Andrena (Truncandrena) alchata Warncke, 1974

Wood, Thomas James, Michez, Denis, Cejas, Diego, Lhomme, Patrick & Rasmont, Pierre, 2020, An update and revision of the Andrena fauna of Morocco (Hymenoptera, Apoidea, Andrenidae) with the description of eleven new North African species, ZooKeys 974, pp. 31-92 : 31

Andrena (Truncandrena) alchata Warncke, 1974

Material examined.

Andrena alchata : Algeria: Maison Carrée, Alger, 1♂, leg. Dr. J. Bequaert, OÖLM (holotype); Andrena doursana agadira : Morocco: S-Marokko, Agadir, 20.ii.1977, 1♀, OÖLM (holotype); Andrena doursana citreola Warncke, 1975: Spain: Vaciamadrid, 25.v.1919, 1♀, leg. Dusmet, OÖLM (holotype); Morocco: Azrou Ras el Ma, 30.iii.1923, 1♀, leg. Schulthess, OÖLM (paratype); Rez Dj. Zalagh, 25.iii.1923, 1♂, leg. Schulthess, OÖLM (paratype).

New material.

Andrena alchata : Morocco: Fès-Meknès, Laanoucer, 33.6167, -4.7489, 2.v.2018, 1♂, 3♀, leg P. Lhomme & A. Sentil; 33.6708, -4.8527, 2-3.v.2018, 1♀, white pan trap, leg P. Lhomme & A. Sentil; 33.6699, -4.8673, 10-11.v.2018, 1♂, 1♀, yellow pan trap, leg P. Lhomme & O. Ihsane; 33.7099, -4.8431, 15-16.v.2018, 1♀, white pan trap, leg. P. Lhomme & O. Ihsane; 7099, -4.8431, 15-16.v.2018, 1♀, white pan trap, leg. P. Lhomme; Casablanca-Settat, Oueled Sghir, 32.8230, -7.6421, 23.ii.2018, 1♂, 1♀, A. Sentil & I.E. Abdouni, all UMONS.

Distribution.

Andrena alchata is known from Morocco and Algeria and was only described from the male sex ( Warncke 1974); the subspecies A. doursana agadira was known only from south-western Morocco and was described only from the female sex ( Warncke 1980), though the presence of putative males was noted.

Remarks.

Sampling at both Laanoucer and Oueled Sghir in northern Morocco resulted in the capture of males of A. alchata and females corresponding to A. doursana agadira on the wing at the same time. Other Truncandrena species were present, with females of Andrena ferrugineicrus Dours, 1872 and A. schmiedekneckti Magretti, 1883 captured at Laanoucer and males and females of Andrena varia Pérez, 1895 at Oueled Sghir. However, no males or females of A. doursana citreola Warncke, 1975, the form occurring in this part of Morocco, were recorded. This situation raised the possibility that A. alchata and A. doursana agadira are actually synonymous.

Captured females are darker than A. d. citreola (compare Figs 117 , 118 ) and can be separated by the colouration of the hairs of T5-6 flanking the pygidial plate which are dark brown (Fig. 119 ) not light brown as in A. d. citreola (Fig. 120 ). The contrast of these hairs against the abdomen is greater in A. d. citreola as the underlying integument is lighter and weakly metallic green (see also Fig. 118 ) with overlying pale hair bands, whereas in captured females the integument is dark and the hair bands are darker (Fig. 119 ). The colouration of the hairs on the frons and along the inner margin of the compound eye are also important; these are a mixture of brown and black in captured females (Fig. 121 ), and white to light brown in A. d. citreola s.s. (Fig. 122 ). In these characters, captured females match A. d. agadira perfectly ( Warncke 1980).

Warncke did not describe male of A. d. agadira , commenting that they were indistinguishable from other A. doursana subspecies. In contrast, males of A. alchata are easy to distinguish as the white markings on the face of A. alchata are much more extensive, covering the clypeus and the lower paraocular areas (Fig. 123 ) whereas in A. d. citreola the single white marking is small and is restricted to the very tip of the clypeus which forms a clear raised protrusion (Fig. 124 ). There are also genitalia differences, in A. alchata the outer margin of the gonostyli is curved inwards (evenly rounded in A. d. citreola ), and the penis valve is comparatively wider.

A female corresponding to A. d. agadira and a male A. alchata were selected from the same site (Laanoucer, 2.v.2018) for molecular investigation. A cox1 fragment of 263 base pairs was obtained after sequencing. A complete homology between the sequences of the female (GENBANK SUB7440720) and the A. alchata male (SUB7440720) was found, confirming their conspecificity. However, this result raises a difficult issue, as Warncke believed the males of A. d. agadira to be identical to other A. doursana subspecies. This therefore means that either A. alchata and A. d. agadira are not synonymous, and simply very similar morphologically in the female sex, or the undescribed A. d. agadira males are incorrectly associated with the type series females. Given this uncertainty, it is not appropriate to propose synonymy between A. d. agadira and A. alchata until genetic sequences can be obtained from the locus typicus to clarify sex associations in this region. What is clear is that captured females represent A. alchata , but given the large degree of variation in the colour of Truncandrena pubescence, it is possible that they simply resemble females of A. d. agadira . As such, we do not describe females here until this situation can be clarified further.

Figures

Figures 117 - 124. Andrena (Truncandrena) alchata Warncke, 1974 117 female profile 119 female tergites 121 female face 123 male face. Andrena (Truncandrena) doursana citreola Warncke, 1975 118 female profile 120 female tergites 122 female face 124 male face.