One the genus Tocama Reitter (Coleoptera, Scarabaeidae, Melolonthinae), with descriptions of two new species from Indochina

Abstract Two new species of the Oriental scarab genus Tocama Reitter, 1902, Tocama laosensis sp. n. and Tocama procera sp. n., are described from Indochina with diagnoses, distributions, remarks and illustrations. A key to the species of the genus is provided with a checklist with several nomenclatural changes: Hoplosternus tonkinensis Moser, 1913 is transferred to Tocama; Hoplosternus pygidialis Moser, 1915 syn. n., Tocama atra atra Keith, 2006 syn. n. and Tocama atra reichenbachi Keith, 2007 syn. n. = Tocama tonkinensis (Moser).


Introduction
The Oriental genus Tocama Reitter, 1902 is a small scarab beetle group that includes seven species, two of which are newly described here. Species of Tocama are distributed in southeastern Asia, eastern and southern China, and Taiwan. Tocama species are 14.0-30.5 mm in length, castaneous to blackish brown beetles that are dorsally covered with dense, tiny, brownish grey or yellowish brown, scale-like setae. The genus Tocama was first proposed by Reitter (1902) based on a single species, Melolontha rubiginosa Fairmaire, 1889, as a subgenus of the genus Melolontha Fabricius, 1775. In his paper, however, Reitter merely described the color of dorsal vestiture and fine punctation and provided a simple illustration of the parameres of the male genitalia. The male genitalia of M. rubiginosa are strongly asymmetrical with a bundle of curled, robust setae at the apices; these constitute a set of autapomorphic characters within the tribe Melolonthini. Accordingly, Kryzhanovskij (1978) elevated Tocama to the generic level. Keith (2006Keith ( , 2007 subsequently described two new species and one new subspecies on the grounds of genital characters. Li et al. (2010) recently transferred two more species from the genus Melolontha and identified two Melolontha species with two Tocama species, respectively, and thus proposed two synonymies. Based on the examination of all known Tocama species, we include additional characters of the clypeus, pronotum, and patterns of setae and punctation along the descriptions of two new species from Indochina. A key to the males of the genus is also provided.

Material and methods
Specimens examined in this study were borrowed from the institutions (name of curators in acknowledgments) listed in the section of type material or came from the first author's personal collections.
The preparation of specimens and morphological terms used in this paper follow Li et al. (2010). Specimens and characters were examined and drawn using a Leica MZ12.5 stereomicroscope (Wetzlar, Germany) equipped with a drawing tube. The body length (BL) was measured from the apex of the clypeus to the apex of the elytra, and the body width (BW) was measured at the widest distance across the elytra. The abbreviations CL and BsL refer to the length of antennal club and basal segments, respectively, while PgW/L denote the ratio of pygidial width and length. Diagnosis. Tocama laosensis is distinguished from other congeners by the following combination of characters: body medium sized, thin, pronotum flat when viewed laterally (Fig. 4); head, pronotum and scutellum blackish brown, elytra dull castaneous; surface of pronotum, scutellum and elytra covered with tiny brownish grey setae, setae on vertex about 4 times length of those on pronotum and elytra; basal margin of elytra between scutellum and humeral umbone broadly ridged (Fig. 6); apical ridge of pygidium impressed and becoming concave inwardly along plane of disc; mesometasternal process vestigial; metepimeron and sides of abdominal sternites 1-6 with maculation consisting of brownish white, scale-like setae; male genitalia as in  (Fig. 4). Head, antennae, pronotum, scutellum and venter blackish brown; tarsomeres black; elytra dull castaneous; dorsal surface of body covered with minute, brownish grey setae. Head: Surface densely and coarsely punctate, each puncture with a seta, setae on clypeus thinner and shorter than those on vertex. Clypeus rectangular, bordered, with center apex emarginated; vertex slightly convex with setae about 4 times length of those on pronotum and elytra. Antennal club straight, subequal in length to basal segments. Labrum strongly bilobed at middle, symmetrical, each lobe rounded apically. Mentum with anterior margin moderately bilobed, surface sparsely setigerous, setae moderately long. Maxillary palpi short, apical palpomere about half length of antennomere 3. Pronotum: wider than long, widest at base, depressed when viewed laterally (Fig. 4); lateral margins well bordered, weakly developed anterior to scutellum; surface densely, evenly punctuate; punctures fine, each with a scale-like, tiny seta about 3 times length of diameter of puncture. Scutellum semicircular, surface with punctures and setae similar to those on pronotum. Elytron: Widest at middle; surface rugose with 4 weakly developed, punctate costae, costae 1-3 (starting from suture) complete, costa 4 vestigial; overall punctures and setae same as those on disc of pronotum; basal margin of elytra between scutellum and humeral umbone broadly ridged (Fig. 6). Propygidium: Surface densely punctate, punctures setigerous, setae similar to those on disc of pronotum with a row of more robust setae along apical margin. Pygidium: Lateral margins narrowly flattened. Surface densely punctuate; punctures setigerous, setae scale-like, longer and Figures 1-3. Dorsal habitus of Tocama spp. 1 Tocama laosensis sp. n., holotype male 2 Tocama procera sp. n., holotype male 3 Tocama procera sp. n., paratype female. more robust than those on pronotum, sparsely intermixed with hair-like, long setae (about 3-12 times longer than scale-like setae); pygidial apex truncate and concave inwardly along plane of disc (see Fig. 8 for T. procera), apical margin weakly quadrate. Venter: Prosternal process feebly protruding, apex not reaching base of protrochanter. Mesometasternal process vestigial. Metepisternum densely covered with hair-like setae. Metepimeron and sides of abdominal sternites 1-6 with maculation of brownish white, scale-like setae. Middle of abdominal sternites 1-4 almost impunctate, sides densely punctuate; punctures setigerous, setae fine, scale-like, intermixed with hairlike setae that are 3-15 times longer. Legs: Protibia tridentate with basal tooth weakly developed. Pro-and mesofemora flattened, surface hairy; hind femora stout, broad, surface clothed with much shorter, robust setae than those of pro-and mesofemora. Mesotibia with 2 apical spurs equal in length. Metatibia with dorsal apical spur reaching to middle of metatarsomere 2; ventral apical spur of metatibia subequal in length to metatarsomere 1. Parameres: In lateral view (Figs 10, 12), base of parameres (BP) constricted, ventroapical swelling of right paramere (RPvs) weakly developed. Middle of lateral margin smooth when viewed dorsally (Fig. 11).

Checklist of the genus
Female unknown.  Etymology. The species epithet is derived from the name of Laos, wherefrom it is described. This is the first Tocama species from this country and is probably endemic to it.
Remarks. Tocama laosensis is known from a single male specimen collected by a local collector, and it lacks further information. However, the type locality of the species is the southernmost distribution for the genus so far. Diagnosis. Based upon the shared characters of the presence of metepimeral maculation (as well as lacking metepisternal maculation (Fig. 17)), apex truncate of the pygydium and shape of the parameres, T. procera most closely resembles T. laosensis. T. procera differs from T. laosensis by the thickness of the pronotum when viewed laterally (flat in T. laosensis (Fig. 4), convex in T. procera (Fig. 5)), the shape of the anterior margin of the mentum (moderately bilobed in T. laosensis, straight in T. procera), length of setae on the anterior and lateral margins of the pronotum to length of those on the disc (2-4 times longer in T. laosensis, 4-8 times longer in T. procera), and the form of the basal margin of the elytra between the scutellum and humeral umbone (broadly ridged in T. laosensis (Fig. 6), feebly ridged in T. procera (Fig. 7)). Description. Males (Figs 2, 5): BL: 20.3-22.9 mm; BW: 11.4-11.8 mm; CL/ BsL=1.16-1.18; PgW/L= 1.25-1.33. Body thick, pronotum convex when viewed laterally (Fig. 5). Head, antennae, pronotum, scutellum and venter of body blackish brown, tarsomeres black, elytra dull castaneous, dorsal surface of body covered with minute, brownish grey setae. Head: Surface densely, coarsely punctate, each puncture with a seta, setae on clypeus thinner and shorter than those on vertex. Clypeus rectangular, bordered, emarginated apically; vertex moderately convex, covered with slender, hair-like and robust, scale-like setae, setae becoming longer laterally. Antennal club straight, subequal in length to basal segments. Labrum strongly bilobed at middle, symmetrical, each lobe rounded apically. Mentum with anterior margin straight, surface sparsely setigerous, setae moderately long. Maxillary palpi short, apical palpomere about 2/3 length of antennomere 3. Pronotum: Wider than long, widest at base, moderately convex when viewed laterally (Fig. 5); lateral margins well bordered but weakly developed anterior to scutellum; disc densely, evenly punctuate; punctures setigerous, fine, each with small, scale-like seta about 3 times longer than diameter of puncture, anterior and lateral margins with long, hair-like setae sparsely distributed, about 4-8 times longer than those on disc. Scutellum semicircular, surface with punctures and setae similar to those on pronotum. Elytron: Widest at middle. Surface rugose with 4 poorly developed, punctate costae between suture and humerus, sutural costa (as costa 1) and costae 2-3 complete, costa 4 vestigial; punctures and setae same as those on disc of pronotum; basal margin of elytra between scutellum and humeral umbone feebly ridged (Fig. 7). Propygidium: Surface densely punctuate, punctures setigerous; setae similar to those on disc of pronotum with a row of whitish, more robust setae along apical margin (Fig. 8). Pygidium: Lateral margins narrowly flattened. Surface densely punctate, puncture setigerous; setae scale-like, longer and more robust than those on pronotum, sparsely intermixed with long, hair-like setae (about 3-12 times longer than scale-like setae); pygidial apex truncate and concave inwardly along plane of disc (Fig.  8). Venter: Prosternal process moderately protruding, reaching base of protrochanter. Mesometasternal process feebly protruding. Metepisternum densely with hair-like setae (Fig. 17). Metepimeron and sides of abdominal sternites 1-6 with maculation consisting of brownish white, scale-like setae. Middle of abdominal sternites 1-4 almost impunctate with sides densely punctate, punctures setigerous, setae fine, scale-like, sparsely intermixed with hair-like setae 3-15 times longer. Legs: Protibia tridentate with basal tooth weakly developed. Pro-and mesofemora flattened, surface setose; hind femur more stout, surface clothed with much shorter, robust setae than those on pro-and mesofemora. Mesotibia with 2 apical spurs equal in length. Metatibia with dorso-apical spur reaching middle of metatarsomere 2; ventral apical spur of metatibia subequal in length to metatarsomere 1. Parameres: In lateral view, base of parameres (BP) strongly broadened, ventroapical swelling of right paramere (RPvs) distinctly developed (Figs 13, 15). Middle of lateral margin convex when viewed dorsally (Fig. 14).
Etymology. The species epithet, procera, is Latin for "tall" which refers to the relatively convex pronotum when viewed laterally. The name is a feminine adjective.
Remarks. Based on the collecting records of the type series, Tocama procera is geographically restricted to the mid-elevated (1,000-1,600m) montane areas of northern Vietnam where it occurs sympatrically withT. tonkinensis. However, T. tonkinensis has the broadest geographical range within the genus, ranging throughout northern Indochina (Vietnam, Laos, and Myanmar) northward to southern China (Yunnan, Guangxi, Guizhou, and Hunan). (Moser, 1913), comb. n. Remarks. Moser (1913) described Hoplosternus tonkinensis based from a female (labeled as "Tonkin [presently northern Vietnam] Montes Manson April. Mai 2-3000' H Fruhstorfer (printed) // Hoplosternus tonkinensis Type Mos (handwritten)", currently deposited at Museum für Naturkunde der Humboldt Universitat (ZMHB)), Berlin, Germany). Subsequently, he described H. pygidialis Moser, 1915, from a male (labeled as "Kiautschou [Guizhou Province] China (printed)// Hoplosternus pygidialis Type Mos (handwritten), deposited at ZMHB). We examined both type specimens and found that they share series of characters of pronotum shape, punctuation, setation, and male genitalia shape; these characters clearly indicate that the specimens are members of Tocama. Moreover, having examined large number of T. tonkinensis specimens (45 males and 43 females) from Indochina and China, we found that the sexual dimorphism of the species is particularly distinct in the shape of the pygidium, which might be the reason of separation for the previous two species by Julius Moser. We conclude that these two type specimens are conspecific.

Hoplosternus tonkinensis
Additionally, the intraspecific variation of T. tonkinensis is significant in body color. There are two main forms of body color, black and castaneous, that led Keith (2006Keith ( , 2007 to separation of T. atra atra (black form) and T. atra reichenbachi (castaneous form). We consider that they are all within the variability of T. tonkinensis based on the examination of the type series of T. atra atra and T. atra reichenbachi (see also Figs 5-6 in Keith (2006) for the shape of male genitalia). Accordingly, we herein transfer H. tonkinensis to Tocama and synonymize the names H. pygidialis, T. atra atra and T. atra reichenbachi with T. tonkinensis. Metepisternum with maculation (Fig. 16)