Quedius spelaeus subsp. spelaeus, spelaeus Horn 1871, Horn, 1871

Moseley, Max, Klimaszewski, Jan & Majka, Christopher G., 2006, Description of the pupa and observations on the distribution, ecology, and life history of Quedius spelaeus spelaeus Horn (Coleoptera: Staphylinidae) in Nova Scotia, Canada, Zootaxa 1226 (1), pp. 61-68 : 63-65

Results

Description: Pupa

Pupa obtect ( Figures 1–3 ), with appendages adhering closely to the body. Body strongly sclerotized; length (without abdominal processes) approximately 7.3 mm; width 2.8 mm; color pale­reddish brown (alcohol preserved specimen). Head directed ventrally towards thorax; width (between eyes) 1.6 mm, length 2.9 mm. Antennae curved and extending to approximately the apex of mesotibae. Pronotum 1.9 mm wide and 1.8 mm long; anterior margin without spines. Mesonotum broader than long; metanotum narrower than mesonotum, anterior margin deeply bisinuate with two lobes directed anteriad. Wings extending to ventral side. Tibiae directed obliquely towards middle of body. Meso­ and metatibiae with several tubercle­like protuberances; metatarsi extending to mid­point of the third visible (actually fifth) abdominal sternite. Abdomen distinctly dorso­ventrally flattened with margins of tergites slightly reflexed; nine tergites and seven sternites visible, narrowed at tergite IV. Spines located at midpoint of lateral margins of abdominal segments II–VIII rather long (~ 0.15 mm). Median tergites (III–VI) 0.5 mm long. Functional spiracles, on elevated tubercles located circa 0.10 mm from the lateral margins of the tergites, visible on tergites I–IV; apparently atrophied spiracles visible on tergites V–VII. Terminal abdominal segment sexually dimorphic as in other Quedius pupae ( Staniec 1996, 1999, 2003) with four spines on the female and two on the male.

The pupa is similar in all essential respects to other pupae in the genus Quedius ( Q. (Raphirus) fumatus (Stephens) , Q. (Raphirus) humeralis Stephens , Q. (Quedionuchus) plagiatus Mannerheim , Q. (Microsaurus) mesomelinus (Marsham) , Q. (M.) brevicornis (Thompson) , and Q. (Quedius) fuliginosus (Gravenhorst)) as described by Staniec (1996, 1999, 2003). Quedius s. spelaeus (in the subgenus Microsaurus ) lacks spines on the anterior margin of the pronotum, consistent with Q. mesomelinus and Q. brevicornis in Microsaurus and Q. fuliginosus in Quedius sensu stricto Stephens, whereas other the other species discussed (in the subgenera Raphirus Smetana and Quedionuchus Sharp ) do have spines, a character state which Staniec (1999, 2003) employs in his keys to the known pupae of Polish Staphylinidae .

Observations

Arthropods found to be present in the porcupine dung samples were: Sciaridae (Diptera) larvae and emergent adults (abundant); Trichocera maculipennis Meigen ( Diptera : Trichoceridae ) larvae (frequent); Psychodidae (Diptera) adults (occasional); Protaphorura armata ( Collembola: Onychiuridae ) and Folsomia sp. ( Collembola: Isotomidae ), as well as Parasitidae and other Acari, and Acrotrichis castanea (Mathews) adults ( Coleoptera : Ptiliidae ) (abundant). A second instar Meta ovalis (Gertsch) spiderling was also recorded. Undetermined Enchytraeidae (Annelida) worms were present.

Twenty­four hours after establishing the cultures, larvae were observed to have excavated cavities within the dung. Most of these cavities were next to the clear walls of the rearing jars, fortuitously making it possible to directly observe the growing larvae. The excavated “cells” were smooth­surfaced and somewhat irregular in shape, often eggshaped or sub­triangular, 0.6–0.8cm x 1.0– 1.5cm in dimension. Once created, the larvae were never observed to leave their cells, remaining in them in a semi­curled “C” or “J” position through to pupation: the adults left the cells shortly after eclosion.

The cultures were established on 5 October 1997. Almost all of the larvae in the samples were similar in size. The first pupa was observed on 27 October 1997 and with one exception all other individuals had entered pupation within the following three days: a single individual had not pupated until a month later, 29 November 1997. The first emergent adult was seen on 26 November 1997, several more had emerged by the 30 November 1997. Emergent adults were present a little earlier, on 19 November 1997, at the Frenchman’s II collecting site.

Figures

FIGURES 1–3. Quedius spelaeus spelaeus pupa. 1, lateral view; 2, dorsal view; 3, ventral view.