Trox strandi Balthasar, 1936 was described on an indeterminate number of specimens from the Algerian locality of Sidi-bel-Abbès (loc. typ.), and its author considered it “probably a very rare species” (Balthasar, 1936: 453). One syntype (unsexed specimen; examined by R. Pittino) is preserved in the National Museum of Prague (Czech Republic) (Bezděk & Hájek, 2009), which could be the holotype by monotype (see Zídek, 2013: 17).

Since its description, references to this species are very scarce and its taxonomic status has been controversial. So, Scholtz (1982) considered it an independent species. Pittino (1983) downgraded T. strandi to aberration and synonymized with Trox fabricii Reiche, 1853. Baraud (1985) treated it as separate species and indicated several diagnostic characters, but later relegated it to variety of T. fabricii (Baraud, 1987, following Pittino’s criteria). At the same time, Pittino (1985) included T. strandi as valid species within Trox hispidus (Pontoppidan, 1763)-group, although without argumentation. Subsequently, this author resurrected T. strandi and supported the validity of the species “based on the study of the type and additional material” (not mentioned) (Pittino, 2006a: 26; see also Pittino, 2006b; Zídek, 2013; Pittino & Bezděk, 2016). At last, Pittino (2011) illustrated the aedeagus and prosternal apophysis of T. strandi, and pointed out the differential traits between this species and the other two morphologically closer, T. fabricii, widely distributed throughout North Africa, southern Iberian Peninsula, Sicily (Italy) and Maltese islands, and Trox cyrenaicus Pittino, 2011, whose known distribution is restricted to Benghazi, northeastern Libya (Baraud, 1985, 1992; Ruiz, 1995; López-Colón, 2000; Pittino, 2006b, 2011; Pivotti et al., 2011; Pittino & Bezděk, 2016).

Pittino (1985), Zídek (2013) and Pittino & Bezděk (2016) ascribe T. strandi to the subgenus Trox Fabricius, 1775, but according to Strümpher et al. (2016) Trox is a monotypic genus, based on available phylogenetic evidence.

The only known location for T. strandi is the type-locality, in northeastern Algeria (35°12’N-0°38’O, 470 m, Sidi-bel-Abbès province) (Balthasar, 1936; Baraud, 1985; Pittino, 2011). However, Pittino (2006b) and Pittino & Bezděk (2016) cited it, generically, also from Libya, Tunisia and Morocco, but without providing any precise additional records. No data about its habitat and ecology are available.

During surveys at several stations in the Oriental and Fes-Boulemane administrative regions, carried out within the framework of various projects on the entomological diversity of arid lands from Eastern Morocco, supported by the Emirates Center for Wildlife Propagation (ECWP), two specimens of T. strandi were collected in as many relatively nearby locations (about 70 km). These are the first precise records for Moroccan territory and extend the known distribution range of the species about 450 km to the southwest (Fig. 1). Specimens were identified according to morphological traits pointed out by Balthasar (1936), Baraud (1985) and Pittino (2011), and confirmed with the examination of male genitalia. Likewise, T. strandi specimens were compared with abundant material of T. fabricii (the morphologically closest species) from Morocco and the Iberian Peninsula (Appendix 1).

Material examined of T. strandi: MOROCCO: 1 ♂, 32°49’52’’N-4°24’19’’W, 1043 m, Ksabi (province of Boulemane, Fes-Boulemane administrative Region), 17-VIII-2017, C. Belamime leg. (in col. Emirates Center for Wildlife Propagation, Missour, Morocco); 1 ♀, 32°28’05’’N-3°37’41’’W, 1750 m, Tameslemt (province of Boulemane, Fes-Boulemane administrative Region), 25-III-2012, A. François & F. Soldati leg. (in col. Emirates Center for Wildlife Propagation, Missour, Morocco).

Tameslemt is found in the north foothills of the Eastern High Atlas mountain range and Ksabi in the upper basin of the Moulouya river. The bioclimate is semi-arid with cold winters in the first station (annual average rainfall: 400–500 mm) and arid with cold winters in the second (annual average rainfall: 100–200 mm), with high continentality in both of them (see Sauvage, 1963; Le Houérou, 1989). In the type-locality, the bioclimate is semi-arid with cold winters (annual average rainfall: 395 mm) (Le Houérou, 1989).

The location of Tameslemt (Fig. 2) is a loosely open wood of juniper trees [Juniperus oxycedrus L. and Juniperus phoenicea L. subsp. turbinata (Guss.) Nyman], that is characteristic of the cold subunit of the semi-arid bioclimate (Emberger, 1950), with a grazed steppe of Macrochloa tenacissima (L.) Kunth, 1829, Rosmarinus officinalis L., 1753, and Artemisia L., 1753. The specimen was found below a stone. At Ksabi, the vegetation around the village is also a grazed steppe but mostly covered by plants of the Chenopodiaceae family. There, near the Moulouya river, the lower level of the plain is characterised by great formations of Hammada scoparia (Pomel) Iljin, favoured by very dry conditions or high grazing pressure (Pujos, 1955; Defaut, 2015). At this location, the specimen was collected manually in a compost pile, in the center of the village, near irrigated fields.

Trox strandi is morphologically similar to T. fabricii and both differ mainly in the following characters (Baraud, 1985; Pittino, 2011; J.L. Ruiz & A. François, pers. obs.): T. strandi presents subequal tubercles on both odd and even elytral inter-striae (tubercles on even inter-striae usually between 1/2–3/4 smaller than those on the odd, some even of equal size), little and equally convex in all inter-striae, sub-rounded; third inter-stria barely elevated at its base, without alignment of confluent tubercles, not costiform at this level; striae almost straight; even costae just wider than odd and elytral profile uniformly convex dorsally in lateral view with the greatest height at about middle. In contrast, T. fabricii shows tubercles on odd elytral costae clearly larger than those on even costae, usually markedly convex, subovoid and elongated (however, elytral sculpture of this species is highly variable); third inter-stria strongly elevated, subcostiform, at its base, with an alignment of confluent elongated tubercles at this level; striae more sinuous; even costae distinctly wider than odd and, in general, dorsal elytral profile basally flat with the greatest convexity clearly behind middle [this last feature, referred by Pittino (2011), is variable and difficult to weight in some specimens; pers. obs.]. Besides, the prosternal process is different in both species and the male genitalia shows slight differences (see Pittino, 2011: p. 378, figs. 7–8, p. 379, figs. 13–16). In addition, the Moroccan specimens of T. strandi present the body tegument matte, even in specimens without almost integumentary wear, while in T. fabricii it is clearly brighter; nevertheless, this character and the morphology of prosternal process are difficult to evaluate in old specimens, due to the remarkable wearing because of the strong fossorial activity of Trox species (Pittino, 2011; pers. obs.). Likewise, we have observed a high inter- and intrapopulation variability on the prosternal apophysis morphology in T. fabricii, which leads us to consider with caution the diagnostic value of this character.

To illustrate the interpopulation variability of the species, images of the habitus, aedeagus (male) and prosternal process (female) of the Moroccan specimens are provided (Figs. 3–5). Likewise, the genital palpi of T. strandi female, compared with those of T. fabricii, are illustrated (Fig. 6).The length of the studied exemplars ranges from 9.3 mm (♂) – 8.9 mm (♀) (7.5 mm, according to Balthasar, 1936 and Baraud, 1985).

In view of the new Moroccan locations of T. strandi and its morphological similarity with T. fabricii, it would be interesting to carry out a critical review of the records of the latter species, at least, from eastern Morocco (e.g. Martínez de la Escalera, 1914; Kocher, 1953, 1958; Pardo Alcaide, 1955; Baraud, 1985; Palmer et al., 1999), in order to delimit the area of occupancy (sensu IUCN, 2001) of both taxa in this country.