Hercostomus canariensis Santos Abreu, 1929

Grichanov, I. Ya., Nourti, M. & Kettani, K., 2020, The Hercostomus exarticulatus species group in the Palaearctic Region (Diptera: Dolichopodidae), Caucasian Entomological Bulletin (Caucas. entomol. bull.) 16 (1), pp. 27-34 : 31

Hercostomus canariensis Santos Abreu, 1929

( Figs 9–15 )

Hercostomus canariensis Santos Abreu, 1929: 386 ; Frey, 1936: 70 (as? var. of Hercostomus exarticulatus ).

Hercostomus canariensis var. femoratus Santos Abreu, 1929: 389 (type locality: Spain, Canary Is., La Palma).

Hercostomus canariensis femoratus Santos Abreu, 1929: 389 ; Negrobov, 1991: 83 (unavailable name according to the International Code of Zoological Nomenclature [1999], article 45.6.4.1, as published after 1980).

Hercostomus aff. exarticulatoides: Nourti et al., 2019: 123 (misidentification).

Material. 2♂, 1♀ ( ZIN), Morocco, Rif , Akchour env., Pont de Dieu (river), 35°13ʹ42″N / 5°10ʹ31″W, 536 m, 1.07.2019 (M. Nourti, I. Grichanov) .

Diagnosis. Fore coxa and femora light yellow; hind tibia entirely yellow; hind tibia with strongly sclerotized ovate dorsolateral apical projection; hypandrium with outer arm concealed, more or less straight, weakly curved at apex, and with inner arm trapezoid, strongly projected distoventrally; cercus yellow, dark at apex.

Notes. The wordy description of H. canariensis by Santos Abreu [1929] contains mainly qualitative features being common for all species of the exarticulatus group. A broad shining black tooth between male tibia and tarsus is the most striking key character provided by Santos Abreu [1929: 384] to distinguish his species from H. exarticulatus . This character allows us associating our Moroccan material with H. canariensis . In fact, males of the latter species possess apical projection of hind tibia and basal spine of hind basitarsus, both strongly scletotized and relatively broad, shining black, forming peculiar hitching lock between tibia and basitarsus. Hercostomus exarticulatus and H. exarticulatoides males have the same hitching lock, but with differently shaped and coloured teeth or spines being also weaker sclerotized. Santos Abreu [1929] noted a variety of his new species with partly black fore and hind femora (femoratus). Specimens of this variety belong highly likely to H. exarticulatus .

Ecological notes. The Moroccan material has been collected during joint field trips of all authors of this paper in July 2019 to the Rif Mountains. The God’s Bridge (or Pont de Dieu in French) is an impressive rock arch, located in the north of Morocco, in the heart of Talassemtane National Park; it has a height of 25 m above the river, Oued Farda, which eroded the rock until to form this natural work of art. This station is characterized by clear, fresh and fast-flowing water. The substrate is formed essentially of coarse formations such as gravel and blocks. Adults of H. canariensis have been found resting on large wet stones within stream and grasped from their surfaces by use of plastic pots. This site is part of the subhumid bioclimatic thermomediterranean zone, where vegetation is mainly organised by Quercus rotundifolia, Tetraclinis articulata and Pinus halepensis. The riparian vegetation is very dense, represented essentially by Nerium oleander and Pistacia lentiscus. The vegetal cover of the area and its richness in aquatic resources have established a significant bryological diversity that grows on the rocks.

Distribution. Type locality: Spain, Canary Is., La Palma. Palaearctic: Spain (Canary Is.). First record from Morocco.

Figures

Figs 9–15. Hercostomus canariensis Santos Abreu, 1929. 9 – habitus; 10 – head; 11 – wing; 12 – mid femur; 13 – hitching lock between hind tibia and basitarsus; 14 – hypopygium, ventral view; 15 – apex of hypopygium, lateral view. Рис. 9–15. Hercostomus canariensis Santos Abreu, 1929. 9 – общий виΑ; 10 – гоΛова; 11 – крыΛо; 12 – среΑнее беΑро; 13 – сцепΛение заΑней гоΛени и Λапки; 14 – гипопигий; виΑ снизу; 15 – вершина гипопигия, виΑ сбоку.