Two new species of Cerapanorpa (Mecoptera, Panorpidae) from the Qinling and Minshan mountains

Abstract Two new species of Cerapanorpa Gao, Ma & Hua, 2016 are described from the Qinling and Minshan mountains, respectively. Cerapanorpa qinlingensissp. nov. can be readily distinguished from its congeners by the elongate hypovalves and the extremely developed basal process of gonostylus in male genitalia. Cerapanorpa minshanasp. nov. is characterized by its bifurcated parameres and a cluster of long black bristles on the inner apex of the gonocoxite. The number of species of Cerapanorpa is raised to 21. An updated key to species of Cerapanorpa is presented.


Introduction
The single-horned scorpionfly Cerapanorpa Gao, Ma & Hua, 2016, an endemic genus of Panorpidae (Insecta, Mecoptera) in central China , is mainly characterized by a finger-like anal horn on the posterior margin of tergum VI in males, and a medigynium bearing two pairs of basal plates on both sides of the main plate and an elongate rod-like axis with a pair of weakly divergent arms in females (Ma et al. 2012;Gao et al. 2016;Gao and Hua 2019). Species of Cerapanorpa are widely distributed in the Qinling-Bashan Mountains and adjacent regions, with an altitude ranging from 1400 m to 2800 m . The habitats are cool or humid during their flight period, generally including groundcover in broad-leaf forests, mixed forests, and alpine shrub meadows .
The eggs are oval and bear polygonal net-like ridges on the chorion surface (Li et al. 2007;Ma et al. 2009). The saprophagous larvae are eruciform and epedaphic, bearing eight pairs of abdominal prolegs, and usually overwinter as grown larvae in soil cavities (Jiang and Hua 2015;Jiang et al. 2019). The larvae possess a pair of compound eyes consisting of ⁓30 ommatidia (Chen et al. 2012), which almost have the same cellular components as those of their adults although the tiering scheme is different (Chen and Hua 2016). During mating, the male usually secretes a salivary mass as a nuptial gift to attract the female prior to copulation, and uses its single anal horn to clamp the female's abdominal segment to maintain copulation (Tong et al. 2018).
Cerapanorpa currently consists of 19 species , which not only display similar internal anatomy (Hou and Hua 2008;Ma et al. 2011), but also have a strongly supported monophyly by phylogenetic analyses (Ma et al. 2012;Hu et al. 2015;Miao et al. 2017Miao et al. , 2019. The alimentary canals are similar in gross morpholgy (Liu and Hua 2009). The male salivary glands uniformly possess six secretory tubes with similar configuration and size (Ma et al. 2011).
Recently, two undescribed species of Cerapanorpa were collected from the Qinling and Minshan mountains, a well-known biodiversity hotspot in the world (Myers et al. 2000;Tang et al. 2006;Hu et al. 2019), and are described as new species herein. The number of species of Cerapanorpa is raised to 21.

Material and methods
Specimens were collected from the Qinling and Minshan mountains in central China ( Fig. 1), and deposited in the Entomological Museum, Northwest A&F University, China (NWAU). Specimens were dissected under a Nikon SMZ 1500 Stereoscopic Zoom microscope. Genitalia were macerated in cold 5% NaOH solution for 3 min and rinsed with distilled water. Wings were measured with a vernier calliper. Adult photographs were taken with a Nikon D7100 digital camera, other images were taken using a scientific digital micrography system, ZEISS SteREO Discovery.V20 equipped with an auto-montage imaging system AxioCam IC. The distribution map was constructed using ArcGIS v10.2 and Adobe Illustrator CC. All photographs were assembled with Adobe Photoshop CS6.
Terminology follows Gao et al. (2016), Hua et al. (2018) and . The following abbreviations and acronyms are applied: A1, first abdominal segment (and so forth for other segments); T1, first tergum (and so forth for other segments). Etymology. The specific epithet refers to the type locality, Qinling Mountains. Diagnosis. The new species resembles C. emarginata (Cheng, 1949) in appearance, but can be readily distinguished from the latter by the following characters: 1) wing markings greatly reduced with a faint pterostigmal band (cf. with conspicuous pterostigmal band and apical band); 2) hypovalve longer, reaching the apex of the gonocoxite (cf. shorter, not reaching apex of gonocoxite); 3) paramere shorter, reaching the middle of the gonostylus (cf. longer, reaching apex of gonostylus); 4) gonostylus with an extremely developed basal process (cf. poorly developed).
Abdomen (Figs 2E,4A). T2-T5 blackish, pleura ivory. Notal organ of T3 very short, not prominent. Postnotal organ of T4 small, hook-shaped and projecting forward. A6 uniformly brownish black, with a brown finger-like anal horn on posterior margin of tergite. A7-A8 elongate and yellowish brown, slightly constricted at base, gradually wider toward apices. A7 with a narrow groove at base. (Fig. 3A, B). Genital bulb yellowish and long oval. Epandrium long and broad, with a nearly trapezoidal emargination distally. Paired hypovalves slender, reaching apex of gonocoxite, bearing a column of long bristles along inner margin. Gonocoxite with a small concave area on apical inner margin, bearing two small protuberances on ventral submedian margin. Gonostylus medially curved, with an indistinct median tooth and an extremely developed basal process on inner margin, and bearing a bundle of short setae dorsally on basal process (Fig. 3C). Parameres extending well beyond base of gonostylus ( Fig. 3A), curved distally and pointed apically, bearing a row of dense spines along inner margin (Fig. 3G). Aedeagus sclerotized; dorsal valves of aedeagus long, curved ventrally, with distal part pediform; ventral valves short, membranous; lateral process not prominent (Fig. 3D, F).
Habitat. In the type locality, Taibaishan Nature Reserve, all specimens were captured on the southern slope of the Taibai Mountain, with an elevation of 2100 m. The species mainly inhabits dense herbaceous and shrubby vegetation under evergreen broad-leaved forests (Fig. 4C). Etymology. The specific epithet refers to the type locality, Minshan Mountains. Diagnosis. The new species can be readily distinguished from its congeners by the following combination of features: 1) paramere short and bifurcated, bearing a column of long golden spines along the dorsal side; 2) gonocoxite bearing a cluster of black long bristles on the inner apex; 3) dorsal valves of the aedeagus curved ventrally, with the distal part heel-shaped; 4) main plate of medigynium flat, intensely narrowed at the base and broadened distally.
Male genitalia (Fig. 6A, B). Genital bulb globular and yellowish brown. Epandrium broad basally, narrowing gradually toward apex, with a deep U-shaped emargination between two stout setose lobes (Fig. 6B). Paired hypovalves parallel, only reaching three-quarters of gonocoxite, bearing long bristles along inner margins. Gonocoxite bearing a cluster of black bristles on inner apex (Fig. 6A). Gonostylus shorter than gonocoxite, medially curved, bearing an indistinct middle tooth and a large basal process. Parameres bifurcated and short, not extending beyond the apex of gonocoxite, bearing a column of long golden spines along dorsal side (Fig. 6C, E). Dorsal valves of aedeagus curved ventrally, with distal part heel-shaped (Fig. 6F); ventral valves membranous, weakly developed; lateral process long and curved ventrally.

Distribution. China (Minshan, Sichuan and Gansu provinces).
Habitat. In the type locality, all specimens were captured on herbaceous groundcover in the Panjiagou Valley (Fig. 7C), with an elevation of 2400 m. Suitable microhabitats in the valley are moist and cool during the imaginal flight period, with the temperature ranging approximately from 14 to 20°C during the day. Paramere yellowish brown, blunt apically, reaching middle of gonostylus and bearing spines along inner margin .

Discussion
Cerapanorpa qinlingensis sp. nov. is endemic to the western Qinling Mountains, and closely related to C. emarginata (Cheng, 1949), which is patchily distributed in the eastern Qinling Mountains. The parapatric distribution pattern of these two species probably provides an ideal model to examine the mechanisms of species differentia-tion or speciation (an east-west genetic break) in the Qinling Mountains, as previously uncovered by phylogeographic studies (Wang et al. 2012(Wang et al. , 2013Liu et al. 2014;Huang et al. 2017).
The discovery of C. minshana sp. nov. increases the diversity of the genus Cerapanorpa to five species in the Minshan Mountains, including C. bonis (Cheng, 1949), C. baimaensis , C. xuebaodinga Gao & Hua, 2019, C. yanggashana Gao & Hua, 2019. Cerapanorpa minshana sp. nov. differs greatly from the aforementioned four species by its bifurcated paramere, the shape of dorsal aedeagal valves and a cluster of black bristles on inner apex of gonocoxite. Only two species, C. minshana sp. nov. and C. centralis (Tjeder, 1936), possess a cluster of long black bristles on inner apex of gonocoxite in Cerapanorpa. However, C. minshana sp. nov. can be readily distinguished from C. centralis by its specific bifurcated paramere and the shape of dorsal aedeagal valves in males.
Cerapanorpa qinlingensis sp. nov. and C. minshana sp. nov. are only found in the high-altitude microhabitats of the Qinling and Minshan mountains, respectively (Figs 4C, 7C). These fragmented habitat islands are cool and humid, generally with an altitude above 2000 m (Fig. 1). Most species of Cerapanorpa prefer these cool habitats, and usually inhabit the 'sky islands' of mountain tops in these mountainous regions . Compared with other genera (such as Panorpa Linnaeus, 1758 and Neopanorpa van der Weele, 1909), which have a broad spectrum of distribution in elevation Hua 2017, 2019;, Cerapanorpa is likely a cold-adapted genus in Panorpidae.