Merarius alexandrae Trýzna & Baňař, 2021

Trýzna, Miloš & Baňař, Petr, 2021, Review of the genus Merarius Fairmaire (Coleoptera: Anthribidae), with description of two new species from China, Zootaxa 5020 (2), pp. 367-383 : 369-371

Merarius alexandrae Trýzna & Baňař sp. nov.

( Figs 1–5 )

http://zoobank.org/ urn:lsid:zoobank.org:act:4FE12EC4-C1F1-423A-98F6-E6150A566BF3

Type locality. China, Yunnan prov., Dali zhou, Huadianba , 2800 m [ca. N 25°54´, E 99°50´]

Type material. Holotype (female). CHINA: ‘ China, Yunnan [prov.], Dali zhou, / Huadianba , 2800 m, / 22.- 24.vii.1993, / leg. C. Holzschuh [p]’ ( MMBC).

Red label [p] ‘ HOLOTYPE / Merarius / alexandrae sp. nov. / M. Trýzna & P. Baňař det., 2021 ’.

Identification. Species with two pairs of tubercles in preapical part of elytra; outer pair of tubercles noticeably longer than inner pair, all tubercles sharply pointed and oriented backwards. One pair of tubercles in sub-basal part beak-like, tips short, spiky and oriented backwards. Disc of pronotum with distinct deep transverse groove. Similar to Merarius davidis , but dorsal transverse carina of pronotum sinuate, forming wide arch oriented to base of elytra, not emarginate in middle. Longitudinal carina in middle part of rostrum reaching continuously to posterior margins of eyes, area between eyes without groove. Elytra and pronotum predominantly yellow to buff coloured, mixed with dark brown. Body size 6.50 mm, only holotype female known. Unique colour pattern as in Figs 1–2, 5 .

Description. Female holotype. Measurements (in mm): Total body length—6.50. Head: total length—1.75; length of rostrum—1.11; maximum width of rostrum—1.06; length of eye—0.66; maximum width across eyes— 1.16; minimum distance between eyes—0.29.Antenna: length of segments: II—0.20, III—0.21, IV—0.21, V—0.19, VI—0.13, VII—0.11, VIII—0.13, IX—0.24, X—0.13, XI—0.26, width of segment IX—0.20. Pronotum: maximum length—1.31; maximum width—2.31; minimum width—1.29. Elytra: maximum length—3.75; maximum width— 1.76. Pygidium: maximum length—0.63, maximum width—0.83.

Coloration of cuticle of entire body generally black to dark brown. Cuticle of head black with dark brown on gula and genae. Cuticle of elytra dark brown with light yellow transverse bands corresponding with area of lightcoloured setae. Base of each elytral fovea dark brown. Spikes of all tubercles (abraded) dark brown to black. All legs yellowish to light brown, funicles lighter coloured than scape, pedicel and club. Upper side of body light to dark brown with light yellow longitudinal stripes on lateral part of prosternum.

Vestiture ( Figs 1–2, 5 ). Head almost bare, with dark yellow appressed setae only on inner and posterior margin of eyes and stripe in median part of frons, genae with stripe of dark yellow appressed dense setae. Pronotum with one large triangular dark yellow spot covering entire area of disc, inside this spot two smaller black spots in lateral parts; disc with distinct but very slender longitudinal stripe with bright white appressed setae, erect setae mainly in part of transverse groove. Pronotal declivity with wide yellow band in median part. Prosternum with yellowish longitudinal stripes in lateral parts, basal margin of prosternum with very long erect setae. Elytra covered with dense appressed setae. Elytra with sub-basal wide yellowish band curved posteriorly, comprising humeral callus and posterior two thirds of tubercles. Median part of elytra with two tortuous transverse stripes, narrower and shorter than band in subbasal part. Area between inner small tubercles in sub-basal part covered with dark brown transverse spot. Elytral declivity with long greyish to whitish appressed setae, each elytron with two dark brown smaller spots in apical part. Meso-, metasternum and all abdominal ventrites covered with longer appressed to decumbent light-coloured setae. Antennae with very fine and delicate yellowish appressed setae. All femora with sparse appressed setae, tibiae with coarse subdecumbent dark setae, distal part of tibiae with ring of setae. All tarsomeres with coarse appressed dark setae. Pygidium covered with longer coarse yellowish setae.

Structure. Head relatively long, rostrum ( Fig. 3 ) with fine and dense punctures, distinct longitudinal carina reaching continuously from apical part of rostrum (here already indistinct) to posterior margins of eyes, in central part roof-like, carina here weakly elevated, lateral parts of rostrum descendent. Part between antennal scrobes more or less flat, with only shallow depressions between carina and lateral parts of rostrum. Rostrum narrowest at half its length, between anterior margins of eyes and scrobes. Dorsal and lateral parts of rostrum and frons gently sculptured. Area between eyes without groove, only indistinctly depressed. Ratio of rostrum length to maximum width 1.05. Dorsal ocular index 0.67. Ratio of maximum width across eyes to maximum width of rostrum 1.09. Antennae ( Fig. 4 ) reaching to middle of pronotum, only slightly exceeding the transverse groove on disc of pronotum. Scape and pedicel distinct, ca. twice as wide as antennomeres III, IX–XI forming compact club, this ca. twice as wide as width of pedicel. Antennomere IX only slightly longer than wider, X slightly transverse, XI slightly longer than wider. Pronotum distinctly transverse, ratio of its length to maximum width 0.57, widest at distinct dorsal transverse carina, from which it is strongly narrowed anteriad and posteriad ( Fig. 2 ). Dorsal sub-basal transverse carina sinuate, forming wide arch oriented to base of elytra, not emarginate in middle, continuously-undulate to sides, here distinctly anteriorly oriented and forming protruding lateral lobes ( Fig. 2 ). Lateral carina of pronotum very short, only slightly exceeding basal third of length of pronotum, in contact with dorsal transverse carina forming distinct lobes. Basal longitudinal carinulae of pronotum only weakly indicated. Disc of pronotum with distinct deep transverse groove. Elytra ( Figs 1, 5 ) broadly rectangular, sides almost parallel, narrowing suddenly in preapical part at point where tubercles are located, ratio of maximum length to maximum width of elytra 1.22. Elytra with one pair of prominent tubercles in sub-basal part, shape of tubercles beak like, with top on elytral interval II, tips short, spiky and oriented backwards. Preapical part of elytra with two pairs of tubercles oriented backwards: outer pair on elytral interval VI very long, narrow, with massive base, inner pair on elytral interval II, several times smaller than previous. Abdomen shorter than broad. Pygidium trapezoidal, wider than long, slightly narrowing posteriorly, ratio of the maximum length to maximum width 0.76.

Etymology. Matronym, dedicated to daughter of the first author, Alexandra Rassou (Innsbruck, Austria), a student of marine biology.

Collecting circumstances. Unknown.

Distribution. South China, Yunnan province.

Differential diagnosis. See key below.

Figures

FIGURES 1–5. Merarius alexandrae Trýzna & Baňař sp. nov., holotype female; 1, dorsal habitus [right hindtarsus omitted from the picture]; 2, pronotum in dorsal view; 3, head in dorsal view; 4, right antenna, dorsal view; 5, lateral habitus [apex of left hindtibia and hindtarsus omitted from the picture]. Scale bars in mm.