Pachycerus sellatus, FAUST, 1904

Meregalli, Massimo, 2009, Revision of the Indo-African Pachycerus Schoenherr, 1823, with a description of four new species (Coleoptera: Curculionidae: Lixinae), Zoological Journal of the Linnean Society 157 (2), pp. 295-325 : 303-306

PACHYCERUS SELLATUS FAUST, 1904

Pachycerus sellatus Faust, 1904: 223 .

Cleonus (Pachycerus) Schenklingi Csiki, 1934: 53 .

Lectotype male (designated here): 1. Square blank gold label; 2. ♂ Bengal, Baden (Faust’s hw); 3. sellatus Faust (Faust’s hw); 4. ex. coll. Faust (hw, yellow); 5. Type (pr, red); 6. Staatl. Museum für Tierkunde

Dresden (pr); 7. Pachycerus sellatus Faust, 1904 , Lectotypus, 2007 Meregalli des. (red, pr) (SMTD).

Paralectotype female (designated here): 1. F. (small, hw); 2. sellatus Type (hw), det Faust (pr); 3. sellatus Fst (hw); 4. sellatus Fst, Ind. or. (pr); 5. Pachycerus sellatus Faust, 1904 , Paralectotypus, 2007 Meregalli des. (red, pr) (NMW).

Other specimens: India: ‘S. India, Salem [11°39′N, 78°09′E], 30-VIII-1934, P.S. Nathan’, 7 ex. (6 BMNH, 1 MER); ‘S . India, Mysore State, Shimoga [13°55′N, 75°34′E], 1865 ft., 6.V.1937 ’, 2 exx. ( BMNH) ; ‘S. India, Mysore State, Shimoga , 1865 ft., 7.V.1937 ’, 1 ex. ( BMNH) ; ‘ N. India’ 1 ex. ( BMNH) ; Pakistan: ‘ India, Punjab, Murree Hills [33°54′N, 73°23′E], Thobba’, 1 ex. ( BMNH) ; ‘ West Pakistan, Rawalpindi Umg., Basal, 4-7.I.[19]56, Kalachitta Range, Chr. Lindemann leg.’, 1 ♂ ( NHMB, coll. Frey) ; Burma: ‘ Burma, Magwe pr., Seikpyu [20°53′N, 94°47′E], 100 m, 25- 26.02.1996, leg. S. Kasantsev’, 1 ♀ ( MER) ; Nepal: ‘ Nepal: Kosi #5, Mangmaya 27°07′N, 87°15′E to Akibunkyabeshi 27°12′N, 87°15′E, 300–400 m, 30.V.[20] 01/NHMB Basel, expedition to Nepal 2001’ 1 ♀ ( NHMB) .

Type: In Faust’s collection (SMTD), one specimen is preserved, designated here as the lectotype. A syntype is preserved at the NMW, which is designated here as the paralectotype. Csiki (1934) considered all Cleonini in the single genus Cleonus Schoenherr, 1826 , and replaced the epithet sellatus with schenklingi to avoid junior secondary homonymy with Cleonus sellatus (Faust, 1894) (= Chromonotus menetriesi Faust, 1894 ). However, Csiki’s substitute name was never used, and thus the junior secondary homonym is not to be rejected (Art. 59.3 ICZN).

Measurements: Body length excluding rostrum: 7.34 mm. Rostrum: length, 1.54 mm; width, 1.03 mm; ratio, 1.49. Pronotum: length, 2.12 mm; width, 2.69 mm; ratio, 0.79. Elytra: length, 6.13 mm; width, 4.07 mm; ratio, 1.50. Ratio of elytral to pronotal length: 2.89 (♀; Salem).

Redescription ( Figs 29–42 ): Body oval, integument glossy, black, including legs; antennae very dark reddish, nearly black; vestiture with bifid scales and distinct setae ( Figs 29–30 ). Rostrum stout, strong, subquadrate in transverse section, dorsolateral margins broadly and obtusely keeled, high, parallel, raised up to apex, minutely punctulate, and with some large round punctures; central keel high, more or less distinctly broadened from base to antennal insertion, with a deep median furrow from middle of length to antennal insertion; dorsum with deep furrows delimited by the broad longitudinal keels; apex densely and deeply wrinkled, epistoma smooth, convex at middle, prominent in centre; in lateral view rostrum straight, moderately thickened at apex; upper margin of scrobes not keeled, smooth, weakly curved, directed to and nearly touching the lower apex of eyes; lower margin of scrobes subparallel with upper margin, curved downwards, short, reaching underside at base; scrobes deep, narrow; sides in front of eyes punctured. Vestiture relatively thick, composed of light-greyish bifid or simple scales, mainly inserted in the furrows, inward- or forward-directed here, and outward-directed at apex ( Figs 31, 32 ). Antennae relatively narrow, scaly; scape short, straight, moderately thickened from base; segment I of funicle subcylindrical, as long as wide, segments II–VII short, transverse; club elliptical, covered with fine and glossy hairs, shorter than funicle, segment I at base with scarcely evident, very narrow scaly ring ( Fig. 41 ). Head transverse, large, vertex flattened at centre, rough, and with some irregular punctures, raised laterally above eyes to a small conical hump; eyes large, elliptical, moderately convex on their upper part, lower margin rounded. Pronotum transverse, base scarcely curved, weakly prominent at middle towards scutellum, sides subparallel or barely widened from base to middle of length, then slightly bulging outwards, and regularly convergent at apex; apex feebly curved above head, postocular lobes distinct; disc with a broad, round, shallow impression, often formed by a smaller anterior and a larger posterior impression, separated by a median bulge, with dense irregular large punctures, median line not present, only slightly distinct near apex; dorsolateral part with less densely impressed round punctures, with interspaces nearly as large as punctures, and with fine secondary punctulation; sides with sparse punctures and one distinct glossy granule at the margin between dorsum and sides, in the middle; vestiture composed of light-greyish bifid scales, sparse on disc, quite dense on a lateral stripe, its lower margin straight, upper margin curved or angular, prominent towards disc; setae scarce, limited to lower part of pronotum sides ( Fig. 34 ). Scutellum: very small and nearly indistinct. Elytra oval, in lateral view elytra flattened, weakly and regularly curved, declivity feeble, barely distinct; at base as large as base of pronotum, distinctly widened at humeri, sides nearly rectilinear, regularly converging at apex, with small apical teeth scarcely distinct in front of interval 3; odd intervals weakly convex, higher and wider than even intervals, higher and broadened at base, surface smooth, lacking granules or wrinkles; even intervals narrow, nearly flat, irregularly delimited; striae broader than even intervals, composed of large, dense, round punctures, some of the interspaces of punctures forming short transverse ridges between neighbouring odd intervals; vestiture composed of yellowish bifid scales, connate at base ( Fig. 35 ), in part absent from base between intervals 4 and 9, completely absent from a broad median transverse subquadrate stripe between intervals 3 and 9, and from two round spots on declivity behind apex of interval 5, thus forming a relatively narrow transverse light sub-basal stripe, irregularly broadened on sides, and a more uniform vestiture behind middle of length; setae present, short, more visible in lateral view, more frequent and erect on declivity, usually settled in a single row on odd intervals. Legs relatively short, with simple elongate and acuminate scales, and long sparse setae; femora scarcely thickened at middle; fore tibiae short, straight, weakly broadened at apex, with a fringe of denticles; middle and hind tibiae shorter, weakly broadened from base to apex; tarsi short, segment I very short, conical, segment II transverse, segment III not longer than segment II, lobes very short, not widened; onychium as long as segments I–III of tarsi, claws strong, moderately divergent, connate up to middle of length; underside of tarsi without adhesive pad, replaced with a few scales and some spiny setae. Ventrite I as long as ventrite II, both longer than ventrites III–V combined; ventrite III and ventrite IV, each one quarter as the length of ventrite II, ventrite V slightly longer than ventrite IV, and transversely impressed near apex; vestiture composed of dense, slender, bifid scales, with six bare glossy round spots on ventrites I, eight on ventrite II, a central common spot between ventrites I and II, and six smaller and more irregular spots on ventrites III and IV; hair-like curved setae, more frequent and longer on ventrites IV and V ( Fig. 42 ). Aedeagus slender, median lobe tubular, weakly and regularly curved; apical lamella shortly triangular ( Figs 38–40 ); sternum VIII of female with short apodeme, arms broadened at middle, converging apicad, lamina nearly not sclerotized, sclerotization limited to apex of arms ( Fig. 33 ); spermatheca robust, with short and thick, moderately curved cornu, narrowed towards apex, nodulus shortly thickened ( Fig. 36 ). Hemisternites short, with angular apical constriction typical of the genus; styli short, apical ( Fig. 37 ).

Variation: The few specimens examined are very variable. The male from Pakistan is smaller, with a length of 5.63 mm, and its vestiture hides the sculpture of the integument over the whole body; the pronotum is less transverse, with ratio length/width of 0.85, and the elytra have more evident and dense raised setae; the specimen from the neighbouring locality of Rawalpindi is, however, not particularly differentiated from the Indian specimens: the female from Burma has a distinctly stronger sculpture, with deeply impressed punctures on the pronotum and the elytral striae, and has a distinctly prominent lateral hump on the middle of the sides of the pronotum; the specimens from southern India, Salem, are very similar to the type.

Affinities: At the southern limits of its range, P. sellatus is sympatric with P. barclayi sp. nov.: the differences between the two species are discussed after the description of the latter. The populations at the northern extremes of the range, in Pakistan, may be nearly sympatric with some Palaearctic taxa of Pachycerus , namely Pachycerus desertorum Faust, 1904 and Pachycerus obliquatus Faust, 1883 , which are diffused in the Central Asian steppes. These species lack the supraorbital tubercle on the head, have the rostrum nearly twice as long as wide, the pronotum with glossy granules on disc, lacking round isolate punctures, and have the elytral setae shorter than the scales.

Distribution ( Fig. 108 ): Pachycerus sellatus has a fairly broad range, from northern Pakistan to southern India, stretching east to Burma.

Figures

Figure 108. The Indo-African species of Pachycerus. Distribution map. Map taken from Encarta World Atlas 2000 (Microsoft Corporation), refined with Photoshop 7.0.

Figures 29–42. Pachycerus sellatus Faust, 1904, India, Salem, male: body (29, 30); rostrum (31, 32); antenna (41); pronotum (34); detail of elytral scales (37); ventrites (42); aedeagus (38–40). Pachycerus sellatus, Burma, female: sternite VIII (33); hemisternite (37); spermatheca (36). Scale bars: 29, 30, 5 mm; 42, 2 mm; 31, 32, 1 mm; 33, 34, 37, 39, 41, 0.5 mm; 36, 38, 0.2 mm.