Croscherichia armass Ruiz, Francois & Garcia-Paris

Ruiz, Jose L., Francois, Alexandre & Garcia-Paris, Mario, 2019, A new singular species of Croscherichia Pardo Alcaide, 1950 (Coleoptera, Meloidae, Mylabrini) from arid zones of eastern Morocco, ZooKeys 885, pp. 27-50 : 27

Croscherichia armass Ruiz, Francois & Garcia-Paris sp. nov Figs 1 A–D , 3 A–D , 4 , 5A, B , 6 A–D , 7

Type material.

Holotype: 1 male (dry-preserved) ( Fig. 3 ), labelled: "10/09/2015, Missour ECWP, 33.00722 / -4.0977600, A. François” / "954 m, Steppe à Hammada scoparia , Sur fleurs d’ Atriplex halimus " (ivory labels, printed); "Holotypus, Croscherichia armass Ruiz, François et García-París des. 2018" (red label, printed). Paratypes: 2 males, 4 females (dry-preserved), labelled: "12/09/2002, Missour Al Baten, 33.16433 / -4.01064, J. Yvernault" / "032P1-2 BD019, Surface dépandage, Salsola vermiculata " (ivory labels, printed); 1 female, labelled: "13/09/2002, Missour Al Baten, 33.20696 / -3.8697, J. Yvernault" / “Piège Barber 09p4-3, Surface d’epandage, Salsola sieberi et Peganum hamala , B032AB" (ivory labels, printed); 4 males, 11 females (2 males and 9 females dry-preserved, 2 males and 2 females preserved in ethanol), labelled: "10/09/2015, Missour ECWP, 33.00722 / -4.0977600, A. François” / "954 m, Steppe à Hammada scoparia , Sur fleurs d’ Atriplex halimus " (ivory labels, printed). All paratypes labelled: "Paratypus, Croscherichia armass Ruiz, François et García-París des. 2018" (red labels, printed).

Description of holotype (male):

Total length: 9.1 mm. Maximum width: 2.85 mm. General appearance elongated, stylized ( Fig. 3 ). General coloration of the body tegument black, with orange legs, except tarsi that are chestnut brown, almost black. Antennae black, with antennomeres II, III, and the central area of I brownish. Elytra tricolored, reddish orange, with bands and black spots widely fringed with a halo of yellowish-ivory coloration lighter than the rest of the elytral integument; the contrast in coloration is especially noticeable in vivo. Very dense, greyish-silver body pubescence applied against the integument and mostly masking it, giving the body (except the elytra) a silvery grey appearance; pubescence on the elytra very short, with very fine and erect hairs.

Head ( Fig. 3B, C, D ) widely rounded and broad in frontal view, without grooves or depressions, regular and weakly arched at vertex level, relatively narrow and short in lateral view; maximum width in front view: 1.75 mm; vertex to clypeo-frontal suture length: 1.26 mm; minimum width between the eyes (at the level of the front): 1.1 mm; short and broadly rounded temples, with a "maximum eye width (smaller diameter) to temple length" ratio of 1.02. Tegumentary surface glossy black with very thin microreticulation, presenting a small circular red spot that is diffuse but highly visible in the centre of the forehead at the level of the upper lobes of the eyes. Eyes convex but not very protuberant, slightly projecting from the natural convexity of the head, weakly notched at the level of the antennal insertions and with a very fine perimeter rim; larger diameter: 0.87 mm, smaller diameter: 0.51 mm. Forehead flat, except for a very small and diffuse central gibbosity at the level of the red spot, with a broad central zone, smooth and shiny, with a triangular outline, at the posterior end of which is the red spot. Vertex broadly arched, without a central longitudinal groove. Net, deep, arched clypeo-frontal suture. Clypeus transverse, 1.91 times wider than long, black, with the anterior half semimembranous and impunctate. Labrum relatively elongated, 1.4 times wider than long, with arcuate sides and the anterior margin slightly notched in the middle, with a narrow, weak, and diffuse central longitudinal line; black, except for an antero-central triangular zone with a semimembranous brownish-grey appearance, located just behind the notch. Cephalic capsule with fine but net and deep, dense punctures that are spaced apart by 0.5 to 1.0 times their diameter, except in the smooth disc region of the forehead; the highest density of punctures appears between the smooth zone and the inner margins of the eyes, as well as behind them and in a transverse band between the clypeo-frontal suture and the posterior margin of the antennal insertions; the lowest density occurs in the posterior region of the temples and vertex. Punctures of the clypeus restricted to the posterior half, puncture points slightly thicker and denser than those on the forehead, contiguous, almost masked by the dense setation; punctures of the labrum similar to that of the clypeus in a narrow basal region but thicker and scattered on the rest of the surface. Setation of the head greyish silver, relatively dense and semi-erect or stretched (according to zones), following the pattern of the punctures in which it is inserted; longer and denser setation around the eyes, side areas of the temples, and in a transverse strip located between the clypeo-frontal suture and the posterior margin of the antennal insertions; shorter and less dense setation on the sides and posterior regions of the frons and vertex; setation of the vertex and the posterior area of the frons, stretched and forward-facing; setation of the sides of the forehead and the bands around the eyes semi-erect and directed towards the smooth disc; the setation inserted into the anterior transverse band of the forehead (between the antennal insertions and the clypeo-frontal suture), semi-erect and directed symmetrically toward the centre (of each half); setation of the temples mostly lying on the integument and directed forward, except for some long erect hairs located along the latero-ventral region that are directed downwards. Setation of the clypeus restricted to the posterior half, following the pattern of the punctures in which it is inserted, dense, semi-erected, and directed forward, with longer hairs on the sides and shorter hairs in the centre. Setation of the labrum very scarce and constituted by some hairs that are dispersed, fine and semi-erect, similar to those of the clypeal sides. Ventral region of the head, except the sides, smooth and hairless. Mandibles black, shiny, narrow, with their outer margins almost straight, except at the apical end where they are slightly curved; almost entirely hidden by the labrum in dorsal view. Maxillary palps short and black, with scarce setation similar to that of the labrum and subcylindrical segments slightly widened toward the extremity, the basal segment very short and the distal one truncated at the apex. Labial palps short and black with subconical palpomeres, the basal palpomere very small and the distal one truncated at the apex and slightly thickened towards the end. Dark brown ligule, notched at its anterior margin and with a deep longitudinal groove.

Antennae ( Fig. 3C, D ) with 11 antennomeres: antennomere I black, with a dark brown coloration in the central zone; antennomeres II, III, and the basal zone of IV dark chestnut, bright; antennomeres IV (except in a basal ring) to X, black; antennomere XI black, with a dark brown area in the apex; antennomeres IV and V shiny, antennomeres VI to XI less shiny. Antennae relatively long, and when extended backwards, they reach the third quarter of the pronotum, weakly and gradually thickening toward the end from antennomere V. Length of the right antenna (extended): 2.92 mm; antennomere I elongated (length, l = 0.56 mm; maximum width, w = 0.19 mm; l/w: 2.94), slightly curved in the middle and slightly thickened at the end, with semi-lying, whitish, setation similar to that of the labrum but shorter; antennomere II short (l = 0.18 mm; w = 0.17 mm; l/w = 1.05), subcylindrical in the basal half and globose in the distal half, with setation similar to antennomere I but shorter; antennomere III narrow, elongated (l = 0.27 mm; w = 0.18 mm; l/w = 1.5), subconical, with pubescence similar to antennomere II; antennomeres IV (1 = 0.17 mm; w = 0.2 mm; l/w = 0.85) and V (1 = 0.18 mm; w = 0.24 mm; l/w = 0.75), short and wide, transverse, with setation similar to antennomere III but with scarcer and shorter hairs; antennomere VI transverse, wide (1 = 0.21 mm; w = 0.26 mm; l/w = 0.8), with very few hairs similar to those of antennomere V; antennomere VII subcylindrical, slightly wider at the distal end (1 = 0.24 mm; w = 0.26 mm; l/w = 0.92); antennomeres VIII (1 = 0.26 mm; w = 0.28 mm; l/w = 0.92), IX (1 = 0.28 mm; w = 0.26 mm; l/w = 1.07) and X (1 = 0.3 mm; w = 0.29 mm; l/w = 1.03) cylindrical and subequal; antennomere XI (1 = 0.5 mm; w = 0.27 mm; l/w = 1.85) cylindrical in the basal half and conical in the distal half, with a blunt tip; setation of antennomeres VI to XI hardly noticeable, whitish yellow, and applied to the tegument surface, with a few hairs longer, thin and erect.

Pronotum ( Fig. 3A, B, D ) with glossy black tegument, with hardly noticeable fine microrreticulation; with a predominantly silver appearance due to the dense setation that covers the pronotal surface, except for a central depression and two smooth zones at its sides; almost as long as wide; length along the mid-line: 1.62 mm; maximum width, measured between the second and third pronotal fifth (at the level of the lateral angles): 1.65 mm; shape subquadrangular to trapezoidal in dorsal view, weakly truncated anteriorly; in lateral view, markedly sloping from lateral angles forward, backwards smoothly convex; lateral margins converging in the anterior-most two fifths and sinuated in the posterior-most three fifths; lateral angles well marked, protruding in dorsal view and rounded, like the anterior ones; posterior angles obtuse and rounded; basal region very weakly notched in the centre, directly facing the scutellum, with a very fine rim, masked by a line of dense, short, and semi-erect hairs directed towards the centre. Pronotal macrosculpture constituted by a central depression (located approximately in the pronotal third fifth) that appears as a longitudinal fossa with fuzzy borders, smooth, with a length of approximately 0.34 mm and a maximum width of 0.14 mm, and two broad slightly elevated symmetrical areas, smooth and hairless, ovoid in outline, widest in the posterior area, obliquely located on both sides of the discal depression, almost reaching the pronotal basis. Pronotal sculpture barely visible, mostly hidden by dense setation, consisting of thin, net punctures similar to those of the forehead, dense, subconfluent, uniformly distributed throughout the surface except for the central depression and the two smooth areas. Setation silvery, dense, relatively long and thick, mostly applied against the pronotal surface, and distributed according to the pattern of punctures in which it is inserted; setation directed backwards in the anterior-most two fifths, towards the centre on the sides, and forward in the posterior fifth; the setation surrounding the central depression is semi-erect and radially and outwardly directed; the setation located along the inner margins of the smooth areas is semi-eccentric and directed forward; the ends of the hairs from these two areas (central depression and smooth areas) overlap, giving rise to two bands of hairs with the appearance of a long tuft.

Scutellum hemi-elliptic, rounded along its posterior margin, with black and shiny integument, very densely and finely punctured, with a setation that completely covers the surface, similar to that of the pronotum, giving it a silvery appearance.

Elytra ( Fig. 3A, B ) elongate, subparallel, with the humeral region slightly protruding and broadly rounded; length from the base of the pronotum to the apical end: 6.15 mm; maximum width, measuring both elytra together at the third quarter: 2.9 mm; semi-glossy surface; background coloration reddish orange, with a band and several black spots with well-defined contours surrounded by a broad, diffuse, yellowish-ivory halo; with the following design: (1) a small basal hemi-elliptic black spot contiguous to the humeral (prehumeral) region, which is almost completely covered by the posterior angular margins of the pronotum, that continues toward the centre as a thick line that borders the scutellum and, from the end of it, extends towards the elytral suture; (2) an anterior transverse series of three elliptic spots, clearly separated, aligned and located approximately in the posterior area of the anterior third of the elytron; the inner spot almost rounded and well separated from the suture, with its major axis (Ma) positioned transversely (Ma = 0.32 mm; minor axis, ma = 0.24 mm, measured on the left elytron); the central spot, closer to the external spot, is the largest, with its Ma positioned longitudinally (Ma = 0.70 mm, ma = 0.40 mm); the external spot, similar to but smaller than the central one (Ma = 0.50 mm, ma = 0.36 mm), is located in the lateral declivity of the elytron, barely visible dorsally and well separated from the external edge of the elytron; (3) a narrow central zigzagging band (width in the middle = 0.30 mm, maximum width in the contact zone with the elytral edge = 0.68 mm) located slightly behind the centre of the elytron; this band joins the elytral suture and external edge; (4) two large posterior blotches, obliquely arranged, located in the posterior third of the elytron; the internal elliptical blotch (Ma = 0.62 mm, ma = 0.48 mm) is positioned anterior to the external, almost rounded one (Ma = 0.49 mm, ma = 0.46 mm) and well separated from the elytral edge; and (5) a thin black longitudinal line running through the entire suture and extending through the inner half of the elytral apex, its widest point is just below the scutellum in the area of attachment to the median band. Elytral punctures relatively coarse, subconfluent, dense and uniformly distributed over most of the elytral surface except in the periscutellar and humeral region where they are less dense and smaller. Setation of the elytral surface scarcely perceptible but deciduous and composed of very short yellowish-white hairs, directed vertically or subvertically; suture and elytral margin with a line of longer hairs (approximately two to three times the length of surface hairs), lying backwards.

Mesopleurae without a careniform fold or rim along the anterior margin; setation dense and directed backwards, covering most of the mesopleural surface except along the central zones contiguous to the mesosternum, which are smooth and almost hairless. Mesosternum ( Fig. 4 ) black, shiny and very finely microreticulated, without a modified anterior medial area (scutum or "central shield" sensu Pardo Alcaide 1950, 1954a); slightly elevated at the centre of the anterior edge, with the anterior margins rimmed, forming an open angle; lateral branches of the mesosternum relatively short and narrow; central posterior projection in blunt point between mesocoxae; discal and anterior areas of mesosternum smooth and hairless. Mesosternal punctures fine, scarce, and restricted to mainly the lateral branches and the posterior projection. Setation long, similar to that of the mesopleurae, lying backwards, following the pattern of the punctures in which they are inserted.

Ventral region of the body with black integument, shiny, finely microreticulated, with fine and very dense punctures, subconfluent, hidden under the setation; setation very dense, evenly distributed and longer than that of the pronotum, giving the body a silver appearance except along the narrow mid-longitudinal band of the metasternum, which is smooth and hairless. Last abdominal ventrite with a deep and wide V-shaped central notch in its posterior margin, with a setation much less dense than the rest of the abdominal ventrites.

Legs thin and narrow, with reddish-orange femora and tibiae, somewhat obscured distal ends, brownish-red trochanters that are slightly orange at the ends, black coxae that turn brownish red towards the apex; tarsi, dark brown almost black, except for the first protarsomere and the basal half of the first meso- and metatarsomeres, which are reddish brown; relatively short protarsi (length excluding claws = 1.39 mm), with protarsomere I short and wide, subconical in dorsal view (length, l = 0.30 mm; maximum width, w = 0.22 mm; l/w = 1.36), protarsomeres II (l = 0.22 mm; w = 0.16 mm; l/w = 1.37), III (l = 0.20 mm; w = 0.16 mm; l/w = 1.25) and IV (l = 0.18 mm; w = 0.12 mm; l/w = 1.5) subequal to protarsomere I, although gradually becoming smaller; protarsomere V (l = 0.5 mm; w = 0.14 mm; l/w = 3.57) subcylindrical, narrow and elongated; mesotarsi similar to but slightly more elongated (l = 1.58 mm) than protarsi and with slightly narrower tarsomeres; metatarsi longer and narrower than mesotarsi (l = 2.02 mm), with narrower tarsomeres. Leg punctures very dense and thin, slightly smaller than those on the ventral region of the body; setation whitish yellow, dense and thinner and shorter than that of the ventral region, almost lying on the surface, with the highest density on the tibiae and the inferior side of the femora; internal side of the anterior tibiae with a band of whitish hairs shorter and slightly denser than on the rest of the protibiae, hairs on the distal half of the outer carina slightly more erect and denser than the rest, uniform in size, without longer hairs. External apical end of the protibiae terminates in a small or narrow digitiform expansion almost covered entirely by setation. Tarsi with tarsomeres I to V bearing a small hirsute brush on the underside; on tarsomere V, the brush only occupies the proximal half; hairs on the protarsomeres are exclusively white, while those on the meso- and metatarsomeres are a mixture of white and dark brown. Apical spines of pro- and mesotibiae very small and narrow, subequal, with a blunt tip; apical internal spine of the metatibiae similar to that of the pro- and mesotibiae (length = 0.21 mm), the external one slightly longer and thicker (length = 0.22 mm), subcylindrical, obliquely truncated at the apex, weakly spatulate but slightly widened distally ( Fig. 5 ). Brown to orange claws, curved along the apical two-thirds, with a weak lower basal tooth; upper and lower lobes of similar length, the lower lobe narrower.

Aedeagus ( Fig. 6 A–C ) with narrow and elongated parameres, 1.55 times longer than the phalobase, with a deep and narrow central longitudinal cleft in the apical half in dorsal view; parameral lobes slightly curved, having a digitiform aspect in lateral view and narrow, laminar and acuminate towards the apex in dorsal view. Phalobase slightly widened in dorsal view and narrow in lateral view. Middle lobe narrow, with rounded apex, obliquely truncated in its dorsal-apical region and curved in its proximal half, with two evident teeth in the ventral region, subequal and clearly separated (type isoharpagae sensu Pardo Alcaide 1948, 1950), near but well distanced from the apex. Dorsal-apical hook (uncus sensu Pardo Alcaide 1948, 1950), small, curved at the end, and with a sharp tip. Spiculum gastrale as in Figure 6D .

Female: Similar to the male but differing in the following features: protibiae with a small sharp tooth at the external apical end, with long and fine whitish semi-erect hairs along the outer edge, standing out from the short and lying setation of the surface; external side of the first four protarsomeres with long erect hairs, directed forward, similar to those on the outer edge of the protibiae, which also stand out from the short lying setation; last abdominal ventrite with a posterior margin that is not notched in the middle. Valvifer and stylus as in Figure 7 .

Variability.

Not very marked but present in the following characters: total length, 7.3 to 10.1 mm, mean 8.6 mm (N = 19), males 7.6 to 9.1 mm, mean 8.2 mm (N = 5), females 7.3 to 10.1 mm, mean 8.7 mm (N = 14); maximum width, 2.2 to 3.7 mm, mean 2.8 mm (N = 19), males 2.2 to 2.8 mm, mean 2.6 mm (N = 5); females 2.3 to 3.7 mm, mean 2.9 mm (N = 14); frontal red spot with little variation in diameter and intensity; chromatic pattern of the antennae variable, particularly in the amplitude of the brown coloration: between antennomeres I and V, both inclusive: 26.3% (N = 19) (antennomere I presents a very dark basal region), between antennomeres II and V: 52.6% (sometimes the apical third of antennomere V is black), between II and IV: 5.3%, and between II and III: 15.8%, including the holotype; antennomeres VI–XI always black, although some specimens present a narrow basal brown ring on antennomeres VI and XI; punctures and setation of the head slightly variable in density, especially in the posterior area of the frons and in the vertex, with larger individuals showing greater density; smooth and glabrous pronotal areas that vary to a slight extent; elytral design generally constant, although there is a certain variation in the size of the spots of the anterior and posterior series (in the latter, the two rounded spots are joined in some specimens) and in the thickness of the sinuous median band, which, in some specimens, is interrupted in the middle; the external apical spine of metatibiae in larger specimens is visibly widened in the distal half. No variation is observed in the aedeagus of the studied males.

The coloration of live specimens varies markedly with that of the preserved specimens ( Fig. 1C, D ). Contrasts in the elytral coloration pattern are much more evident in live specimens, especially the ivory tones of the background and the reddish-orange coloration, which remains in only a few of the preserved specimens. In the specimens collected in 2002, the reddish coloration has been completely lost, and the elytra only retain a bicolored appearance with a uniform pale background and black spots and bands.

Etymology.

The word “armass” refers to the Tamazight (Bereber) name of the plant on which C. armass is usually found ( Atriplex halimus ).

Distribution and autoecological notes.

Croscherichia armass is only known from three nearby localities (separated by a maximum distance of about 35 km) in the region of Missour (Boulemane Province, Fès-Boulemane Administrative Region), east of the Eastern Middle Atlas in the valley or middle section of the Muluya River (Oued Moulouya) ( Fig. 2 ): 1. Interior area of ECWP (Missour), 954 m, 33.01191N, 4.09693W. 2. Al Baten 1 (between Missour and Outat el Haj), 830 m, 33.20696N, 3.8697W. 3. Al Baten 2 (between Missour and Outat el Haj), 980 m, 33.16433N, 4.01064W.

The region is dominated by calcareous sedimentary materials: Quaternary alluvial plains with superficial soils. The area is within the mesomediterranean bioclimatic zone ( Michalet 1991) and presents a lower arid ombroclime (mean annual rainfall: 159 mm in Missour, and 153 mm in Outat el Haj) and a marked continentality, particularly during cold winters ( Le Houerou 1989). The habitat of the species’ area of occupation (sensu IUCN 2001) is, in general, steppes with little vegetation. The interior area of the ECWP-Missour) includes mostly open formations known as the Hammada steppes. Typical species occurring in this arid environment include Hammada scoparia (Pomel) Iljin, Launaea arborescens (Batt.) Murb., Atriplex halimus L., Acanthorrhinum ramosissimum (Coss. & Durieu) Rothm., and Echinops spinosissimus Turra, Salsola L. In addition, the species Retama sphaerocarpa (L.) Boiss., Ziziphus lotus (L.) Lam., and Tamarix L. ( Quézel et al. 1994) are found along the wadi courses. The vegetation of the ECWP interior area is in an excellent state of conservation and presents a high level of diversity, mainly due to a perimeter enclosure that isolates it from anthropogenic activities, including livestock grazing. This space can, therefore, be considered as an authentic reserve for the region’s flora and fauna. The Al Baten area (both localities 1 and 2) ( Fig. 1A ) has lower vegetation cover and floristic diversity, and is in a poorer state of conservation, compared with the ECWP, a likely consequence of livestock (sheep and goats) grazing. This area is a steppe on an alluvial flood zone comprised of clay substrates (alluvial plain silt) that, depending on precipitation conditions, is used as a cereal field. Two species predominantly dominate the vegetation in Al Baten: Atriplex halimus L. and Salsola gaetula (Maire) Botsch. The conservation state of the Al Baten 2 vegetation ( Fig. 1A ) is better than that of Al Baten 1, particularly due to the presence of Ziziphus lotus and Halogeton sativus (L.) Moq. bushes.

Live C. armass specimens can be found in flight and actively feeding on flowers of the Chenopodiaceae A. halimus roughly between the hours of 10:00 and 16:00 (UTC). The coloration of C. armass blends in with the inflorescences of A. halimus , which can make locating specimens difficult. Bologna and Coco (1991) did not report Croscherichia feeding on any species of Chenopodiaceae . According to the scarce data available, the active period of C. armass adults is restricted to the end of summer, specifically to mid-September, which coincides with the blooming of A. halimus . Although the phenology of C. armass is not unique for Croscherichia , it is exceptional as only one other species, C. delarouzei , has been recorded as active in September ( Bologna and Coco 1991). Moreover, to date, no other Mylabrini species have been reported as active in late summer in the Missour region. In fact, adults of Mylabrini in this region are only active during spring or, at most, until early summer, coinciding with the main plant flowering period ( François, Ruiz and García-París, pers. obs. and in prep.).

Figures

Figure 1. Habitat and live specimens of Croscherichia armass sp. nov. A thickets of saltbush (Atriplex halimus) in an alluvial silt plain of the Al Baten area between Missour and Outat el Haj B detail of Atriplex halimus L. where the species is usually found. Emirates Center for Wildlife Propagation (ECWP, Missour) C, D active specimen on Atriplex halimus L. (ECWP, Missour). Photographs by AF.

Figure 2. Map of the Missour area in eastern Morocco, showing the type locality of Croscherichia armass sp. nov. (star) and the two other localities where the species occurs (circles).

Figure 3. Holotype of Croscherichia armass sp. nov. A dorsal view B lateral view C frontal view D dorsal view of head and pronotum. Photographs by A. Sanchez-Vialas.

Figure 4. Mesosternum of Croscherichia armass sp. nov. Note the absence of a modified anterior medial area (scutum sensu Pardo Alcaide 1950). Scale bar: 0.5 mm. Drawing by JLR.

Figure 5. Metatibial spurs of Croscherichia armass sp. nov. A ventral view B lateral view. Scale bar: 0.5 mm. Drawing by JLR.

Figure 6. Aedeagus of Croscherichia armass sp. nov. A tegmen, lateral view B tegmen, dorsal view C median lobe, lateral view D spiculum gastrale. Note the narrow and elongate parameres and the middle lobe with two evident teeth in the ventral region that are subequal and clearly separated (type isoharpagae sensu Pardo Alcaide 1948). Scale bar: 0.5 mm. Drawing by JLR.

Figure 7. Valvifer and stylus of Croscherichia armass sp. nov. Scale bar: 0.5 mm. Drawing by JLR.