Plochionus pallens ( Fabricius, 1775 )

Garner, Beulah H. & Hancock, E. Geoffrey, 2018, The ‘ Lost’ Types of Carabus Pallens Fabricius, 1775 (Coleoptera: Carabidae: Lebiinae) from the Banks and Hunter Collections: Lectotype Designation, Redescription, and Distribution, The Coleopterists Bulletin 72 (4), pp. 845-857 : 846-851

Plochionus pallens ( Fabricius, 1775) ( Figs. 1–4 )

The synonymy below is modified from Bousquet

(2012).

Carabus pallens Fabricius 1775: 244 . Type locality: Dresdae [ Germany] (original citation).

Lebia bonfilsii Audinet-Serville 1821: 11 . Type locality: Bordeaux [ France] (original citation). Syntype (s) probably lost. Synonymy established by Chevrolat (1863: 189). Bousquet (2012) noted “LeConte’ s collection holds a specimen labeled P. Bonfilsii Dej. type! [handwritten] / pallens 2 [handwritten]”. This specimen’ s pin compared with examples of Dejean’ s specimens’ pins, assuming original pins remain, are not the same. Chevrolat’ s collection housed in the OUMNH was investigated for possible Audinet-Serville syntype (s). No suitable specimen was found.

Plochionus boisduvali Gory 1833: 198 . Type locality: Senegal [Africa] (original citation). Synonymy established by Chaudoir (1872: 168).

Plochionus valens LeConte 1863c: 5 . Type locality: Pennsylvania [USA]; Tampico [ Mexico]; (original citation), restricted to Penns [ylvania] by Lindroth (1969: 1066). Two syntypes in MCZ [# 5823]. Synonymy established, under the name Plochionus bonfilsi (Audinet-Serville) , by LeConte (1880a: 86).

Material Examined. See Appendix 1.

Original Description. Fabricius (1775): “ pallens . 47. C. pallidus , elytris striatis. Habitat Dresdae. Statura et magnitude C. vulgaris. Elytra striata.”

Redescription. Lectotype Female. Adult body surface, legs, and antennae rufo-testaceous; Pronotum transverse to quadrate; deeply explanate laterally; sides arcuate, tapering more profoundly in apical third ( Figs. 1–2 ). Elytral intervals convex, striate interneurs fine, elytra shiny. Head: Clypeus truncate, only slightly broader at base, bearing large setal pore at lateral margin; clypeus rather indistinguishable from labrum; labrum narrower than clypeus; truncate at apex with angles rounded, slightly narrowed to the base; bearing 6 evenly spaced robust apical setae; frons clearly demarcated from clypeus; frons with faint transverse rugosity and small, parallel, transverse carina beginning at the apical orbital setal pore; excavated at oblique angle to base of clypeus. Antennomeres moniliform; scape nearly as long as antennomeres 2 and 3; antennomeres 5–11 almost parallel-sided; dorsoventrally depressed; almost quadrate. Mentum deeply excavated; mentum tooth triangular, epilobes distinct. Mandibles arcuate laterally; stout; terebra markedly pointed; no visible notch; series of dorsal, fine parallel notches from widest part of the mandible to the terebra. Maxillary palpi slender. Labial palpi multi-setiferous; apical palpomere obliquely truncate; flavous at tip. Prothorax: Pronotum transverse-quadrate, more or less as wide as long, broadest at position of lateral setae before tapering anteriorly; median longitudinal line deep; pronotal sides arcuate, tapering more profoundly in apical third; basal angles produced, obtuse, base only sinuate at middle, slightly reflexed at hind angle; lateral margins broadly explanate, deeply depressed at hind angles; lateral margin effaced; base with faint bead; transverse crenulation on disk of pronotum. Pterothorax: Oblong, wider than pronotum; humeri angled, only slightly rounded; sides slightly arcuate medially, explanate sides broadest at middle. Elytral intervals convex; 2 setiferous pores placed apically and basally on interneur 3; elytra explanate on lateral margin; elytral microsculpture isodiametric. Legs: Tarsomeres 1–4 densely pilose ventrally; terminal tarsomere glabrous with 2 rows of 3 equally spaced, setiferous pores; tarsomeres quadrate to triangulate; 4 th tarsomere deeply emarginated, not bilobed; finely impressed isodiametric microsculpture dorsally and ventrally; terminal tarsomere twice as long as tarsomere 4. Adhesive climbing setae: [Ventral view described from 4 th tarsomere of male paralectotype ( Fig. 5 ); terminology follows Stork 1980.] Two parallel rows of adhesive setae present on tarsomeres 1–4; shaft elongated and slightly folded inwards; plate dorso-ventrally flattened and extended laterally to form a triangular shape; no obvious distinction between plate and shaft (squamo-setae); surface sculpture of distal plate with dense and fine nodules; shaft flexible and slightly bending ventrally; rim along length of apex of distal plate. Abdomen: As in description for genus. Female genitalia: [Some characters were not retrievable on account of the age and condition of the specimen. Those characters clearly visible are described here.] Lateral tergite (lt) forming a 45° angle tapering acutely to tip, tuberculate patch along upper sclerotized arm of lt ( Fig. 4 ); reproductive tract with elongate, relatively broad and robust bursa copulatrix (bc); [common oviduct (co) retrieved in dissection but with no describable character]; gonocoxite 1 (gc1) broad, almost quadrate with irregularly placed short, robust setae dorsolaterally; base (b) only slightly broader than apex of gonocoxite 2; gonocoxite 2 (gc2) elongate, moderately recurved laterally, tapering to base with irregularly placed short, robust setae dorso-laterally; blade (bl) obliquely angled with ensiform setae at apex and finer brush-like setae forked at tip.

Male Genitalia. Dissected from specimen: [printed, black border] Perou // [printed, under] Bon vouloir / collection. // [printed] H.E. Andrewes Coll. / B.M. 1945-97. Compared with type. Parameres asymmetric, apices rounded, left paramere (lp) lobelike, 2X larger than spatula-like right paramere (rp); endophalus with densely spaced spicules and isodiametric microsculpture throughout; ostium (os) wide, acutely angled; phallobase robust, slightly humped towards sagittal crest (sc); phallus tapered, rounded at apex, furnished with dense, short setae, shaft with irregular and sparse, short, robust setae (s) ( Fig. 3 ) .

Dimensions. ABL = 5.3–8.1 mm.

Type Material. Lectotype female ( Fig. 1 ). Plochionus pallens ( Fabricius, 1775: 244) (= Carabus pallens Fabricius, 1775 ). Type locality: Dresdae [Dresden, Germany] (original citation). Label data: [printed] 141012 // [printed, black border] [handwritten] Car. pallens / Fabr. Pag 309 No 57 // [printed, red border] LECTOTYPE / [handwritten] Carabus / pallens / (Fab., 1775) / [printed] det. B.H. Garner 20 [handwritten] 17.

Paralectotype male ( Fig. 2 ). [printed, black bor- der] [handwritten] Carabus pallens / Fab. Entom. P.

r = rim, sh = shaft.

244.N. 47.// [printed, red border] PARALECTOTYPE / [handwritten] Carabus / pallens // (Fab., 1775) / [printed] Det. B.H. Garner 20 [handwritten] 17.

Etymology. The specific epithet, pallens , is a Latin present participle of the verb palleo meaning pale. Our proposed English vernacular name is pale tent-invader beetle.

Natural History. This species is macropterus. It has been observed flying to lights. It closely resembles Plochionus timidus Haldeman , although P. pallens is larger and the pronotum quadrate, whereas P. timidus has the ‘moon-shaped’ pronotum that differentiates it into the subgenus Menidius Chaudoir.

Plochionus pallens is a predatory species, so it is hypothesized that it is feeding on eggs or larvae of insects within stored products in which it has been found. Other species within the genus Plochionus exhibit strong association with lepidopteran pests, particularly those of stored products as well as tentforming lepidopterans (based on label data from 708 specimens [unpublished data]). As Duffey (1890) demonstrated, P. timidus feeds on the larvae of the tent-forming erebid lepidopteran Hyphantria cunea (Drury) , some species of Tortricidae , leaf-rolling moths, and Tineidae fungus-moth larvae. If it is assumed that members of Plochionus (sensu lato) are associated with web- or tent-forming caterpillars, then which of these prey types P. pallens might favor is unknown. Recorded stored products within which it is transported include gardenias, orchids, cactus, rice, dried banana, cocoa beans, garlic bulbs, sweet potato, green chili peppers, peanuts, nutmeg, and sour limes (data from label transcription of 128 specimens; see Appendix 1). Further investigation into the lepidopteran pests associated with these stored products would yield interesting data corroborating an association with tent-forming caterpillars.

Geographic Distribution. The type locality given by Fabricius is ‘ Dresdae’ meaning Dresden in Saxon Germany. Dresden lies in the Elbe Valley and is fed by the River Elbe that connects to the nearest maritime port of Hamburg on the north coast of Germany. Fabricius always traveled by boat from Hamburg to London and sent specimens and books by this route through his Hamburg friend Paul Dietrich Giseke (Dominik Huenniger, personal communication, 2016). The data from 128 label transcriptions from various European collections produced eight other records of P. pallens from Germany, five specifically from Hamburg. These specimens are from the collections of Edmund Reitter (1845–1920) and Arnošt Jedlička (1888–1968) (from HNHM and NMPC, respectively). Ballast from North America , as well as the commercial stored products, would be unloaded in Hamburg. There was extensive shipping traffic between North America and Hamburg throughout the 18 th and 19 th centuries, including, for example, immigrants to North America from Germany ( Jerchow 1984). Commodities such as sugar, coffee, and tobacco

arrived from the Americas and were distributed from the port of Hamburg to other European destinations ( Draper 2015).

The original natural distribution of P. pallens is difficult to establish as many specimens have been recorded as imports having been intercepted at or associated with ports and port localities. However, based on label data from 128 specimens, it is likely that the origin of the species is southern USA or Mexico ( Fig. 6 ).

Fabrician Specimens in the Collections of the Hunterian Museum, Glasgow and the Natural History Museum, London. The insect collection in Glasgow was laid out by William Hunter’ s Trustees who also listed the specimens in a manuscript catalogue. This was drawn up after his death (1783) as a preliminary to the bequest being transferred to

the University of Glasgow. The arrangement and names used on the cabinet labels and in the catalogue correspond to Fabricius (1781), being the most up-to-date work available to them. Individual specimen labels in Fabricius’ s handwriting are rare, even though he was the curator engaged by Hunter to manage his natural history collections, so the cabinet labels are the main means of tracking them. Fortunately, the great majority of the original drawers (see Fig. 9 ) retain the exact order in which they were listed, so it is known the collection has remained as it was laid out at the time. Each cabinet label with the species name bears the page and species number from Fabricius (1781) as in Fig. 10 . One specimen of P. pallens is given in the Trustee’ s list, and it is still present in the drawer in the expected position. The Trustees were not entomologists and would have relied on existing information supplied in some form by Fabricius in order to assign the names. His most recent visit to London had been in the summer of 1782.

The role of Fabricius in curating Hunter’ s collection and adding to it from duplicates or bequests from other collectors and their cabinets is detailed by Hancock (2015). Research by Staig (1940) and Staines (2002), for example, investigated the Coleoptera in Glasgow, but these are partial studies. A great deal of further work is needed to reveal all the types in this and the other orders of insects. This paper reveals the hitherto unsuspected survival of specimens of probable types in the case of P. pallens . Despite extensive archive and literature searches, no documentation has been found as to which or how many specimens Fabricius had at hand when he described P. pallens . His published species descriptions did not specify such data beyond a generally broad geographical range with occasional indication of habitat. The Joseph Banks collection of insects also retains few truly original data labels, but there are also many cabinet labels that give the page and species notation from Fabricius (1775) similar in style to those at HMUG ( Fig. 7 ). Despite her exhaustive research, Zimsen (1964) was not able to identify any collections containing putative type(s) of C. pallens . Drawers housing the lectotype and paralectotype of C. pallens are shown in Figs. 8 and 9 . The NHMUK Banks collection was moved from its original drawers sometime in the 19 th century, and no record has been found that recounts any detail. The HMUG collection, as described above, retains its original arrangement, which remains unaltered after recent transfer to modern storage units ( Fig. 10 ).

Figures

Figs. 1–2. Carabus pallens. 1) Lectotype in HMUG; 2) Paralectotype in NHMUK.

Figs. 3–4. Plochionus pallens. 3) Male aedeagus, dorsal, left, and right lateral aspects – lp = left paramere, os = ostium, rp = right paramere, s = setae, sc = sagittal crest; 4) Female reproductive system, dorsal aspect – b = base of gonocoxite, bc = bursa copulatrix, bl = blade of gonocoxite, co = common oviduct, des = dorsal ensiform seta, gc1 and gc2 = gonocoxite 1 and 2, lt = laterotergite.

Fig. 5. Plochionus pallens, ventral view of adhesive setae of male paralectotype. dp = distal plate, n = nodule,

Fig. 6. Distribution map of Plochionus pallens based on 128 label transcriptions.

Fig. 9. Original Hunter collection Coleoptera drawer.

Fig. 10. Carabus pallens re-housed into modern storage unit tray retaining arrangement exactly as original in HMUG.

Fig. 7. Cabinet label for Carabus pallens in the Banks collection.

Fig. 8. Original Banks collection Coleoptera drawer.