures complete, Female terga VIII–IX divided, X entire and situated between well separated throughout. Tentorium: see Stickney (1923). halves of IX, sternum VIII divided; ovipositor consisting of Prothorax freely movable, not tightly co-adapted to paired valvifers and heavily sclerotized coxites, the latter rest of thorax. Pronotum transverse, broadly emarginate each with a scoop-like outer surface and a small stylus on anteriorly, sides evenly convex and broader posteriorly, inner side; spermatheca simple, bulbous. [General reviews base sinuate, sides strongly and anterior border weakly and illustrations of adult morphology of Sphaerites can be margined, surface punctate especially laterally; hypome- found in Kryzhanovsky & Reichardt (1976) and especially ron broad, explanate, with long acute postcoxal process Ôhara (1994), with further details in Hansen (1997; oviposi- that does not close the procoxal cavities; notosternal tor), Stickney (1923; head capsule), Williams (1938; mouth- suture complete; prosternum short, with small fingerlike parts), Forbes (1926; wing folding pattern), Kukalová-Peck & intercoxal process that fits into groove in coxae but does Lawrence (1993; wing venation with modern terminology), not separate the apices of the coxae. Scutellum modera- and Crowson (1974; internal anatomy)]. tely large, subtriangular; mesoventrite short, with eleva- ted intercoxal plate; mesanepisternal and mesepimeral Morphology, Larvae. Body elongate, slightly flattened, sutures complete. Elytra convex, long but abruptly trun- surfaces very lightly to moderately pigmented and sclero- cate, exposing only pygidium (abdominal tergum VII); tized, generally smooth, with sparse vestiture. striae represented by nine unimpressed rows of punctu- Head prognathous, protracted, strongly transverse, res which become more or less irregular or obsolescent without distinct neck; epicranial sutures (dorsal ecdysial near base and apex; epipleural fold present, complete. lines) separate, without basal stem; stemmata apparently Metathoracic wings present, with large anal lobe and absent. Antenna less than half as long as head width, relatively complete venation including distinct radial of three segments, pair of sensoria of second segment cell and large RP-MP1+2 loop (former “M-Cu” loop); see conical and situated on outer apex, lateral to insertion Kukalová-Peck & Lawrence (1993: fig. 41) for details and of apical segment. Labrum fused to head capsule to form modern venational terminology, but note that MP1+2 is a nasale bearing a single median tooth. Mandibles more mislabeled MA1+2 there. Metaventrite long, metanepis- or less symmetrical, each with a prominent curved acute ternal and metepimeral sutures complete; metendoster- apex, a single acute tooth medially, and an abruptly enlar- nite with long basal stalk and pairs of long furcal and ged base that bears a penicillus or tuft of setae. Maxillary short anterior arms. Legs with pro- and mesotrochantins groove absent. Cardines distinct, transverse, separated exposed; anterior coxae transverse, contiguous, pro- by mentum; stipes elongate, without apical lobes; palp minent; middle coxae small, globular, well separated 4-segmented, basal segment with an articulated digiti- by elevated plate of mesoventrite plus flat metasternal form appendage on inner side. Labium consisting of pre- process; hind coxae transverse, subcontiguous; trochan- mentum, membranous mentum, and a submentum that ters small; femora swollen; tibiae relatively robust with is fully integrated in the ventral wall of the head capsule; small spines along outer edge but without teeth; tarsi ligula absent; palps 2-segmented, separated by less than all 5-segmented, tarsomeres slender with a few setae on the width of one of them. Gula present, elongate. each; apical tarsomere bearing a pair