Pectotibialis paghmanensis Tshernyshev gen. nov. – a new genus and species of soft-winged flower beetle (Coleoptera, Cleroidea, Malachiidae) from Afghanistan

A new genus with a new species of soft-winged flower beetle, Pectotibialis paghmanensis Tshernyshev gen. et sp. nov. are described from Afghanistan. The new genus can be distinguished from the congeners of the tribe Apalochrini by the dark pectination in the apices of tibiae in both sexes, and the anterior tibiae which are hollowed at distal half, flattened and rounded femora, bituberculate basal parts of head and pronotum, two lamellate metathoracic appendages, tarsal comb above second tarsomere of anterior legs, and serrate antennae in the male. Based on the metathoracic appendages and comb in anterior legs would attribute this new species to the new genus Dromanthomorphus Pic, 1921, but all the other above-mentioned characters define its independent status and the designation of a new genus; Pectotibialis Tshernyshev gen. nov. The external appearance, special male characters and genitalia of the type species of the new genus are illustrated, and a distribution map is provided. A key to the Apalochrus-section of the tribe Apalochrini is provided.


Introduction
Amongst the soft-winged fl ower beetles obtained by my colleague Oleg Pak in Afghanistan were several specimens of narrow, parallel-sided malachiids resembling representatives of the genus Apalochrus Erichson, 1840 and belonging to the tribe Apalochrini. The male has with a comb above the second tarsomere in the anterior legs, and this character allows this species to be placed near Protapalochrus Evers, 1987. Both genera, Apalochrus Erichson and Protapalochrus Evers, are distributed in Central Asia, and two species, A. fl avicollis Schaufuss, 1870 and P. (P.) fedtschenkoi (Solsky, 1882), are known from Afghanistan (Mayor 2003(Mayor , 2007Tshernyshev 2015cTshernyshev , 2016b; however, the newly found taxon differs from them by the monochromous dark colouration of its surface which lacks yellow-orange spots. Further study of the male has revealed characters previously unknown in any members of the tribe Apalochrini Mulsant & Rey, 1867. The metathorax is swollen and impressed in the middle, with two lamellate appendages located below, near distal edge, and above, closer to mesothorax. The metathoracic appendages allow placing this species near Dromanthomorphus Pic, 1921, but species of this genus have only one appendage at the base of metathorax which is not lamellate and a different shape, and they also have swollen intermediate tibiae. These characters show that the species found in Afghanistan is different from Dromanthomorphus Pic. Another genus of the tribe with a thorn-like metathoracic appendage, Mimapalochrus Tshernyshev, 2015, occurs in SE Asia and is distinguishable by the elytral apices impressed near the suture, swollen anterior and an intermediate femora, simple not emarginate anterior tibiae slightly widened posteriorly, the presence of pheromone glands on intermediate tibiae, and extremely large eyes. Hence, the newly found species does not belong to any known genera of the tribe Apalochrini and represents a new genus and new species. The tribe Apalochrini unites soft-winged fl ower beetles with typical antennae possessing a second antennomere which is extremely small, round or oval, usually almost completely hidden by the scape, so that the antennae appear to be 10-segmented. The highest species diversity of the tribe occurs in SE Asia, Africa and Australia where species have a wide spectrum of male characters of importance to differentiate taxa. The taxonomic structure of the tribe has been recently discussed with special reference to southern Asian genera, and, a number of recent articles devoted to, or pertaining to, the Malachiidae Fleming, 1821 fauna of the Himalayas and an area of south-east Asia and Australia have been published (Yoshitomi 2008(Yoshitomi , 2010(Yoshitomi , 2014Asano & Kojima 2009, 2013, 2014Tshernyshev 2009Tshernyshev , 2012bTshernyshev , 2015aTshernyshev -e, 2016aTshernyshev -d, 2018Tshernyshev , 2020aAsano & Kawashima 2010;Yoshitomi & Lee 2010;Asano & Yoshitomi 2011;Asano et al. 2011aAsano et al. , 2011bAsano et al. , 2018Geiser 2011;Asano 2013aAsano , 2013bAsano , 2015Asano , 2017Asano , 2018Asano & Okajima 2013;Plonski 2013Plonski , 2014aPlonski , 2014bPlonski , 2015Plonski , 2016Plonski , 2017Plonski & Geiser 2014;Plonski & Michael 2014;Plonski & Puchner 2014;Constantin 2015;Liu et al. 2015Liu et al. , 2016Liu et al. , 2017Yoshitomi et al. 2015;Tshernyshev & Kopetz 2018;Tshernyshev & Shcherbakov 2020); however, further revision is still necessary to clarify our knowledge of the taxonomy.
However, the complex of male special characters for the new Afghanistan species necessitates a new genus, Pectotibialis Tshernyshev gen. nov., as described below, with Pectotibialis paghmanensis Tshernyshev sp. nov. selected as the type species.

Material and methods
For descriptions, special male structures and genitalia were studied; ‛special male structures' refer to the sculptured head and pronotum, swollen, impressed and appendiculate metathorax, and excavate anterior tibiae. Illustrations for the species were prepared using specimens from the type locality: Pectotibialis paghmanensis Tshernyshev sp. nov. holotype, male and paratype, female -Afghanistan, Kabul Province , near Paghman village.
The specimens are currently deposited in the following institution, which is subsequently referred to by the acronym:

SCH_ISEA
= the author's collection, which is housed in the Institute of Animal Systematics and Ecology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
The beetles were studied using an Amscope trinocular stereomicroscope (Ultimate Trinocular Zoom Microscope 6.7X-90X Model ZM-2TY), and digital photographs were taken using a Carl Zeiss Stemi 2000 trinocular microscope and the AxioVision programme. Male genitalia, embedded in DMHF (Dimethyl hydantoin formaldehyde), were mounted onto a transparent card and pinned under the specimen.

Type species
Pectotibialis paghmanensis Tshernyshev sp. nov. fi xed by monotypy in the present paper.

Diagnosis
Moderately small sized (ca 3.8-4.1 mm) soft-winged fl ower beetles with the body elongate, narrow, parallel-sided, slightly expanded posteriorly, with two or three apical ventrites of the abdomen not covered by elytra. Metallic green upperside with yellow or yellow-brown parts, i.e., labrum, labium, mandibles, palpi, mouthparts and antennae, tibiae and tarsi in all legs, coxae and trochanters of anterior legs and areas of joining between them in intermediate and posterior legs. Antennae weakly fl abellate, not long, expanding over the base of elytra, with the 3 rd antennomere wide triangular. Head small, narrower than pronotum, interocular area slightly impressed and sculptured, frons tuberculate, eyes simple, not large, slightly protruding. Pronotum almost completely equilateral, narrowly transverse, impressed near basal margin, disk convex with wide subtriangular tubercle in the middle and looking bituberculate, basal side and basal half of lateral sides slightly fl attened and distinctly marginate, and anterior side indistinctly marginate. Elytra parallel or slightly widened just below the middle, not covering two or three apical segments of the abdomen, coarsely punctured, with distinct and weakly protruding shoulders; apices evenly rounded, simple. Hind wings normally developed (in both sexes). Anterior tarsi with distinct transverse small comb above the 2 nd tarsomere and wide triangular 1 st tarsomere; claws very short and hidden by round transparent plates at base. Anterior tibiae strongly excavate dorsally in apical half with elongate tip looking like initial tarsomere, not swollen; intermediate and posterior tibiae simple, not swollen or emarginate, with the setae similar to that in tarsal comb arranged in apical edge near tarsus. Femora wide, roundly swollen, anterior with a dent in middle. Anterior trochanters oval and impressed to the basal half of the femur.
Metathorax swollen and impressed in the middle with two appendages, one lamellate transverse above, and the other longitudinal with a vertical round semi-transparent plate at apex. Pygidium elongate, equilateral, evenly rounded distally, ultimate abdominal ventrite bilaciniate, narrow, transverse, evenly narrowed dorsally and emarginate in the middle, aedeagus simple, weakly curved dorsally, narrow, with elongate narrow apical lamella, endophallus with a few denticles at apex of inner sac, tegmen long, narrow, with thin, short pointed parameres.

Comparison
Special male characters differentiating Pectotibialis Tshernyshev gen. nov. from all other members in the tribe Apalochrini are given in the key below. The new genus is similar to the genera Dromanthomorphus Pic and Oculapalochrus Tshernyshev in the presence of appendages on the metathorax and tarsal comb above the second tarsomere in the anterior legs of the male, but typical characters that differentiate it are as follows: distinguished from Dromanthomorphus Pic by simple, not widened intermediate tibiae and from Oculapalochrus Tshernyshev by simple eyes; the strongly excavate anterior tibiae in combination with the abbreviated elytra of the new genus are different from both genera.

Notes
This species and genus are known only from Afghanistan, Central Asia.  HEAD. Not wider than pronotum, interocular area slightly impressed and edged with thin carina, frons with two tubercles, eyes small, oval, weakly protruding; genae short and straight; clypeus narrow, transverse, straight; labrum narrow, transverse; palpae simple with apical segment slightly widened and securiform; surface of head dull, sparsely indistinctly punctured lacking microsculpture, evenly covered with light fi ne long and curved pubescence.

List of species in the genus
ANTENNAE. Weakly fl abellate from 6 th to 11 th antennomeres (Fig. 1D), 1.7 mm long, reaching the base of elytra; 1 st antennomere enlarged, round-oval, 2 nd antennomere small, round, almost completely invisible, hidden by the 1 st antennomere, 3 rd and 4 th antennomeres triangular, the 3 rd is 1.2 times as long and wide as the 4 th antennomere, 5 th antennomere triangular with elongate outer edge and is as long as the 3 rd antennomere, but considerably narrower than it, 6 th to 10 th antennomeres with extended outer edges, apical segment elongate, thin, subcylindrical, slightly curved in basal third; surface evenly covered with short, yellowwhite adpressed pubescence with single erect longer light hairs on outer sides of the antennomeres.
PRONOTUM. Almost completely equilateral, narrowly transverse impressed near basal margin, disk convex with wide subtriangular tubercle in a middle and look bituberculate at base; anterior margin slightly convex; posterior margin straight; lateral sides almost completely straight with rounded angles; basal side and basal half of lateral sides slightly fl attened and distinctly marginate, anterior side indistinctly marginate; surface glabrous, with sparse smoothed punctures lacking microsculpture, evenly covered with fi ne long curved light hairs.
SCUTELLUM. Small, triangular with rounded tip, almost completely covered by pronotum, sparsely punctured and covered with light semi-erect hairs.
ELYTRA. Oblong, parallel or slightly widened just behind the middle and evenly rounded distally, not covering three apical segments of the abdomen, at base not wider than pronotum; humeri small, slightly protruding; apices evenly rounded, simple; disc indistinctly marginate on external sides and along suture, lateral edge in middle near epipleura slightly impressed; surface dull, coarsely punctured and wrinkled, with smoothed microsculpture, evenly covered with yellow-white long erect hairs. HIND WINGS. Normally developed. LEGS. Not long; posterior femora not reaching elytral apices; anterior tibiae not swollen but widened distally and with a strong rectangular excavation inwardly in apical half so that the tip of the tibiae looks like a 1 st tarsomere ( Fig. 1H-I), intermediate and posterior tibiae simple, not swollen or emarginate, with the setae similar to that in tarsal comb arranged in apical edge near tarsus, femora wide, roundly swollen, anterior with tooth in middle ( Fig. 2A-B), anterior trochanter oval and impressed to the basal half of the femur, all tarsi 5-segmented, slightly compressed and elongate, 2 nd tarsomere in anterior tarsi with small transverse comb above, the 1 st tarsomere enlarged, triangular, 1.3 times as long as the 2 nd tarsomere, 2 times as long as the 3 rd tarsomere and 3 times as long as the 4 th tarsomere, claw-segment fl attened, as long as the 1 st tarsomere, claws very short and thin, almost completely hidden by round semi-transparent membrane at base. Surface of legs covered with light short semi-erect pubescence and sparse white long erect hairs. VENTRAL BODY SURFACE. Sparsely punctured, shining, evenly and sparsely covered with long, fi ne, semierect white hairs; metathorax swollen and complicatedly sculptured: impressed in a middle, and with two protuberances, one lamellate transverse above, and the other longitudinal and possessing vertical round semi-transparent plate at apex (Fig. 1F-G). Pygidium slightly elongate, almost equilateral, evenly rounded distally, with long dark erect hair on outer side (Fig. 2C), ultimate abdominal ventrite is bilaciniate, narrow, transverse, evenly narrowed dorsally and emarginate in the middle (Fig. 2D), aedeagus simple, weakly curved dorsally, narrow, with elongate narrow and ventrally curved apical lamella, endophallus with three denticles at apex near lamella (Fig. 2F), tegmen long, narrow, with thin and short pointed parameres those are 2.3 times as short as the base of tegmen (Fig. 2G).
Female differs in having simple head and pronotum lacking sculpture, anterior tarsi simple, lacking a comb above the 2 nd tarsomere, antennae dentate with the 3 rd and 4 th antennomeres narrow-triangular, and of the equal shape and length, anterior tibiae lacking excavation, but with stretched outer edge bearing the 1 st tarsomere, anterior femora lacking tooth, metathorax evenly convex lacking appendages, inner side of the apex of anterior and intermediate tibiae with a row of setae similar to that in tarsal comb of male, abdomen long, with four segments extending beyond apex of the elytra.
Representatives of the fi rst group are typical residents of Eurasia, Indo-China, South East Asia, Australia and Africa with high species diversity in southern regions (Tshernyshev 2011(Tshernyshev , 2012a. Species of the second group are also occurring in these regions, but most diverse in Australia and also represented in American continent. Due to the absence of their fragments in fossil remains, the tribe Apalochrini can be considered as the youngest in the family Malachiidae, and, probably originated from the tribe Illopini, that is also similar to Malachiini due to the small size of the second antennomere. The wide species distribution, from Africa to Arctic region of Eurasia, allows a high evolutionary potential of the tribe in adaptation to different type of habitats to be assumed. The tribe is at present being actively studied, and the description of several new species from southern regions is to be expected in the nearest future. The present generic revision can help in the understanding of the taxonomic diversity of the family Malachiidae and the remarkable tribe Apalochrini.