Anthaxia (Haplanthaxia) cadusiana, Baiocchi, Daniele, 2015

Baiocchi, Daniele, 2015, A revision of the Anthaxia (Haplanthaxia) schah Abeille de Perrin, 1904 species-group, with description of two new species from Iran (Coleoptera: Buprestidae: Anthaxiini), Zootaxa 3918 (1), pp. 57-91 : 58-62

publication ID

https://doi.org/ 10.11646/zootaxa.3918.1.3

publication LSID

lsid:zoobank.org:pub:402C6EEE-4E42-45C2-8A02-87BDDC1EFF34

DOI

https://doi.org/10.5281/zenodo.6121261

persistent identifier

https://treatment.plazi.org/id/F420A31D-FFDC-4E10-3E8D-F98E129E29B1

treatment provided by

Plazi

scientific name

Anthaxia (Haplanthaxia) cadusiana
status

 

The Anthaxia (Haplanthaxia) schah Abeille View in CoL de Perrin, 1904 species-group

Definition of the species-group. Small to medium size species; length: 3.1–6.2 mm, width: 1.2–2.3 mm, length to width ratio: 2.6–3.0 times longer than wide; body subparallel ( Fig. 31 View FIGURES 29 – 32 ) to slightly wedge-shaped ( Fig. 13 View FIGURES 13 – 16 ); dorsal side moderately convex, ventral side strongly convex; dorsal pubescence short and inconspicuous; ventral and leg pubescence pale, of average length, well developed on ventral pronotal surface. Dorsal colouration dark bronze, reddish-greenish bronze, completely bluish-green, or bright emerald green with golden, reddish, or purple tinge on elytra, occasionally with rather silky lustre; pronotum always showing two more or less distinct, variably sized maculae; ventral colouration usually of the same dorsal basal color.

Head small, never wider than anterior pronotal margin; eyes long, widest in lower 1/2, occasionally slightly projecting beyond outline of head; frons ( Fig. 33–42 View FIGURES 33 – 38 View FIGURES 39 – 44 ) moderately narrow, 0.5–0.65 the width of head, subparallel, slightly convex to fairly bilobate; vertex flat or feebly vaulted, 0.35–0.5 the width of head; inner ocular margins mostly very slightly s-shaped, feebly converging on the vertex; clypeus short, flat to slightly prominent, lateral clypeal margins subparallel, anterior margin weakly to deeply emarginate; sculpture of head inconsistent, variable even within a same species, usually shallow, areolate to subfoveate, usually consisting of a tight network of well defined subpolygonal cells with narrow borders on the upper part of the head, as in A. (H.) cadusiana sp. nov. ( Figs. 41, 42 View FIGURES 39 – 44 ), and of subrounded, oblong foveae, with interspaces smooth to finely microsculptured on the lower part, as in A. (H.) elamita sp. nov. ( Figs. 33, 34 View FIGURES 33 – 38 ); cell bottom mostly microsculptured with a variously shaped setigerous pore; frontal pubescence mostly yellowish, short and thick in males, very short and inconspicuous in females.

Antennae ( Figs. 45–54 View FIGURES 45 - 59 ) rather flattened, slightly longer than pronotal length in midline in males, distinctly shorter in females; antennomeres 3–10 subtriangular to subtrapezoidal, slightly wider than long (except in A. (H.) elamita sp. nov., that has strongly modified antennomeres).

Pronotum slightly transverse, 1.3–1.5 times wider than long, strongly convex and widest in anterior 1/2; lateral margins regularly arched in anterior 1/2, slightly to strongly sinuate on posterior 1/2; posterior angles right to slightly acute; anterior pronotal margin very slightly bilobate, with central lobe feebly pronounced, occasionally absent; posterior margin slightly arched backward in middle; lateroposterior depressions rather transverse, moderately deep to very shallow, barely developed in some specimens; pronotal sculpture constant, areolate in all species, consisting of irregular polygonal cells homogeneusly distributed over the whole surface, more shallow on mid discal area; cell borders well raised; cell bottom brilliant, smooth, or slightly rugose to finely microreticulate, with variable setigerous pore, from small grain to tiny pores; pronotal pubescence very short and recumbent, thin, colourless and hardly visible.

Scutellum of variable shape, subpentagonal to subcordiform, finely microsculptured.

Elytra 2.0–2.4 times longer than wide, rather convex, slightly narrowed posterior to humeral swelling, leaving lateral abdominal margins visible; elytral base as wide as posterior pronotal margin with anterolateral angles well defined, occasionally somewhat sharp ( Fig. 27 View FIGURES 25 – 28 ); basal transverse depressions shallow to moderately deep, nearly reaching scutellum; humeral swellings weakly to moderately developed; lateral elytral groove flat, very narrow, wider in apical 1/3, ending before the apex; lateral elytral margins weakly serrate in apical 1/3; elytral apices distinctly sloped, deeply serrate, separately and mostly rather angularly rounded; epipleura narrowed and distinctly serrate before mid length, parallel on posterior 1/2, disappearing at the apex; elytral sculpture dense, homogenous, very finely imbricate-punctulate, sometimes with silky appearance or slightly plicate longitudinally ( Fig. 19 View FIGURES 17 – 20 ); pubescence erect, colourless and inconspicuous, short, noticeable only at high magnification.

Ventral surface. Central metasternal suture with posterior end always distinctly and widely open, with moderately raised borders; proepisternal sculpture shallow, areolate or densely foveolate, consisting of cells with a smoothly microsculptured bottom and tiny setigerous pore; ventral abdominal surface with remnants of areolate sculpture and very fine basal microreticulation, more distinct on the smooth posterior margins of each ventrite; sculpture of legs very finely imbricate; protrochanters of both sexes always bearing a spine, strongly acute in males, less developed to almost absent in females, meso- and metatrochanters smooth.

Anal ventrite apically subround or subtruncate in males, more acute in females; posterior 1/2 widely depressed along the margin, somewhat raised in middle, serrate laterally; apex variously notched in all females and in males of A. (H.) elamita sp. nov. and A. (H.) cadusiana sp. nov.

Legs of average length, rather slender; protibiae slightly incurved inward, with inner margin usually densely pubescent, slightly carinate externally, sometimes with irregular and distinctly rough edges; meso-tibiae mostly straight with outer margin occasionally very rough, with base of bristles strongly raised; metatibiae ( Figs. 55–59 View FIGURES 45 - 59 ) strongly flattened, with distal part of outer margin bordered by stout dark bristles; inner margin of meso- and metatibiae completely smooth, slightly sinuate, distinctly curved inward on distal part, bearing a series of short, dark, widely spaced hispid bristles and a strong, subtriangular apical spur; tarsomeres narrow, with weakly curved tarsal claws of average length, except in A. (H.) naviauxi that has somewhat wider tarsomeres and long tarsal claws.

Aedeagus. Tegmen 4.5–7.0 times longer than wide, fusiform ( Fig. 75 View FIGURES 70 – 79 ) to subparallel ( Fig. 76 View FIGURES 70 – 79 ), subcylindrical basally, with lateral parameres usually slightly wider and more chitinous at mid length, apical part flattened, subparallel or slightly narrowed, acutely pointed; membranaceous setigerous area rather extensive, located along the finely crenulate pre-apical lateral margin; median lobe ( Figs. 70–74 View FIGURES 70 – 79 ) narrow, subparallel to slightly wider basally, approximately 10 times longer than wide, moderately convex dorsally, finely microsculptured, rarely very finely crenulate laterally; apex smooth, subtriangular or lanceolate, strongly acute; basal apodemes thin and long, sometimes sinuate, representing about 1/3 of the total length.

Sexual dimorphism. Females differ from males mainly in their stouter and subparallel body, frons slightly to distinctly wider than in males, with shorter and finer pubescence, shorter antennae with less enlarged antennomeres, protrochanters more obtusely spiny, and inner margin of meso- and metatibiae less incurved, with a weaker or missing apical spur. Sexual difference in the shape of the anal ventrite is present in A. (H.) naviauxi , A. (H.) schah and A. (H.) wethloi . Sexual dichromatism usually very slight or absent, but males of A. (H.) wethloi may show a green colouration of the frons, while in A. (H.) naviauxi , based on the scarce available material, males show more golden greenish-red dorsal lustre ( Figs. 7 View FIGURES 7 – 12 , 21 View FIGURES 21 – 24 ), and the two sexes are strongly dichromatic ventrally ( Figs. 22, 24 View FIGURES 21 – 24 ).

Remarks. The extensive and careful examination of the taxa treated in this study, led me to notice that along with the above-mentioned convergence of various characters, each species shows also an obvious degree of intraspecific variability, in colouration as in morphological characters ( Figs. 86–94 View FIGURES 86 – 94 ).

As already stated above, this variability was considered seriously, and a first examination of many specimens of A. (H.) wethloi and A. (H.) schah , including comparison of the respective types, initially made me have doubts about their current specific separation. In spite of their strongly different habitus, these two taxa show an almost complete overlap in external morphological characters that made me think they might be two well defined phenotypes of the same species, resulting from a process of adaptation to different ecological niches in different environments.

My doubts came from the fact that I usually do not judge mere difference of colouration as a sufficient reason to justify specific separation, although there are cases in which I consider that the overall colouration of well defined populations of a same species, which appear to be so consistently different and homogenous to be worthy of consideration and valued at least at a subspecific level.

Nevertheless, the current absence of specimens with obvious regressive or transitional patterns of colouration, and the fact that the two forms have never been observed to occur together in a same locality, induced me to study more deeply the specimens and further critically examine their morphology. This eventually led me to find a slight but substantial difference in the genitalia of both species. Besides their different habitus, a slight sexual difference in the width of the frons of females ( Figs. 36, 38 View FIGURES 33 – 38 ) and in the genitalia of both sexes, appear to be the only differences on which their specific separation can be based. I observed that, compared to A. (H.) schah , the female's ovipositor of A. (H.) wethloi shows a proportionally larger surface of the pre-apical lateral flap-like folds, and a slightly more pronounced styli-bearing apical process ( Figs. 81, 82 View FIGURES 80 – 85 ). With regard to the male genitalia, in A. (H.) wethloi the tegmen is proportionally slightly longer and more slender ( Figs. 76, 77 View FIGURES 70 – 79 ), and the apex of the median lobe ( Figs. 71, 72 View FIGURES 70 – 79 ) shows a slightly wider conformation in the pre-apical part of the ventral lamella; the inner laminal sclerifications also usually seem to be more pronounced. Hence, on the basis of these slight characters only, and in consideration of the evident closeness between species of this new group, I continue to regard A. (H.) schah and A. (H.) wethloi as two different species.

The reasons that led to the recognition of this interesting new group, can be summarized in the following combination of characters, always present and consistent in each of the five species:

- head never wider than anterior pronotal margin

- frons moderately narrow (0.5–0.65 times as wide as width of head) with inner ocular margins subparallel ( Fig. 41 View FIGURES 39 – 44 ) to feebly s-shaped ( Fig. 33 View FIGURES 33 – 38 )

- sculpture of pronotum homogenously areolate, never stretched or striated, consisting of irregular polygonal cells mostly with well raised borders and central or eccentric grain

- inner margin of male meso- and metatibiae always weakly sinuate or straight, never serrate, with scarce pubescence consisting of few short and hispid dark bristles rather widely spaced, in contrast with the normal pubescent protibiae; apices somewhat flared, with a strong inward protruding spur in males ( Figs. 55–59 View FIGURES 45 - 59 )

- protrochanters always bearing a strong spine, sharply acute in males ( Fig. 43 View FIGURES 39 – 44 ), more obtuse in females ( Fig. 44 View FIGURES 39 – 44 ); meso- and metatrochanters always smooth.

A. (H.) schah species-group A. (H.) angustipennis species-group

Dorsal colouration reddish-copper to dark bronze, or Dorsal colouration copper-brown to dark bronze, rarely with completely green, or green with golden to reddish-purple greenish tinge as in some specimens of A. (H.) angustipennis tinge on elytra; pronotum always with more or less distinct, (Klug, 1829) and A. (H.) robusticornis Bílý, 1990 ; dark variously expanded dark maculae pronotal maculae rarely present (observed only in A. (H.)

holynskii Bílý, 1990)

Antennae of males usually slightly longer than pronotal Antennae of males shorter, or at most as long as pronotal length in midline, consisting of slender and flatter, length in midline, consisting of thicker and strongly transverse, moderately transverse antennomeres (except in A. (H.) more compact, enlarged antennomeres elamita sp. nov. that shows strongly modified antennae)

Pronotal sculpture areolate, always homogenously polygonal Pronotal sculpture usually regularly polygonal on the whole on the whole pronotal surface in all species surface, rarely longitudinally stretched on discal area (as in A. (H.) tanjorensis Obenberger, 1938 ), or rather confused (as in A. (H.) robusticornis Bílý, 1990 )

Elytra subparallel or slightly wedge-shaped, always weakly Elytra distinctly wedge-shaped and strongly narrowed at mid narrowed at mid length; elytral apices separate and rather length; elytral apices always separately and regularly rounded angulated (except in A. (H.) naviauxi which has separately

and regularly rounded elytral apices)

Legs proportionally slightly longer and slender, tarsomeres Legs proportionally slightly shorter and somewhat stouter; narrow, with rather short and slender tarsal claws (except in tarsomeres slightly stouter and compact, with stouter tarsal A. (H.) naviauxi which shows more developed tarsomeres claws

and claws)

Inner margin of meso- and metatibiae never serrate, rather Meso- and metatibiae straighter, usually with inner margin bent inward distally, with strong, single, apical spur more widely to only apically serrate; apical inner spur usually evident in males consisting of a multitoothed outgrowth

Protrochanters always with spine Protrochanters always smooth

Posterior end of metasternal suture, shortly and narrowly Posterior end of metasternal suture, shortly and widely open, open, with borders distinctly raised with flat borders

Anal ventrite of males distinctly notched in two species Anal ventrite of males never notched

Sexual dichromatism usually absent (rarely present in Sexual dichromatism usually present only in the colouration of colouration of frons and ventral side of bronze species) frons

Aedeagus subparallel to slightly fusiform, with parameres Aedeagus always spindle- or bottle-shaped, with thicker slightly widened at mid length, more flattened and rather parameres, usually sinuately narrowed on apical part straightly tapered on apical part

This last mentioned character, namely the presence of a spine on the trochanter on the forelegs of females, is particularly unusual and apparently unique. According to Bílý (pers. comm.), it is a character which is never present in females of palaearctic Anthaxia , and more frequently seen in Indo-oriental species.

Among other interesting characters, not always present in all species of this group, is the unusually strong development of the antennomeres in males of A. (H.) elamita sp. nov. ( Fig. 45 View FIGURES 45 - 59 ), which in some specimens reaches a level of development that I have never observed in any other palaearctic species of the subgenus Haplanthaxia Reitter, 1911 and is usually found only in some representatives of the subgenus Cratomerus Solier, 1833 . A further unusual feature shown by males of this same species is the presence of an apical notch in the anal ventrite ( Fig. 60 View FIGURES 60 – 69 ).

This character, rarely encountered in males of Anthaxia , is present also in males of A. (H.) cadusiana sp. nov. ( Fig. 66 View FIGURES 60 – 69 ), a recently reared male of which ( Fig. 91 View FIGURES 86 – 94 ) shows a coppery regressive colouration so similar to that of A. (H.) wethloi ( Fig. 94 View FIGURES 86 – 94 ), to be distinguished from the latter only by the presence of a deep notch in the anal ventrite.

With regard to colouration, personal field observations led me to notice that species showing a copper-bronze habitus, namely A. (H.) naviauxi and A. (H.) wethloi , are mostly found in dry rocky habitats, while the remaining species, with a variable basic green colouration, live in habitats with a more green and grassy vegetation cover.

Adults are flower visitors, and the larvae, rather polyphagous, develop in a wide spectrum of Angiosperms. Apart some highly distinguishing traits, their strong morphological closeness suggests that species of this group might have differentiated in relatively recent times. Their limited distribution is also indicative of this, since this group is mostly comprised of endemic Iranian species, the only exceptions being a couple of records of A. (H.) schah from Syria and Iraq. The species-group is distributed from the northeastern Syrian desert, and probably northern Iraq, eastward through the Zagros range, to the sub-Caspian Elburs range and the southeastern Iranian province of Kerman, while in the hot coastal areas of the Persian Gulf they are apparently replaced by species of the A. (H.) angustipennis species-group. Records from southern Caucasus and eastern Turkey need confirmation, and at present, none of the five species has ever been reported from Turkmenistan, Afghanistan or Pakistan, though it is possible that the species-group may occur in these countries that partly share similar habitats with Iran.

According to its current Turano-Syrian distributional pattern, the group can objectively be included in the Turanian chorotype ( Vigna Taglianti et al. 1999 ).

The various species treated in this study are usually absent in collections, or at most poorly represented, even in those of the main specialists of Buprestidae . Considering the large amount of material collected by a number of entomologists who have visited the Middle East in the last decades, such scarcity of material is probably due to actual rarity in nature. On the other hand, during the fieldwork that I have carried out in Iran since the year 2005, A. (H.) wethloi and A. (H.) schah have proved to be more widely distributed than previously thought, and sometimes relatively common locally, though still rather elusive.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Buprestidae

Genus

Anthaxia

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