Anthrenus (Anthrenodes) minor Wollaston, 1865

Holloway, Graham J. & Herrmann, Andreas, 2024, Redescription of Anthrenus (Anthrenodes) minor Wollaston, 1865 (Coleoptera, Dermestidae, Megatominae), Arquivos Entomolóxicos 30, pp. 269-276 : 271-272

Anthrenus (Anthrenodes) minor Wollaston, 1865 (BNHM)

Anthrenus claviger Wollaston, 1861 [BNHM]

Anthrenus albidoflavus Reitter, 1881 [HNHM]

Anthrenops minutus J. Sahlberg, 1903

Anthrenus (Nathrenus) canariensis Háva, 2022 (JHAC, Háva & Herrmann, 2022)

External features

BNHM: 1 male, 8 females ; AHEC: 2 males, 7 females . No difference in BL between BNHM and AHEC specimens (H=38.5, df=16, p=ns [not significant]). Mean male BL = 1.89 mm, mean female BL = 2.12 mm (H=7.5, df=16, p=ns), sample range 1.7 mm – 2.7 mm.

Habitus (showing variation), Fig. 1 . Integument dark brown (appearing chestnut brown in dissected individuals). Single brown ocellus in centre of head just below level of top of eyes. Vertex and face covered in dark brown scales admixed with yellow and white scales. Eyes not emarginated along inner margin. Deep excavations (fossae) along anterior part of pronotal lateral margins to accommodate antennae reaching at least halfway along pronotum in females, much further in males. From above, lateral margins of pronotum with projecting flanges reflecting the presence of the deep antennal fossae. Pronotum covered in dark brown scales admixed with varying amounts of white and yellow scales. Elytral coloration varies, although a consistent feature is the presence of three bands of white scales: sub-basal, sub-medial, and sub-apical. Most examples also show white scales along the basal margin, along the elytral suture, and apically. Mixed in with the white scales of the bands are varying amounts of pale brown to orange scales ( Fig. 1a ). One specimen studied sported many large, rounded pale cream scales ( Fig. 1b ), again with some admixed pale brown scales, but the overall effect was to produce a pale looking individual. Between the white bands, scales are either dark brown or orange ( Fig. 1c ). Ventrites ( Fig. 2a ) brown loosely covered in white scales that become slightly yellowy towards the lateral margins and especially towards the tip of ventrite 5.

Antenna ( Figs. 2b–2d ) 10-segmented, segments 1–8 honey-coloured to brown. Two segmented club densely hirsute and darker, dark brown in males ( Figs. 2b, 2c ), brown in females ( Fig. 2d ). Male antennal club longer than female and terminal segment longer than penultimate segment, but the ratio of lengths of segments 9 and 10 the same (1:1.7) in both sexes. One specimen (a male, Figs. 1b , 2c ) found with curved antennal club) but there was no evidence to suggest that this was anything other than A. minor . All legs components pale brown to honey-coloured.

Internal features (male)

Aedeagus ( Fig. 3a ) and sternite IX ( Fig. 3b ) of male shown in Fig. 1a , and the same in Figs. 3c and 3d for male shown in Fig. 1b . Average PL = 268 µm (PL/BL = 0.14). Parameres pale brown, slightly paler at posterior tips. From base parameres bow out and round before continuing to posterior tips as straight, parallel rods with barely any expansion at tips. There is no suggestion that Figs. 3a and 3c are different, rather the apparent differences are most likely caused by slight twisting of the parameres. Sternite IX ( Figs. 3b, 3d , SL = 298 µm) has a broad, short posterior lobe, heavily hirsute along lateral margins for posterior half of lobe and around the posterior margin with a few setae on the lobe disc. Below the posterior lobe, the margins sweep evenly out and back inwards to form two long, thin, curved anterior horns.

Internal features (female)

Sternite VIII ( Fig. 4a , SL8 = 420 µm) is a parasol shaped structure with a long, slender anterior stem and a broad posterior lobe (SW8/SL8 = 0.76). The anterior stem is sclerotinized (brown) but the sclerotinization does not extend into the posterior lobe. The anterior margins and outer corners of the posterior lobe are sclerotinized and the rest of the lobe is white. Long, stiff setae line the white posterior margin of the lobe. Tergite VIII ( Fig. 4b , TW = 340 µm [approx., TL/TW = 0.46) has a flat posterior margin lined with stiff, inward pointing setae. The setal distribution on the two halves of the tergite mirror each other closely. In addition to the marginal setae, there is one submarginal seta on each side below the angle of the posterior margin, and another, longer seta on each lateral margin. The lateral margins are straight before rounded hind angles. The anterior margin is strongly bilobed. There are no setae on the reticulated tergite disc.

Distribution

Anthrenus minor appears to be distributed in countries along a tight band between about 25º and 35ºN running across north Africa and into Asia ( Fig. 5 ), although it is not clear where the records beyond the Canary Islands come from. Mroczkowski (1968) states that A. minor can be found in several north African Countries and Greece, but identification of A. minor appears to be quite muddled. The north African records could well be correct, but the authors have not seen any specimens from this region and are unaware of anybody else who has.

Figures

Fig. 1.– Anthrenus minor, habiti, dorsal aspect. 1a.- Male, La Palma. 1b.- Male, Tenerife. 1c.- Female, La Gomera. Scale bars = 0.5 mm.

Fig. 2.– Anthrenus minor. 2a.- Ventrites, female, La Gomera (scale bar = 0.5 mm). 2b.– Antenna, male, La Palma (scale bar = 100 µm). 2c.– Antenna, male, Tenerife (scale bar = 100 µm). 2d.– Antenna, female, La Gomera (scale bar = 100 µm).

Fig. 3.– Anthrenus minor. 3a-b.– Male, La Palma, aedeagus and sternite IX, respectively. 3c-d.– Male, Tenerife, aedeagus and sternite IX, respectively. All scale bars = 100 µm.

Fig. 4.– Anthrenus minor, female, La Palma. 4a.– Sternite VIII. 4b.– Tergite VIII. All scale bars = 100 µm.

Fig. 5.- Distribution of Anthrenus minor according to Háva (2024).