Durbadnus chubbi ( Forsius, 1930 )

Koch, Frank & Liston, Andrew D., 2012, Revision of Durbadnus Pasteels, 1954, with notes on other Afrotropical Blennocampinae and Allantinae (Hymenoptera: Symphyta: Tenthredinidae), African Invertebrates 53 (2), pp. 645-645 : 652-654

publication ID	https://doi.org/ 10.5733/afin.053.0204
persistent identifier	https://treatment.plazi.org/id/836E1D24-BB3B-FF87-FE5E-047BBFF3FD02
treatment provided by	Felipe
scientific name	Durbadnus chubbi ( Forsius, 1930 )
status

Treatment

Durbadnus chubbi ( Forsius, 1930)

Figs 10–15 View Figs 10–15 , 28, 29 View Figs 28–33

Monophadnus chubbi: Forsius 1930: 73–75 , ♀ ♂. Type locality: South Africa, KwaZulu-Natal, Durban .

Durbadnus chubbi: Pasteels 1954: 503 .

Blennocampa bensoni Forsius, 1931: 27–28 , ♀ ♂. Type locality: South Africa, Eastern Cape, Port St Johns .

Syn. n.

Kivua bensoni: Pasteels 1949 a: 60 .

Redescription:

Female.

Head black; labrum light brown, apical half of mandible reddish brown. Thorax black; pronotum, tegula, lateral lobes of mesoscutum except for a large black medial spot, lateral margin of medial lobe of mesoscutum, postspiracular sclerite, dorsal half of mesopleuron, and anepimeron orange. Legs blackish; tibiae and tarsi whitish, only at extreme apices of tibiae and tarsomeres 5 somewhat darker.Wings subhyaline; costa, subcosta and base of venation blackish, stigma and rest of venation light brown. Abdomen black.

Head narrowed behind eyes. (Antenna as long as head and thorax together; vide Forsius 1931 for Blennocampa bensoni . Flagella of Monophadnus chubbi holotype missing; vide Forsius 1930.) POL:OOL = 1.0:0.8. Postocellar area: width:length = 1.0:0.7, lateral furrows slightly divergent posteriorly and convex; a longitudinal medial furrow shallowly developed, especially at the anterior margin. Supra-antennal grooves large and deep, no furrow developed towards torulus. Interantennal area with very small medial groove. Eyes converge downwards, lower interocular distance as long as eye length. Supraclypeal furrow deep.

Head more or less micropunctate, shiny; pubescence on head pale, somewhat shorter than the diameter of lateral ocellus. Thorax sparsely micropunctate, shiny; pubescence pale, shorter than that on head. In fore wing, cell 2Rs as long as 1R1 and 1Rs united; stub of 2A+3A more or less straight at apex ( Fig. 10 View Figs 10–15 ).

Tergum 1 with moderately wide but deep medial excision.Terga transversally microridged, dull. Sawsheath in lateral view pointed at apex ( Fig. 11 View Figs 10–15 ), in dorsal view very narrow towards apex.

Lancet as in Fig. 12 View Figs 10–15 , with scattered, conspicuous longer setae at centre towards base; with approx. 27 serrulae; serrulae at centre very flat, truncate apically, with about 8–11 very small posterior denticles and 3 anterior denticles ( Fig. 13 View Figs 10–15 ).

Length 6.7–7.3 mm.

Male.

Colouration similar to that of female. Mesoscutum completely black, only lateral margin of lateral lobe orange. Fore femur dirty white, mid and hind femora dirty white at apices.

Head conspicuously narrowed behind eyes. Antenna 1.3 times as long as maximum width of head; flagellomere 1 0.9 times as long as flagellomeres 2/3 combined. POL:OOL= 1.0:0.6–0.8. Other features as for female. Penis valve as in Fig. 14 View Figs 10–15 ; parapenis and harpe as in Fig. 15 View Figs 10–15 .

Length 5.3–6.0 mm.

Type material examined:

Monophadnus chubbi . Holotype ( Figs 28, 29 View Figs 28–33 ): ♀: “ Holotype ” [red]; “Durban [29°51'S 31°01'E], Natal, 18.X.1920, C. N. Barker, 2578”; “ Monophadnus chubbi n. sp. ♀, Holotype, R. Forsius det.”; “ Holotype, Monophadnus chubbi Forsius ♀, teste: F. Koch, 2011” [red]; “ Durbadnus chubbi (Forsius) ♀, det.: F. Koch, 2011” ( DMSA). Condition:Antennae missing except for left antennomeres 1+2; legs and wings partly damaged. Paratype: 1♂ same data as holotype ( DMSA) GoogleMaps .

Blennocampa bensoni . Holotype: ♀ “Type, H. T.” [red circle]; “ S. Africa, R. E. Turner, Brit. Mus., 1923- 510”; “ Port St. Johns [31°38'S 29°32'E], Pondoland [= Eastern Cape], IX.1923 ”; “ B. M. Type, Hym., 1.379”; “ Blennocampa bensoni n. sp. ♀, holotypus, R. Forsius”; “ Holotypus, Blennocampa bensoni Forsius ♀, teste: F. Koch, 2011” [red]; “ Durbadnus bensoni (Forsius) ♀, det.: F. Koch, 2011” ( BMNH).Condition: Flagella and left rear tarsus missing GoogleMaps . Paratype: SOUTH AFRICA: KwaZuluNatal: 1♂ Eshowe [28°53'S 31°28'E], 1–22. iv.1926 ( UZMT). Condition: Thorax ventrally damaged by pin; two left apical flagellomeres missing GoogleMaps .

Other material examined: SOUTH AFRICA: KwaZuluNatal: 1♂ Umbilo [29°52'00"S 30°58'42"E], 14.x.1945, Marley ( DMSA) GoogleMaps .

Distribution: South Africa ( Fig. 34 View Fig ).

Remarks: The type material of M. chubbi was examined and compared with that of B. bensoni . It was not possible to find any significant differences between these specimens, and therefore they are considered to be conspecific.

Variability in D. chubbi occurs in the shape of the medial furrow of the postocellar area. This is distinctly developed in the female holotype of M. chubbi , weaker in the female holotype of B. bensoni , and absent in all males examined.

Durbadnus chubbi differs from other Durbadnus species in the large cell 2Rs of the fore wing, which is as long as cells 1R1 and 1Rs united ( Fig. 10 View Figs 10–15 ). In D. taegeri ( Fig. 20 View Figs 20–23 ) and D. obscuripes , 1Rs and 2Rs are about equal in their lower length; in D. chubbi , 1R1 is conspicuously shorter. Additionally, in the fore wing, the stub of 2A+3A of D. chubbi is more or less straight at the apex, whereas in D. taegeri and D. obscuripes it is apically furcate ( Fig. 20 View Figs 20–23 ).