Chikatunolepta, Bezděk, 2020

Bezděk, Jan, 2020, Chikatunolepta n. gen. - a new genus of Saharo-Arabian Monoleptites (Coleoptera: Chrysomelidae: Galerucinae), Israel Journal of Entomology (Oxford, England) 50 (2), pp. 11-29 : 12-17

Genus Chikatunolepta n. gen.

LSID: urn:lsid:zoobank.org:act:D7A8D880-E5C6-4C8F-AFFF-EEDF2A7485BF .

Type species: Calomicrus buettikeri Medvedev, 1996 , designated here.

Etymology: The genus is named after Prof. Vladimir Chikatunov, a coleopterist at the Steinhardt Museum of Natural History, Tel Aviv, Israel, and Monolepta , a well known genus in Monoleptites. Feminine gender.

Description: Small species (3.3–4.7 mm). Body completely yellow or pale brown, except black extreme base of basimetatarsomere, elytra sometimes with poorly defined brownish pattern ( Figs 1–6). Very extreme lateral margin of epipleura in anterior quarter brown to black.

Male. Labrum transverse with straight anterior margin and rounded anterior angles, surface with several pores bearing long seta. Anterior part of head with triangular elevation, its posterior process forming narrow nasal keel. Interantennal space as wide as antennal insertion. Eyes large. Frons narrow, 1.00–1.20× as wide as diameter of eye. Antennae filiform, 0.80–0.90× as long as body, antennomeres II and III subequal (III 1.00–1.15× longer than II), IV–X long, 3.40–3.80× as long as wide.

Pronotum glabrous, lustrous, 1.25–1.40× as wide as long, widest in middle, slightly convex, surface covered with very small punctures and sometimes with traces of indistinct transverse impressions.Anterior margin straight or nearly straight, lateral margins slightly rounded, posterior margin widely rounded.Anterior margin unbordered, lateral and posterior margins thinly bordered.Anterior angles swollen, posterior angles obtusangulate, all angles with setigerous pore bearing long seta. Scutellum small, subtriangular.

Elytra subparallel, relatively flat, almost glabrous (with very sparse setae on lateral and apical slopes), 0.65–0.70× as long as body, 1.50–1.75× as long as wide at humeral part, densely covered with fine confused punctures. Humeral calli developed. Epipleura almost impunctate, glabrous, wide in anterior half, narrowed before elytral midlength, then very narrow and disappearing towards apex. Basal part of epipleura slightly impressed. Macropterous.

Anterior coxal cavities semiopen posteriorly ( Fig. 51). Prosternal process very thin and elevated between procoxae. Abdominal ventrite III (or ventrites II and III) with median processes covered with long setae in middle part, V with two long narrow incisions ( Figs 13–15, 25–27, 37–39). Protarsomere I slightly enlarged. Mesofemora robust with posterior margin slightly emarginate in apical third ( Fig. 49), mesotibiae bent (in Ch. buettikeri also with vertical subapical lamella), mesotarsomere I enlarged. Metatarsomeres I very long, 7.50–8.00× as long as broad ( Fig. 50). All tibiae with apical spur. Claws appendiculate.

Male genitalia. Aedeagus long and narrow, 8.50–9.80× as long as wide, ventral side with elongate apical cavity, basal two-thirds with distinct groove, narrow basally, gradually divergent anteriorly ( Figs 22–24, 34–36, 46–48). Internal sac with sclerite complex containing larger curved basal sclerite fringed anteriorly and bare basally, and pair of very small winged-like sclerites anteriorly ( Figs 7–12).

Female. Mid legs and abdomen not modified. Pro- and mesotarsomeres I not enlarged, narrow and parallel. Last abdominal ventrite entire, without incisions. Spermatheca with elongate nodulus covered with traces of transverse wrinkles, nodulus and cornu gradually connected, cornu C-shaped, apex of cornu with long bent thin appendix, spermathecal duct S-shaped, wide basally and then gradually narrowed ( Figs 17, 29, 41). Bursa sclerites star-shaped, composed of two connected plates ( Figs 18, 30, 42). Sternite VIII suboval, posterior margin with short setae, tignum very long, slender ( Figs 16, 28, 40). Gonocoxae with apices bearing long setae, basal part of gonocoxae forming two wing-shaped plates separated by deep incision ( Figs 19, 31, 43).

Comparison: The representatives of Chikatunolepta n. gen. have very long basimetatarsus with black extreme base, subequal antennomeres II and III, head with large eyes and interocular space as wide as or slightly wider than transverse diameter of eye, large pronotum, mid legs with enlarged femora, modified tibiae and enlarged mesotarsomere I, male abdomen modified, and long narrow aedeagus. Such combination of characters is unknown in any other genus of Monoleptites.

The Monoleptites fauna of the Arabian Peninsula includes five species of Monolepta Chevrolat, 1836 , three species of Calomicrus , one species of Galerudolphia Hincks, 1949 , and one species of Afromaculepta Hasenkamp & Wagner, 2010 .

The Afrotropical genus Galerudolphia was revised by Bolz and Wagner (2005). One of the species, G. arabica ( Medvedev, 1996) , is distributed in Saudi Arabia and Yemen ( Medvedev 1996; Bolz & Wagner 2005; Bezděk 2012). Galerudolphia species can be distiguished from Chikatunolepta n. gen. as follows: pronotum convergent anteriorly, trapezoidal; antennomere III always longer than II; anterior coxal cavities closed; mid legs not modified in males, abdomen not modified in males, aedeagus with incised apex, spermatheca with barrel-like nodulus and short right-angled cornu without appendix. The same characters in Chikatunolepta n. gen.: pronotum subquadrangular; antennomeres II and III subequal; anterior coxal cavities semiopen; mid legs and abdomen modified in males, aedeagus without incised apex, spermatheca with elongate nodulus gradually connected with C-shaped cornu, cornu terminated with long bent appendix.

Another Afrotropical genus Afromaculepta comprises six species ( Hasenkamp & Wagner 2000). One of them, a very widely distributed A. decemmaculata (Jacoby, 1886) , penetrates into Yemen (Beenen 2010, 2019; Bezděk 2012). The genus Afromaculepta is characterised by a yellow body with a black vertex, antennae (except basal antennomeres) and spots on elytra, unmodified abdomen in males, and closed anterior coxal cavities (these characters also distinguish Afromaculepta from Chikatunolepta n. gen.). The structure of the spermateca is very similar to that of Chikatunolepta n. gen.

Monolepta species from the Arabian Peninsula were recently revised by Schlich and Wagner (2010) with four recognized species.An additional species, Monolepta syriaca (Weise, 1924) from Turkey, Syria and Israel was transferred from Calomicrus by Bezděk (2018). In habitus and coloration, Monolepta syriaca and M. saudica Medvedev, 1996 are similar to Chikatunolepta species. Monolepta differs from Chikatunolepta n. gen. in having the mid legs and abdomen unmodified in males, anterior coxal cavities closed, shorter and wider aedeagus with different and more complicated structure of internal sclerites, and the spermatheca with a globular or subglobular nodulus well separated from the cornu.

Chikatunolepta n. gen. is habitually similar also to some species currently classified in the genus Calomicrus . However, the Palaearctic genus Calomicrus is evidently polyphyletic in the current concept and awaits a comprehensive revision. Many yellow Calomicrus species from arid areas of the Mediterranean, Near East and Arabian Peninsula show the habitual affinity to the genus Monolepta and their position in Calomicrus needs revision. There are three yellow Calomicrus species distributed in the Arabian Peninsula: C. arabicus Lopatin & Nesterova, 2006 from the United Arab Emirates and Oman, C. vanharteni Lopatin, 2001 from Yemen, and C. ophthalmicus (Ogloblin, 1936) from Afghanistan, Iran, Oman and Saudi Arabia. All three species have Monolepta -like structure of metatarsomere I (very long with black base) and unmodified male abdomen. I envisage future transfer of them to Monolepta , but such an act needs more comprehensive study exceeding the present one.

Additional genera Nymphius Weise, 1900 , Luperus Geoffroy, 1762 , and Euluperus Weise, 1886 marginally penetrate into the Levant and Near East from the north. These genera have a shorter and wider metatarsomere I without a black base, and a generally black or metallic body. The differentiation characters for these genera were summarized by Bezděk (2015). The species transferred here to Chikatunolepta n. gen. were previously classified in Nymphius Weise, 1900 . The latter genus with five species and two subspecies distributed in Turkey, Caucasus, Bulgaria, Iran, Syria and Israel, is characterized by metallic green or green-blue coloration, a strongly modified male abdomen and a relatively robust aedeagus. The Nymphius species have been recently reviewed by Bezděk (2008).

When compared with the identification key to the genera of afrotropical Monoleptites (e.g. Wagner 2007), Chikatunolepta n. gen. runs to couplets 4–5 (non-metallic species with subequal antennomeres II and III – genera Monolepta , Afromaculepta Hasenkamp & Wagner, 2010 and Afronaumannia Steiner & Wagner, 2005 ). The characters distinguishing Monolepta and Afromaculepta are discussed above. Afronaumannia includes five afrotropical species and differs from Chikatunolepta n. gen. by subtrapezoidal pronotum, antennomere III longer than II, not modified male abdomen, and different structure of aedeagus and its internal sclerites ( Steiner & Wagner 2005).