Bothinodroctonus longicornis Knížek and Mandelshtam, 2015

Knížek, Miloš & Mandelshtam, Michail, 2015, Description of a new species of Bothinodroctonus Schedl, 1969 (Coleoptera: Curculionidae, Scolytinae) from Africa, Zootaxa 3964 (2), pp. 288-293 : 289-291

Bothinodroctonus longicornis Knížek and Mandelshtam , sp. nov.

Figs 1–6

Type material. Holotype male, pinned, with labels as follows: 1st label “ GAMBIA, TENDEBA CAMP, AT LIGHT, IN SEMI ARID VEG., NEAR RIVER GAMBIA; 18.30–20.30. 14.XI.1977; UTM 28POK1285. LOC. 12A”; 2nd label “ LUND UNIV. SYST. DEPT.; SWEDEN-GAMBIA/ SENEGAL; NOV. 1977 —CEDERHOLM- DANIELSSON-HAMMARSTEDT-HEDQUIST-SAMUELSSON”. Paratypes: pinned, with labels as follows: 2 males, the same data as the holotype; 1 male, KENYA C. S.; Mwingi, Nguni; 7.IV. 2004; M. Snížek lgt.”.

Holotype and one paratype deposited in the collection of Zoological Museum of Lund University ( ZMLU), 1 paratype in Zoological Institute of Russian Academy of Sciences (St. Petersburg), 1 paratype in coll. of M. Knížek (Praha).

Diagnosis. Body shape of general characteristics of the genus ( Schedl 1969), which resembles more closely species of the genus Carphoborus instead of Polygraphus . Body stout, cylindrical, covered with scales, frons of the male deeply concave (in original description of the genus the sexes were reversed by Schedl (1969)), eyes triangularly emarginated (Schedl erroneously described eyes as stout oval), antennal club conical, slightly flattened, marked by three rows of setae, pointed apically, antennal funicle 6-segmented (see note on other species of Bothinodroctonus later in this paper), second interstriae slightly depressed in elytral declivity. Bothinodroctonus longicornis differs mainly by the presence of a prominent pair of frontal hornlike processes, and the absence of upwardly-directed mandibular processes and of a peculiar extension of the vertex shared by the other species of the genus (except only female of B. setosus is known).

Description. Length 1.7–1.8 mm (1.8 mm in holotype), 2.3–2.4 times longer than wide (2.4 in holotype). Colour brown to dark brown. Head. Frons strongly excavated, concave, concavity extending from epistomal margin to vertex and throughout the whole width between the eyes, lateral margins acutely elevated, upper margin strongly acutely elevated, slightly protruded in the middle, concavity more or less regularly rounded, with shallow parallel depressions separated by a raised central longitudinal broad elevation. Surface of the concavity smooth, finely shagreened and very densely finely punctate, semi-shining. Lower lateral edges just above the epistoma bearing very long upward directed slender horn-like processes; their length ranging from nearly reaching the upper elevated margin of frontal concavity to exceeding this margin by one fifth of their length. Processes parallel or slightly convergent in some specimens, slightly flattened antero-posteriorly, antero-internal margins ornamented by series of small tubercles of which one or two tubercles (differs in particular specimens) positioned on the second fourth of the process length are more prominent, other tubercles forming an undulation becoming finer towards apex, apex of the processes round, not pointed. Mandibles without any processes. Vertex shining, finely rugose in concentric circles in the middle, rugosities becoming more longitudinal laterally. Eyes relatively large, displaced latero-ventrally due to the frontal excavation, sharply triangularly emarginated on anterior margin in upper half. Vestiture of frons restricted to the margins of the excavation and to the horn-like processes only, consisting of sparse short scale-like setae. Antennae light brown, antennal funicle 6-segmented, antennal club longitudinally conical, slightly flattened antero-posteriorly, very narrowly rounded (nearly pointed) apically, with three transverse straight rows marked by setae. Pronotum. Wider than long, 0.7 times as long as wide, widest in the middle of its length, very weakly if at all declivous in front from lateral view, posterior margin round, not ornamented, straight transversally, lateral margins parallel in posterior half, constricted anteriorly, anterior and posterior margins not armed, anterior margin rounded; whole surface punctato-granulate, granules fine, punctuation rather strong and deep, semi-shining; vestiture of sparse short and wide (round or nearly round—differs between the specimens) scale-like setae positioned in punctures (these setae often abraded), setae more closely set in the middle of pronotal posterior margin. Elytra. 1.5–1.7 times as long as wide (1.7 in holotype), 2.1–2.5 times longer than pronotum (2.5 in holotype), as wide as pronotum, parallel on basal three-fourths, then converging to rounded apex; scutellum not visible; basal margin slightly procurved, armed by conspicuous crenulations—row of tubercles directed upward, submarginal crenulations occurs in the space of three or four first interstriae; striate, strial punctures dense and coarse, distance between the punctures up to half of their diameter; interstriae slightly narrower than striae, slightly elevated and rounded, subgranulate, granulation becoming stronger posteriorly and on elytral declivity; vestiture of conspicuous, short and broad (round or nearly round—differs between the specimens) scale like setae positioned mostly uniseriately on basal half of elytra, becoming biseriate in posterior half and on elytral declivity; elytral declivity rounded from lateral view, bisulcate due to the shallowly depressed second interstriae, depressions smooth, shining, deeply punctate in rows, slightly narrowed apically, but not reaching the elytral apex, elytral apex rounded, all interstriae except the second with conspicuous uniseriate tubercles, these tubercles slightly smaller and biseriate on the third interstriae. Legs. Brown, femurs slightly darker. Procoxae contiguous, mesocoxae separated more widely than the width of scapus, metacoxae separated slightly more than mesocoxae. Pro-, meso- and metatibiae slender, on outer lateral margin with 3 socketed teeth displaced apically, lateral margin with numerous longitudinal scale-like setae, other surface with sparse hair-like setae of nearly double length compared to the scale-like setae. Aedeagus ( Fig. 6 ). Dissimilar to aedeagi of Polygraphus species common in Europe ( P. poligraphus (Linnaeus, 1758) , P. punctifrons Thomson, 1886 and P. subopacus Thomson, 1871 ) ( Chilahsaeva, 2010) and can be distinguished by much longer apophyses, by presence of long and bent ejaculatory duct, by circular tegmen and by absence of supporting basal structures in the aedeagus body. Compared to Carphoborus perrisi (Chapuis, 1869) , aedeagus of Bothinodroctonus longicornis is twice as long, much strongly chitinized and also with distinct chitinized ejaculatory duct that is invisible in C. perrisi . It seems, then, that the newly described species (and maybe the whole genus) is not very similar to either Polygraphus and Carphoborus ; note, though, that Polygraphini as currently conceived is quite possibly polyphyletic, and Carphoborus does not seem to belong to this grouping of genera ( Jordal 2009).

Etymology. Name of this new species is derived from the morphology of its frons bearing two very long horns, stylus-like processes: Latin “ longus ”, long, and “ cornu ”, horn.

Biology. Nothing is known about the biology of the species. Wood (1986) categorized the genus as phloeophagous.

Distribution. Afrotropical region, Gambia, near Gambia River, and Kenya, Mwingi, Nguni. Even though the two localities are distant (west and east tropical Africa), the studied specimens are most likely of the same species.

Note on other Bothinodroctonus species. Available specimens of Bothinodroctonus bicinctus Schedl were studied carefully during the study—three paratypes of the species from Schedl’s collection deposited in Museum of Natural history Vienna and additional three specimens of the species in collection of Miloš Knížek. Additionally, both species described by Wood (1988), B. indicus and B. setosus and deposited in the National Museum of Natural History, Washington, were studied with help of Sarah Smith and Anthony Cognato (Michigan State University). Questionable information from the literature was studied, especially the number of antennomers of antennal funicle and existence of septum in antennal club. Wood (1986) ranged the whole genus in between the species with 5- segmented antennal funicle, without any other comments, while he didn't mentioned nothing on that in the description of B. indicus and B. setosus ( Wood 1988) . In all studied specimens of B. bicinctus (both sex) the antennal funicle is 6-segmented ( Fig. 7 ), also in B. setosus the antennal funicle is 6-segmented, while the antennal funicle of B. indicus is 5-segmented (S. Smith and A. Cognato—personal communication). “Three circular rows of densely placed short setae on antennal club” ( Schedl 1969) were confirmed in B. bicinctus , but only on anterior side of the club, the first and second rows are slightly, and strongly respectively, procurved on the posterior side, the second touching the third row on that side. Existence of a septum in antennal club in B. bicinctus , as mentioned by Schedl (1969), was not confirmed on the Schedl’s slide preparation ( Fig. 7 ). According our opinion the darker spots on the antennal club are simply caused by “shadows” or thickness of the particular antennal club segments (suturae) (note: the antenna in the Schedl’s slide preparation is broken in several places due to the mounting process– Fig. 8 ).

The new locations for B. bicinctus are: Indonesia (Sumatra): Riau, and Malaysia: Pahang (M. Knížek coll.).

Figures

FIGURES 1 – 6. Bothinodroctonus longicornis Knížek and Mandelshtam, sp. nov. 1, dorsal view; 2, lateral view; 3, elytral declivity dorsal view; 4, elytral declivity; 5, frons; 6, aedeagus.

FIGURES 7 – 8. Bothinodroctonus bicinctus. 7, antenna—anterior side; 8, detail of antennal club.