A taxonomic study on the genus Harpapion Voss, 1966 from China (Coleoptera, Apionidae)

Abstract Harpapion safranum sp. n. and Harpapion borisi sp. n. are described and figured. Harpapion vietnamense (Korotyaev, 1987) is recorded as new for China. The genitalia andterminalia of H. considerandum, H. coelebs andH. vietnamense are redescribed and redrawn. The diagnostic characters of Harpapion are defined. A key to the known species of the genus Harpapion from China is provided. Affinities with the genus Flavopodapion Korotyaev, 1987 are discussed.


Introduction
The apionid genus Harpapion was erected and initially placed as a subgenus of Apiotherium Beguin-Billecocq, 1905by Voss (1966, and it was later treated as a genus of Apioninae incertae sedis by Alonso-Zarazaga and Lyal (1999). Recently, it was considered a member of the tribe Aspidapiini Alonso-Zarazaga, 1990 based on its elongate-triangular scutellum and the genitalia with apparently primitive traits (Alonso-Zarazaga 2011). Moreover, it was recognized as an Afrotropical and Arabian genus (Alonso-Zarazaga and Lyal 1999) until two species, H. coelebs (Korotyaev, 1987) and H. vietnamense (Korotyaev, 1985), respectively from China and Vietnam were identified as new records of Harpapion in Southeast Asia . Wanat (1990) redescribed and figured in detail the Eritrean species H. dongollanum (Wagner, 1910), and then Alonso-Zarazaga et al. (2011) pointed out the diagnostic characters of Harpapion compared with Pseudaspidapion Wanat, 1990.
Recently, we obtained two more specimens of the monotypic species H. vietnamense, as well as two series of specimens which are considered to be two new species of the genus Harpapion from South China. In describing the new species below, we have also documented and figured the genitalia of H. considerandum (type species of Harpapion), H. coelebs and H. vietnamense.

Materials and methods
Materials examined of the new species for this study are to be deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing (IZCAS) and the Biological Museum, Sun Yat-Sen University, Guangdong (BMSYU). Type and identified specimens were obtained from BMSYU, Natural History Museum (NHM), Zoological Institute (ZIN) on loan or belong to IZCAS.
Descriptions were made and photographs were taken with a Canon EOS 5D mounted on a Nikon SMZ1500. Extended focus images were generated with CombineZM and edited with Adobe Photoshop CS 5.0 when required. Microscopic slides were studied under a Leica DM 2500 microscope and photos were taken with a Nikon CoolPix P7100. Drawings were made from the original photographs by using the software Adobe Illustrator CS5.0, or directly by using a drawing tube attached to the microscope.
Scanning Electron Microscope (SEM) photos were taken with a FEI ESEM Quanta 450 device and the software xT microscope control. Specimens were cleaned by hair pencil and mounted on the mounting card directly.
The dissecting method used follows Alonso-Zarazaga (1990). Abdomens were put into 10% NaOH for several hours until the inner tissues were digested, and the resultant structures were placed on a temporary microscope slide for examination.
After description, the genitalia and other parts of each specimen were placed in DMHF on an acetate card for long term conservation (Steedman 1958;Bameul 1990).
Labels are described as they are (in Chinese or Cyrillic), with pinyin romanization for Chinese and ISO 9:1995 for Russian, and translations in square brackets; labels are separated by semicolons and lines by slashes. Alternative modern pinyin romanizations are also given in some cases where labels are written using other romanization systems, like Wade-Giles.

Taxonomic treatment
Harpapion Voss, 1966 According to species examined, the diagnostic characters of Harpapion could be defined as follows: 1) scutellum triangular, distinctly elongate and basally projecting, apically raised ( Figure 13); 2) the meso-and metatibial mucros are evidently elongate and bent at their apices (rather than short and straight in Pseudaspidapion) (Figures 14, 16); 3) the rostrum is clearly dilated at the antennal insertion and distinctly constricted apicad in dorsal view; 4) the setae fringing the front margin of pronotum are parallel to it; 5) the scales are broad, especially on the meso-and metarostrum, head and propleuron, etc. 6) the 1 st elytral stria at base reaches the middle level of the scutellum; 7) the pygidium is of the aspidapionine type, subsemicircular in dorsal view, with the apical flange strongly raised, the transverse sulcus deep but not cutting the sides; 8) the ninth sternite (spiculum gastrale) is Y-shaped, slender and subsymmetrical, not winged; 9) the apex of the penis is moderately to distinctly curved in lateral view, sometimes the pedon is recurved at apex; 10) the tegminal plate is articulated with the free ring, laterally developed, enveloping; the parameroid lobes present a usually well developed apical membranous area with a small apical notch, the basal sclerotized area has a medial sinuation in its front margin and bears 4-7 macrochaetae on each side; the fenestrae are present and variable; the prostegium is bidentate with two lateral projections (absent in H. coelebs).
Harpapion vietnamense (Korotyaev, 1987 Genitalia and terminalia. Eighth sternite moderately elongate, apical edge constricted, relatively concave, basal edge with a medial tubercle, sides distinctly extended backwards ( Figure 39). Ninth sternite (spiculum gastrale) Y-shaped, symmetrical, not winged, manubrium about 2.25× as long as arms ( Figure 40). Penis in dorsal view with pedon sides almost parallel, apically elongate and distinctly constricted halfway, with 2 subdentiform projections, tectum evidently dilated apicad, in lateral view, pedon slightly depressed, apical plate distinctly elongate and gently curved ventrad, extreme apex recurved; temones about 0.74× as long as pedon; endophallus in anterior half with dense spicules and basal half with 2 sclerotized semicylindrical, hollow structures fused at base . Tegminal plate articulated with free ring, about 0.94× as long as manubrium, moderately depressed, slightly enveloping laterally; apical membranous area of parameroid lobes developed and extremely tapering apicad, with a minute apical notch, without distinctly visible microchaetae; basal sclerotized area slightly elongated, front margin widely and roundly sinuate, with 5-6 long macrochaetae and 8-10 sensilla on   (Korotyaev, 1987)  Vestiture composed of distinctly whitish, thick, lanceolate scales with acute to rounded apices, rarely truncate (some scales on hind margin of eyes elliptical to nearly rhombic) and grayish acute hairs on antennae, tibiae and tarsomeres. Pronotal vestiture centripetal, scales on apex parallel to margin, but on base perpendicular to margin, pronotal disc with scales distinctly longer and thicker than on legs, reaching base of anterior scales. Elytral scales in one row per interstriae, two irregular rows on disc, scales on striae 1/2-2/3 as long as scales on interstriae. One specialized seta on apical region of 9 th interstria.
Rostrum cylindrical and moderately robust, in dorsal view 8.25× as long as apical width, 1.45× as long as pronotum in midline, widest at mesorostrum, prorostrum constricted apicad, metarostrum with sides almost parallel, metarostrum with median dorsal area impunctate, dorsal submedial sulci and dorsal submedial keels weak, minutely punctate and pubescent, lateral area of metarostrum and prorostrum with weak oblong confluent punctures, weakly microreticulate, apical third of prorostrum almost impunctate, smooth and shining; in lateral view moderately curved, sides converging to apex, carinae and sulci weak, ventral medial keel fine and complete, ventral sublateral keels with dense line of scales under mesorostrum.
Head transverse, frons very weakly convex, as wide as metarostrum, constricted behind eyes, medial area impunctate and glabrous, lateral areas with irregular rows of punctures and scales, subocular keel not reaching middle of eyes, area between subocular keel flat, microreticulate and impunctate. Eyes round, moderately convex.
Scutellum elongate, triangular, ca. 2.00× as long as wide, 2 basal tubercles fused at base in front view, apical tubercle rounded, slightly prominent and hardly visible in lateral view (Figure 13).
Genitalia and terminalia. Eighth sternite moderately elongate, constricted to narrow, truncate apical margin, basal margin with sides distinctly extended backward ( Figure 51). Ninth sternite (spiculum gastrale) Y-shaped, not winged, manubrium ca. 3.00× as long as arms ( Figure 52). Penis in dorsal view with pedon slightly widened at level of ostium, distinctly constricted apicad, apical plate ogival, apex with button-like prong, tectum with sides almost parallel, apically moderately constricted, in lateral view, pedon depressed, moderately curved, apical plate slightly incurved; temones about 0.50× as long as aedeagal tube; endophallus without obvious structures (Figures 47-48). Tegminal plate articulated with free ring, laterally enveloping,; apical membranous area of parameroid lobes undeveloped, only laterally visible, without microchaetae; basal sclerotized area extremely enlarged and extended apicad, triangular-shaped, with 5 short macrochaetae on each lateroapical edge, without sensilla; fenestrae short, transverse, narrowly separated; linea arquata present, very close to basal margin of fenestrae; prostegium bidentate, teeth acute, slightly curved; median unsclerotized strip elongate and surpassing fenestrae. Manubrial apex evidently and asymmetrically broadened (Figures 45-46 Remarks. Harpapion safranum sp. n., can be easily recognized from other species from China by its external characters (red colour of entire legs and antennae, etc.) However, it is extremely similar to H. considerandum which can be distinguished from the former by genitalia which were described above and illustrated in Figures 1-7.
Etymology. This species is named safranum after its testaceous legs. This is a Medieval Latin name of the plant now called Crocus sativus L. (saffron) which yields a yellowish-orange dye. It is considered a noun in apposition. Integument generally piceous, tibiae and tarsi relatively paler and antennae pale reddish brown (Figures 53-54).

Harpapion borisi
Vestiture composed of whitish to semitransparent, partly thick, lanceolate scales with acute to rounded apices, and semi-transparent acute hairs on antennae, tibiae and tarsomeres. Head, meta-and mesorostrum bearing broader scales with rounded apices, prorostrum nearly glabrous. Pronotal vestiture centripetal, scales on apex parallel to margin, on base perpendicular to margin, pronotal sides with scales distinctly longer and thicker than those on disc and elytra, reaching base of anterior scales. Elytral scales in one regular row per interstria, scales on striae tiny, grayish to transparent. One specialized seta on apical region of 9 th interstria.
Rostrum cylindrical and moderately robust, in dorsal view 5.71× as long as apical width, 1.22× as long as pronotum in midline, widest at mesorostrum, prorostrum tapering apicad, tube-shaped, metarostrum slightly constricted at rostral base, metarostrum with no distinct sulci, two very shallow and parallel punctate dorsal submedial sulci expanded from mesorostral level to nearly middle of prorostrum, meso-and metarostrum surface microreticulate, matte, prorostrum smooth, shining, almost impunctate; in lateral view weakly curved, almost straight, sides converging to apex, each side with very thin low dorsal sublateral keel running from front margin of eye to upper margin of scrobe and beyond, limiting ventrally dorsal sublateral sulcus.
Head almost as long as wide, frons very weakly convex and slightly narrower than metarostrum, constricted behind eyes, medial area rough, wrinkled, subocular keels curving to meet medially, nearly reaching middle of eyes, area between subocular keel flat, microreticulate and impunctate. Eyes subcircular, distinctly convex.
Scutellum large, elongate, triangular, ca. 2.5× as long as wide, with two separate basal tubercles, obtuse; apex constricted and slightly raised, moderately visible in lateral view.
Etymology. This species is named after the Russian curculionidologist Boris A. Korotyaev, who has much improved the taxonomy of Apionidae from South China and helped us in many ways.

Discussion
Some previously considered generic characters of the tegmen like parameroid lobes, fenestrae and prostegium (Alonso-Zarazaga 1983 show a great amount of variation among the above species. The basal sclerotized area (the dorsal layer of the tegmen (Wanat 2001)) of parameroid lobes of the type species H. considerandum is short and medially sinuate, and the apical membranous area (the ventral layer of the tegmen (Wanat 2001)) is well developed and prominent. These characters are also present in H. vietnamense, H. coelebs and H. borisi but not in H. safranum which externally resembles H. considerandum very much. Also the fenestrae of H. considerandum join medially, as in H. vietnamense, but they are separated in the other species as well as in H. dongollanum. Particularly, the prostegium of H. coelebs is extremely retracted and lacks the lateral teeth, which is unique hitherto in this genus. After all, significant similarities of external characters as well as most internal characters let us conclude that they should remain for the time being in Harpapion, and the inconsistency mentioned above has to be considered as a specific divergence not having generic value. Additionally, a close genus, Flavopodapion Korotyaev, 1987(type species F. gilvipes (Gemminger, 1871) (Alonso-Zarazaga et al. 2011) resembles Harpapion very much. On one hand, its scutellum seems normally triangular, but two slightly raised basal projections can be found under SEM (Figure 12). On the other hand, its mesoand metatibial mucros show the peculiar bending present in the species of Harpapion ( Figure 15). Other characters such as the rostrum clearly dilated at antennal insertion, the scale arrangement on the anterior and posterior margins of the pronotum and the apical flange of the pygidium strongly raised, etc. (Figures 8-11) coincide with those of Harpapion. However, some characters underline the differences between both genera, namely, in Flavopodapion, the relatively slender body, the triangular scutellum not constricted in the apical half and lacking a raised apex and clear basal projections. Moreover, the genitalia and terminalia show more significant differences: the ninth sternite (spiculum gastrale) with the manubrium distinctly shorter than the arms (Figure 24), the parameroid lobes with the basal sclerotized area evidently elongate, laterally extending apicad and leaving a membranous asetose area extending between the lobes and not tapering apicad, so that the apex in a general outline seems truncate, not pointed, the widely separate, reduced, lateral fenestrae, almost round in dorsal view, and the obsolete median unsclerotized strip (Figures 17-18). However, not too many related species are known in detail to allow drawing definite conclusions on the systematics of this particularly complex group of Apionidae.