Ischnostomiella denticeps Krikken, 1978

Irish, Renzo Perissinotto John, 2024, A new species of Ischnostomiella Krikken, 1978 from the Limpopo Province of South Africa (Scarabaeidae: Cetoniinae, Xiphoscelidini), Fragmenta entomologica 56 (1), pp. 13-20 : 17-18

Ischnostomiella denticeps Krikken, 1978

( Figs 2 , 3 )

Ischnostomiella denticeps Krikken, 1978: 269 ; Holm & Marais 1992: 17; Sakai & Nagai 1998: 1666; Krajcik 1999: 1; Beinhundner 2005: 79; 2017: 366.

Remarks. The total length of this species ranges from 8 to 12 mm, while its maximum width is 4.5-5.0 mm ( Krikken 1978, Beinhundner 2017). The species exhibits a substantial degree of dorsal polychromatism, with most specimens being completely black to dark brown ( Fig. 2 A, C ), but a minority actually possessing brown-orange elytra along with a dark pronotum, scutellum and head ( Fig. 2 B ). One male specimen housed in the SMWN actually resembles closely the dorsal chromatic pattern of I. rudebecki , in that it exhibits predominantly testaceous-orange pronotum, elytra, tarsi and tibiae. It differs, however, from the new species in all the other diagnostic characters highlighted above.

The period of adult activity seems centred around late spring to early summer (Nov-Jan), most likely coinciding with the peak period of rainfall in the region. Holm and Marais (1992) reported that females were caught in flight, while Thierry Garnier found his series near Omaruru dead on top of a building roof (pers. comm.). One specimen from Windhoek has actually been found on Acacia sp. (= Vachellia ) flowers, thus suggesting a potential feeding ability. All pre-adult stages of the species remain unknown.

Distribution. The species appears to be restricted to the central mountainous region of western Namibia, from the Khomas Hochland to the Erongoberge ( Fig. 3 ).

Data records. Type series: Holotype ♂, Namibia (Sudwestafrika), Windhoek, SE 22 17 Ca , 18-23.XII.1973, no H15555 ( SMWN) ; Paratype ♂, Namibia (S.W Africa), Okanjande , Burgeon ( Sakai & Nagai 1998: Pl. 142, fig. 130; MRAC) . Other records : 2 ♂ + 1♀, Central Namibia, Reg. Omaruru, Epako Lodge, 01.1996, found dead on a roof, T. Garnier leg. ( TGMF) ; 1 ♂, ibidem ( RPGS) ; 2 ♀, ibidem ( GBEG) ; 1 ♂ + 1 ♀, ibidem, 01.1997, T. Garnier leg. ( TGMF) ; 2 ♀, ibidem ( GBEG) ; 1 ♂, Namibia Central , 28 Km South Karibib, 7.III.2018, S Prepsl leg. ( PMBC) ; 1 ♂, Südwestafrika, Windhoek, S.O. 2217 Ca , 6.XII.1970, Akazienblüte, R. Oberprieler, Ischostomiella denticeps m., det. J. Krikken 1981 ( SMWN) ; 1 ♀, ibidem, 3.I.1971, im Flug, R. Oberprieler, Ischnostomiella denticeps m., det. J. Krikken 1981 ( SMWN) .

Figures

Fig. 2 – A, dark ♂, Namibia, Karibib; B, brown-orange ♂, ibidem; C, dark ♀, Namibia, Omaruru. I. werneri Beinhundner, 2005: D, Holotype ♂, Botswana, Gweta; E, Paratype ♂, ibidem; F, “allotype” ♀, ibidem.

Fig. 3 – Distribution range of the three species of Ischnostomiella Krikken, 1978 within the southern African region. (Map: Google Earth Pro with image from Landsat/Copernicus 12/14/2015).