Nomada whiteheadi EARDLEY & SCHWARZ, 1991

Kuhlmann, Michael, 2023, The South African species of the bee genus Nomada SCOPOLI, 1770 (Hymenoptera, Apidae), Linzer biologische Beiträge 55 (1), pp. 155-186 : 175-181

Nomada whiteheadi EARDLEY & SCHWARZ, 1991 (Figs 89-110)

Nomada whiteheadi EARDLEY & SCHWARZ, 1991: 18-19 . Holotype ♀ ( Graafwater , South Africa) (SAMC), examined.

A d d i t i o n a l m a t e r i a l e x a m i n e d:(12specimens). SouthAfrica : 3♀♀, 8 km WNW Leliefontein, Fynbos, road side, 30°15´58´´S 18°03´17´´E, 1190 m, 14.ix.2017, leg. M. Kuhlmann ( RCMK) ; 2♀♀, Garies , Diknek, 3017AD [30°19´S 17°16´E], 18.viii.1995, leg. V.B. Whitehead ( SAMC) ; 1♀, Nieuwoudtville , Wild Flower Reserve, Car Park East, 31°22´18´´S 19°08´58´´E, 730 m, 14.viii.2010, leg. M. Kuhlmann ( RCMK) ; 1♀, Graafwater [32°09´S 18°33´E], x.1947, leg. Mus. Exp. ( SAMC) ; 1♀, Cl. William [Clanwilliam], Capland [32°11´S 18°53´E], 20.viii.1927, leg. Dr. Brauns ( SAMC) ; 2♀♀, Paleisheuwel , Alexandershoek, 3218BC [32°18´S 18°43´E], 12.ix.1991, leg. V.B. Whitehead ( SAMC) ; 1♀, Sauer , Suurfontein, 3120CC [32°50´S 18°40´E], 1.ix.1994, leg. V.B. Whitehead ( SAMC) ; 1♀, idem., Sauer , Suurfontein, 3218DC, 25.viii.1994 ( SAMC) .

Although the female of N. whiteheadi was described by EARDLEY & SCHWARZ (1991) it is here redescribed to highlight the differences to its previously unknown close relatives.

Figs 89-94: Nomada whiteheadi EARDLEY & SCHWARZ, 1991 , ♀ (89) dorsal view; (90) lateral view; (91) head; (92) scutum; (93) propodeum; (94) metasoma.

The male of N. whiteheadi was described by EARDLEY (1993) based on three specimens, one of them collected in Vanrhynsdorp was examined and perfectly matches the description (located in SAMC, not in DNMNH (former TMSA) as indicated in the publication). The two other males mentioned by EARDLEY (1993) were not available for study. Thus, redescription and images are solely based on this individual. However, there are indications that females and males might be incorrectly associated (see "Remarks" below).

D i a g n o s i s: The female of N. whiteheadi is unique by the conspicuous apical, broad comb of strong flat and black, slightly upwards bent setae of the pseudopygidial area on T5 ( Fig. 98 ). The male is characterised by the comparatively dense and long greyish-white pubescence of head and mesosoma ( Figs 99-102 ). Pygidial plate finely punctate, narrow and flat triangular with rounded tip ( Fig. 104 ). Genitalia and S7 as illustrated ( Figs 108-110 ).

D e s c r i p t i o n

F e m a l e: Body-length: 9.6-13.2 mm (Habitus: Figs 89-90). Head: Head black, reddish-brown are: antennal scape except tip, ventral side of antennal flagellum (except first flagellar segment orange), lower margin of the clypeus (to a variable extent), malar area, base and tip of mandible (Fig. 91). Coloration of labrum variable, from completely black to yellowish-orange, intermediate forms sometimes with small apical brown spot(s) and yellowish-orange margin(s) ( Fig. 97 ). Specimens from higher altitude generally more blackish. Head slightly broader than long. First flagellar segment longer than second (ratio 1: 0.76) ( Fig. 95 ), all flagellar segments longer than wide. Supraclypleal area broadly adjoining the clypeus, longitudinal keel raised with highest point between the base of the antenna. Clypeus in lateral view slightly asymmetrically convex, with the highest part in the upper half and flattened in the lower half, punctation fine and dense, between punctures smooth and shiny ( Fig. 96 ). Labrum transversely oval in shape, arcuate apical transverse ridge with medially three or four asymmetrically arranged small, yellowish translucent teeth on its upper margin, surface finely punctate, smooth and shiny between punctation ( Fig. 97 ). Mesosoma: Integument black, reddish-brown are: pronotal lobe, pair of longitudinal stripes on the scutum (variable in extent), tegula, axilla (Fig. 92), scutellum with pair of lateral spots on anterior swelling and lower posterior edge, metanotum except lateral margin and horseshoe-shaped maculation (variable in extent) on the mesepisternum (Fig. 93). Scutum and propodeum finely punctate, shiny and smooth between punctures; scutellum and metanotum with slightly finer punctation, matt; scutellum medially depressed and laterally with distinct swelling. Wings: Wing venation reddish-brown at the base, apically brownish to black, membrane hyaline brown (Fig. 90). Legs: Front leg predominantly reddish-brown with black and brown maculation, tibia brownish-black with transversal reddish-brown spot, mid and hind legs predominantly black with reddish-brown maculation (Fig. 90). Hind tibia apically with three to four straight black spines, outer spine sometimes slightly paler and thinner. Metasoma: Metasoma mostly black; reddish-brown are posterior half of T1, all of T2, T3-4 with a narrow transverse stripe anterior of the marginal zone, T5-6 posteriorly lighter dark brown (Fig. 94), S1-3 mostly reddish-brown with black maculation, S5-6 black with small reddish-brown stripe posteriorly. Punctation of T1 more scattered than on following terga, punctures are about as far apart as their diameter, following terga densely punctate and matt, punctation of T2-6 successively coarser, marginal zones of T1-4 smooth and impunctate. Posterior margin of T5 medially emarginate and slightly raised, pseudopygidial area on T5 posteriorly with a crest of strong blunt black, slightly upwards bent setae that are directed backwards, this crest partly covered by a sparse transverse patch of thinner long yellowish to silverish hairs ( Fig. 98 ). Pygidial plate broad and flat triangular with rounded tip, finely punctate ( Fig. 98 ).

M a l e: Body-length: 11.3 mm (Habitus: Fig. 99 ). Head: Head black, reddish-brown are: lower 2/3 of antennal scape, ventral side of antennal flagellum (except first flagellar segment orange), lower margin of the clypeus, malar area, mandible except tip and lateral maculation ( Fig. 100 ), medioapical margin of labrum ( Fig. 106 ). Head broader than long and covered with dense silverfish hair. First flagellar segment longer than second (ratio 1: 0.77) ( Fig. 105 ), all flagellar segments longer than wide. Supraclypleal area with longitudinal keel raised with highest point below the base of the antenna. Clypeus in lateral view slightly asymmetrically convex, with the highest part in the upper half and flattened in the lower part, punctation fine and dense, between punctures smooth and shiny. Labrum transversely oval in shape, no visible teeth, surface irregularly finely punctate, smooth and shiny between punctation ( Fig. 106 ). Mesosoma: Integument black, reddish-brown are: pronotal lobe, pair of longitudinal stripes on the scutum, tegula, axilla ( Fig. 101 ), scutellum with pair of lateral spots on anterior swelling and lower posterior margin, metanotum and horseshoe-shaped maculation on the mesepisternum ( Fig. 102 ). Scutum and propodeum finely punctate, shiny and smooth between punctures; scutellum and metanotum with slightly finer punctation; scutellum medially depressed and laterally with distinct swelling. Entire mesosoma except propodeum with long silverish hairs. Wings: Wing venation reddish-brown at the base, apically brownish to black, membrane hyaline brown. Legs: Front leg predominantly reddish-brown with black and brown maculation, mid and hind legs predominantly brown with reddish brown maculation. Hair fringes on the front tarsi ( Fig. 107 ). Metasoma: Metasoma black; reddish-brown are: posterior half of T1 except marginal zone and black transvers stripe anteriorly of the marginal zone, anterior half of T2, posterior margin of T6 ( Fig. 103 ), stripe in the middle of S1, anterior margin of S2 with narrow stripe, reddish-brown maculation on the anterior margin of S3. Punctation of T1 more scattered than on following terga, punctures are about as far apart as their diameter, following terga densely punctate and matt, punctation of T2-6 successively coarser, marginal zones of T1-6 smooth and impunctate. Pygidial plate narrow and flat triangular with rounded tip, finely punctate ( Fig. 104 ). Terminalia: Genitalia ( Figs 109-110 ) and S7 ( Fig. 108 ) as illustrated.

G e n e r a l d i s t r i b u t i o n: Thespeciesisendemictothewinterrainfall region in the west of South Africa.

H o s t: Females were observed to inspect and enter nests of Rediviva (Redivivoides) variabilis ( KUHLMANN, 2012) .

R e m a r k s: None of the three males, that were assigned to N. whiteheadi by EARDLEY (1993), was collected together with females. Thus, without additional information (e.g. DNA barcoding) they cannot be assigned with certainty to N. whiteheadi or one of the other very similar four or even five (including the more distantly related N. roggeveldi nov.sp.) species. However, until new evidence becomes available and for taxonomic stability this male is provisionally further treated as N. whiteheadi , although there are some doubts about its identity.

For sex association in Nomada general colour pattern and morphology of the labrum turned out to be useful characters (J. Smit, pers. comm.). While colour patterns are very similar in the five species of this complex, the male misses the arcuate apical transverse ridge with medially three or four asymmetrically arranged small teeth on its upper margin. They are typical for the females of N. erhardti nov.sp., N. maximiliani nov.sp., N. redivivoides nov.sp. and N. whiteheadi ( Figs 65 , 75 , 85 , 97 ). In addition, the male is unusually hairy ( Figs 99-102 ). Hence, it seems unlikely that this male belongs to N. whiteheadi and it might even represent a hitherto unknown new species.

Figures

Figs 95-98: Nomada whiteheadi EARDLEY & SCHWARZ, 1991, ♀ (95) first and second flagellar segments; (96) clypeus; (97) labrum; (98) pseudopygidial area and pygidial plate.

Figs 99-104: Nomada whiteheadi EARDLEY & SCHWARZ, 1991, ♁ (99) dorsal view; (100) head; (101) scutum; (102) propodeum; (103) metasoma; (104) pygidial plate.

Figs 105-110: Nomada whiteheadi EARDLEY & SCHWARZ, 1991, ♁ (105) first and second flagellar segments; (106) labrum; (107) front tarsus; (108) metasomal sternum S7; (109) genitalia dorsal; (110) gonostylus lateral.

Figs 63-66: Nomada erhardti KUHLMANN nov.sp., ♀ (63) first and second flagellar segments; (64) clypeus; (65) labrum; (66) pseudopygidial area and pygidial plate.

Figs 73-76: Nomada maximiliani KUHLMANN nov.sp., ♀ (73) first and second flagellar segments; (74) clypeus; (75) labrum; (76) pseudopygidial area and pygidial plate.

Figs 83-88: Nomada redivivoides KUHLMANN nov.sp., ♀ (83) first and second flagellar segments; (84) clypeus; (85) labrum; (86) pseudopygidial area and pygidial plate; (87) clypeus lateral; (88) teeth on labrum (dorsal view).