Corresponding author: Simon van Noort (
Academic editor: Gavin Broad
The platygastrid subfamily
van Noort S, Lahey Z, Talamas EJ, Austin AD, Masner L, Polaszek A, Johnson NF (2021) Review of Afrotropical sceliotracheline parasitoid wasps (Hymenoptera, Platygastridae). In: Lahey Z, Talamas E (Eds) Advances in the Systematics of Platygastroidea III. Journal of Hymenoptera Research 87: 115–222.
The subfamily
The Afrotropical sceliotracheline fauna is currently represented by 35 described species (number listed in brackets following each genus) and numerous undescribed species contained in eight genera:
We review the Afrotropical
Images were acquired at
Morphological terminology follows
Delimitation of the Afrotropical biogeographical region is based on the concept of the old Ethiopian region of
Accession/catalogue numbers prefixed with
The subfamily is poorly defined with no confirmed synapomorphic characters uniting the currently included taxa. Many, but not all, sceliotracheline genera possess foamy structures, which, among platygastroids, are limited to
1 | Wings absent (A); T1 fused with T2 and S1 fused with S2, with no evident sulcus (A, B); frons with a transverse furrow above torulus |
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– | Wings fully developed (a) extending to at least T2 (b); T1 separated from T2 and S1 from S2 by a sulcus (b), sulcus sometimes partly obscured by dense pilosity (b); frons above torulus without transverse furrow |
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2 | Spur of fore tibia combed (pts) ( |
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– | Spur of fore tibia without comb |
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3 | Pronotum with medial longitudinal sulcus (pms) (A); sternite 2 with long setae (B) |
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– | Pronotum without medial sulcus (a); S2 glabrous (b) |
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4 | Fore wings and microtrichia distinctly bicolored, giving the appearance of patches or stripes |
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– | Fore wings and microtrichia not bicolored |
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5 | Fore wing with tubular submarginal vein (A); admedian depressions (adm) present, may be weak (A); transepisternal line present (tel) (B) |
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– | Fore wing without veins (a); admedian depressions absent (a); transepisternal line absent (b) |
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6 | Fore wing with rudimentary submarginal vein, only sclerotized for about half its length (A); |
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– | Fore wing with submarginal vein fully sclerotized, ending in knob (a, b); |
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7 | Propodeum medially with single keel (A); metasomal depression not visible; notauli absent (A); scutoscutellar sulcus foveolate (A); anterior T2 with a transverse line of foveae; in females, ventral A8–A9 projecting distally; male antenna with long setae; submarginal vein of fore wing distinctly surpassing basal 0.33 of wing (B) |
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– | Propodeum with H-shaped foamy structure (a); metasomal depression delimited by lateral propodeal carinae; notauli usually abbreviated, triangular (a), absent in a few species; scutoscutellar sulcus simple (a); anterior T2 with two pits, without a line of foveae; antennae variable, but not as above; submarginal vein of fore wing reaching at most to basal 0.33 of wing (b) |
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Afrotropical: South Africa (
Unknown.
The
1 | Gena distinctly concave in anterior view (A); pronotal shoulders well-developed, pronotum anteriorly with well-defined neck (B); notauli narrow, 7× longer than wide (B) |
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– | Gena straight or convex in anterior view (a); pronotal shoulders more evenly rounded, pronotum anteriorly with weakly defined neck (b); notauli broad, at most 5× longer than wide (b) |
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2 | Metasoma dark brown, not strongly contrasting with head and mesosomal coloration (A); notauli 5× longer than wide (B); |
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– | Metasoma yellow-orange or red-orange, contrasting with darker head and mesosoma (a); notauli at most 3× longer than wide (b); |
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3 | Notauli posteriorly widely spaced relative to scutellar width (red lines), meeting the mesoscutellar sulcus less than the posterior notaular width from the lateral margins of the scutellum (white lines) (A); mesoscutum polished between the notauli (A); |
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– | Notauli positioned closer together relative to scutellar width (red lines), meeting the mesoscutellar sulcus at least double the posterior notaular width from the lateral margins of the scutellum (white lines) (a); mesoscutum with alutaceous reticulation between the notauli (a); |
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Named after the type locality, Anyskop farm. Noun in apposition.
South Africa (Western Cape).
Overall a much lighter-coloured species as in
Unknown.
South Africa (Eastern Cape) (
A distinctly coloured species with an orange-yellow metasoma contrasting strongly with the red-brown mesosoma and dark brown head;
Named for the similar coloration and habitat affiliation to the Quagga, an extinct Plains Zebra subspecies that previously existed in the Cape region. These zebras had reduced stripes and a distinct orange hue on the flanks and hind quarters, which is also reflected in the coloration of the metasoma of this new
South Africa (Eastern Cape).
Named after Hamish Robertson, previous director and entomologist at the Iziko South African Museum, colleague and friend of Simon van Noort. Together they implemented the entomological sphere of the Conservation Farming Project through which the type specimen was procured. Noun in the genitive case.
South Africa (Eastern Cape).
Head in dorsal view wider than long, subellipsoidal to lens-like. Occipital pit not developed. Temples very short to almost absent. Posterior ocellus at most 1 diameter distant from inner orbit;
Afrotropical: Ivory Coast, Madagascar, South Africa, Tanzania. Cosmopolitan, excluding Antarctica and New Zealand (
Solitary and gregarious endoparasitoids of mealybugs and cochineals (
Unknown.
Tanzania (
Parasitoid of the mealybug
South Africa. Introduced into Spain as a biocontrol agent of
Unknown.
Tanzania (
Only a single male is present in the
Solitary endoparasitoid of the citrus mealybug
South Africa (
The
Parasitoid of
South Africa (
Parasitoid of
Ivory Coast (
Parasitoid of mealybugs on
Madagascar (
Short, stocky, dorsoventrally flattened species, with long wings without distinct veins; head in lateral view somewhat opisthognathous; antennal formula usually 10-10, rarely 8-8 (e.g.
Afrotropical: Kenya, Madagascar, South Africa (new records). Cosmopolitan, excluding Antarctica and New Zealand (
Solitary and occasionally gregarious endoparasitoids of whiteflies (
USA • 2♀♀, 1♂ card mounted; 13♀♀, 2♂♂ loose in gelatine capsule; Florida, Gainsville; xi. 1989; Ru Nguyen; ex
Parasitoid of the citrus blackfly,
China, but introduced to most tropical areas of the world as part of biocontrol programs (
No published evidence of introduction or establishment of
Minute species (0.6–1.3 mm) with body slightly to considerably depressed dorsoventrally; mostly melanic, with brightly coloured appendages; vertex rounded without hyperoccipital carina.
Afrotropical: Kenya, South Africa, Tanzania, Togo. Cosmopolitan, excluding Antarctica (
Solitary endoparasitoids of weevil (
There are numerous further undescribed species of
Egg parasitoid of
Kenya (
Named after the Latin word for speed with reference to the notauli and median sulcus configuration on the mesoscutum that is reminiscent of GT racing stripes. Noun in apposition.
Both sexes are immediately distinguishable by the presence of a median mesoscutal line, which is absent in the other species. The notauli extend far forward, almost meeting the admedian depressions. Males are unique amongst other members of the genus, and the subfamily
Unknown.
South Africa (Eastern Cape).
This species strongly resembles the genus
Unknown.
South Africa (Buhl 2001).
Unknown.
Togo (Buhl 2014).
Unknown.
Togo (Buhl 2014).
Unknown.
Tanzania (Buhl 2010).
Unknown.
Togo (Buhl 2014).
Unknown.
Tanzania (Buhl 2010).
Robust, usually dark-coloured species.
Unknown.
Afrotropical: Kenya, Madagascar. Palearctic: France, Greece, Iran, Israel, Italy, Mongolia, Montenegro, Spain, Thailand, Turkey. Indomalayan (Oriental): China, India, Philippines (
Unknown.
Kenya (new country record here). Also present in the Palearctic (Spain) (
Body shape variable, from stocky and highly convex to elongate, spindle-like. All Old World species are apterous, as are the described Neotropical species with some undescribed New World species being micropterous or full-winged. Mostly yellow or light brown. Posterior ocellus contiguous with inner orbit; ocellar triangle high. Cheek and postgena with deep longitudinal excavation for housing of scape. Antennal clava of both sexes ovoid, 4-merous. Mesosoma of flightless species subrectangular, with most sclerites fused. Fore wing (when present) with short rudiment of submarginal vein without apical knob. Metasoma highly convex both dorsally and ventrally. T1 fused with T2, and S1 with S2, into solid sclerite; felt fields absent from S2 (
Afrotropical: Kenya, Madagascar, Malawi, Seychelles, South Africa, Tanzania (
Unknown. Predicted to be living near the ground, possibly as leaf-litter inhabitants (
The Old World species are all apterous, as are the described Neotropical species:
Sexual dimorphism is slight in some species with morphological differences only apparent in the shape of the antennal club (
There are two apparent species-groups in the Afrotropical region defined by the presence or absence of a hyperoccipital carina. We predict that these two groups will be further supported by the presence or absence of a metasomal horn in females, once both sexes of the known species are discovered.
Hyperoccipital carina present.
Sexual dimorphism slight, females without metasomal horn on T1.
Absence of a sulcus between the lateral pronotum and mesopleuron.
Hyperoccipital carina absent.
Sexual dimorphism strong, females with metasomal horn on T1 that is developed to varying degrees in size.
Sulcus between the lateral pronotum and mesopleuron present.
The only other described Old World species, the Australian
The following key includes diagnostic characters enabling both sexes to be keyed out where known. Males of four species (
(modified after
1 | Hyperoccipital carina present between the lateral ocelli (distinct from occipital carina) (A, B) |
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– | Hyperoccipital carina absent, if carina present between ocelli then clearly part of occipital carina (a, b) |
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2 | Head and mesosoma covered with small compact plates (A, B, C) |
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– | Head and mesosoma covered with imbricate (squamate) sculpturing (a) |
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3 | Base of metasoma with obvious foveate pits (A); occipital carina strong and visible in dorsal view (A); mesoscutum and scutellum evenly convex (B) |
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– | Base of metasoma without obvious foveate pits, with bifurcate projecting medial plate (a); occipital carina not visible dorsally; posterior mesoscutum and scutellum raised into a medial plateau-like (a, b), transversely ellipsoidal projection (a); clypeus produced into nasute-like process (b) |
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4 | Anterolateral mesosoma with large pit (A); dorsal mesosoma longitudinally striate (B); metasoma normal, tergite 1 not developed into a horn (B) |
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– | Anterolateral mesosoma without large pit (a); dorsal mesosomal surface reticulate-coriaceous (may be entirely excavated) (b); tergite 1 in females developed into a horn |
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5 | Metasomal horn present (females) |
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– | Metasomal horn absent (males) |
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6 | Excavation encompasses entire dorsal length of mesoscutum (A); metasomal horn extending anteriorly over three-quarters of mesosoma (A) |
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– | Mesoscutum with dorsal surface present, excavation restricted to posterior half of mesoscutum (a, b); metasomal horn at most extending over posterior half of mesosoma (a, b) |
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7 | Metasomal horn longer than dorsal surface of mesosoma (A, B); occipital carina low on posterior head; vertex smoothly rounded (B) |
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– | Metasomal horn shorter than dorsal surface of mesosoma (a); occipital carina high on posterior head (a, b); vertex interrupted by occipital carina (a, b) |
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8 | Metasomal horn barely developed, represented by raised area with longitudinal carinae (A, B), shallow excavation restricted to posterior face of mesosoma (A, B) |
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– | Metasomal horn distinct, two-thirds of dorsal length of mesoscutum (a, b), excavation encompasses c. a quarter of mesoscutal length (a, b) |
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9 | Posterior margin of mesosoma broadly pointed in dorsal view, with short longitudinal carinae present along posterior border (A); in lateral view mesosoma gently humped one-third of distance from posterior margin (B) |
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– | Posterior margin of mesosoma rounded in dorsal view, with narrow smooth posterior border containing scattered short setae in pits (a); in lateral view mesosoma without dorsal hump (b) |
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Australia (
Malawi (
SOUTH AFRICA • 1♀, 1♂; Kwazulu-Natal, Umtamvuna Nature Reserve;
There is the possibility that the additional material cited above may include two similar looking species. There is some variation present within the available material with regard to colouration, dimensions of the mesosoma, and degree of striation on the metasoma. Whether this is intra-specific variation, or indicative of the presence of additional species, requires a focused morphologically assessment, ideally with the additional aid of barcoding tools.
South Africa (
Tanzania (
Tanzania (
South Africa • 1♀; Western Cape, Gamkaberg Nature Reserve;
Named for the exceptional clypeal modification into a nasute-like process. Latin adjective.
South Africa.
We suspect that the central fovea ringed by a carina that is terminally situated on the clypeal nasute-like process is olfactory in nature, potentially containing chemo-sensillae that may be involved in host location, although males also possess this adaptation, so possibly it is involved in mate recognition. It is likely that the species lives in the leaf-litter habitat and probably attacks insect or arachnid eggs.
The single female from Gamkaberg Nature Reserve is uniformly orange-yellow, has a smoother mesopleuron, and weaker clypeal and posterior mesosomal protrusions. Overall, the surface sculpturing is also weaker. The specimen is smaller than the type series specimens and these differences may simply be related to the reduced size. There is, however, the possibility that this specimen represents a second closely related, undescribed species, but until further specimens are acquired to assess the degree of intraspecific variation this specimen is considered to belong to
Tanzania (
South Africa (
Kenya (
Seychelles (
Fore wing with very short, tubular R vein terminating in a knob and at least some microtrichia of the fore and hind wings in the form of short, scale-like pegs; distinctive colour of the adult (most species are yellow, orange, red, or a combination thereof); frontal ledge present on the lower frons in all but one species; interantennal process present, bilobed in most species; and tract of dense setae on the metatibia.
Endemic to the Afrotropical region: Benin, Burkina Faso, Gambia, Ghana, Ivory Coast, Kenya, Madagascar, Mali, Mozambique, Nigeria, South Africa, Tanzania, Zambia (
Unknown.
Ghana, Ivory Coast (
South Africa (
South Africa (
Madagascar (
Kenya, Tanzania (
Benin, Burkina Faso, Gambia, Ivory Coast, Mali, Nigeria (
South Africa (
South Africa (
Madagascar (
Zambia (
The genus
Unknown, but likely to be parasitoids of arthropods living in the leaf litter habitat (see discussion).
1 | Pronotum and occiput glabrous (A); occipital pit present (A); acetabular carina (ac) and mesopleural epicoxal sulci (mes) not converging, fore and mesocoxae separated by more than one fore coxal width (B); fore wing of normal shape, twice as long as wide (C) |
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– | Pronotum and occiput setose (a); occipital pit absent (a); acetabular carina (ac) and mesopleural epicoxal sulci (mes) converging, fore and mesocoxae separated by less than one fore coxal width (b); fore wing narrow and elongate, at least 3× longer than wide, anterior and posterior margins subparallel (c) |
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2 | Genal and pronotal rugae present (A); mesoscutellum compressed, narrow, 2.5× wider than long (B); mesoscutellar disc medially with broad, shallow, longitudinal excavation, axillar carinae weakly raised (B); costal margin of hind wing with thick band of black sclerotization that runs nearly the entire length of the wing (B); fore wing extending beyond posterior margin of T2 |
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– | Genal and pronotal rugae absent (a); mesoscutellum broader, twice as wide as long (a); mesoscutellar disc square, medially and longitudinally evenly raised into a hump, laterally defined by strongly raised longitudinal axillar carinae (b); costal margin of hind wing not sclerotized; fore wing not reaching posterior margin of T2 (c) |
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South Africa • ♀; Eastern Cape: 1♀; 1♂ Schilpad Laagte Farm, (14.7 km 229°SW Kirkwood);
The shape and colour pattern of the fore wings immediately distinguish this species from the other two species, which either have a much more brachypterous or normal fore wing shape. The hind wing costal margin has a thick band of black sclerotization that runs nearly the entire length of the wing, which is absent in the other two species. Strong genal and pronotal rugae are present, absent in the other two species. The mesosoma is the most longitudinally compressed of the three species with the pronotum, mesoscutum and scutellum all extremely transverse and of equal length. Strong white setae are present on the occiput and pronotum. The mesoscutum is posteriorly strongly raised in lateral view; mesoscutum compressed, narrow 2.5× wider than long, without raised carinae; pronotal shoulders taper to point; wings slightly shortened, extending just beyond posterior margin of second tergite, 3× longer than wide.
Named by Brues after the collector of the two type specimens, Dr Hans Heinrich Justus Carl Ernst Brauns, a medical doctor who practiced in Willomore in the Eastern Cape. The Brauns collection of
Gamtoos Thicket (coastal basin of the Gamtoos River Valley, south of the Baviaanskloof Mountains and along some smaller river valleys such as that of the Kromme River; also found north of the Baviaanskloof Mountains in more xeric conditions on some low ridges south and southeast of Steytlerville; altitude 0–700 m).
Sundays Noorsveld (mostly north of the Klein Winterhoek Mountains, centred around Waterford and the Darlington Dam and a smaller area from Jansenville westwards; also some patches south of this mountain range west of Kirkwood in the Sundays River Valley; altitude 100–600 m).
Sundays Thicket (from the surrounds of Uitenhage and the northern edge of Port Elizabeth into the lower Sundays River Valley to east of Colchester and northwards to the base of the Zuurberg Mountains and stretching westwards north of the Groot Winterhoek Mountains to roughly the Kleinpoort longitude; also an extensive area north of the Klein Winterhoek Mountains including much of the Jansenville District and parts of the far-southern Pearston District and far-western Somerset East District; altitude 0–800 m).
Distribution of
The current distribution is likely to be an artefact of under-sampling and the species is expected to be more widespread in the Eastern Cape (Fig.
The female specimen (Fig.
This species is immediately identifiable by the appearance of the fore wings which are of normal shape, and uniformly fuscous, without dark patches or strong microtrichiae, in contrast to the elongate and chromatically modified fore wings in the other two species. An additional diagnostic character is the presence of an occipital pit, which is absent in the other two species. The mesosoma is correspondingly less longitudinally compressed, with the mesocutum and mesopleuron being more normal in proportions. The pronotum and occiput are glabrous without the long setae present in the other two species. The acetabular and mesopleural epicoxal sulci do not converge as in the other two species, and, correspondingly, the fore and mesocoxae are separated by more than one fore coxal width (separated by less than the fore coxal width in other two species).
Named after the Karoo area wherein both main collection localities fall. Noun in apposition.
Western Little Karoo (the unit covers most of the western basin of the Little Karoo from the confluence of the Groot and Gouritz Rivers in the west as far as Anysberg by surrounding this mountain range and also extending along the northern flanks of the Klein Swartberg; two larger patches of the Western Little Karoo are found immediately to the east and south of Touws River, and one small isolated patch fringes the Langeberg Mountains in the Montagu area; altitude 160–1060 m (most of the area at 300–860 m).
South Rooiberg Sandstone Fynbos (southern slopes of the mountains of Rooiberg, Gamka and the Amalienstein Ridge-Sandberg-Bakenskop range; altitude 350–1490 m on the summit of Rooiberg).
The current distribution is likely to be an artefact of under-sampling and the species is expected to be more widespread in the Western Cape.
This species is immediately distinguishable by the brachypterous wings, which have a unique colour pattern, are extremely narrow, 4× longer than wide, and do not extend beyond the posterior margin of tergite 2. It shares the lack of the occipital pit, presence of long setae on the pronotum, and presence of strong microtrichiae with
Comparison of selected characters for the three
Named in honour of John Midgley, who first collected specimens of the new species as part of his PhD project. Noun in the genitive case.
Camdebo Escarpment Thicket (south-sloping face of the Great Escarpment, forming an arc from Bruintjieshoogte in the east via the Coetzeeberg Mountains and Graaff-Reinet (including Spandaukop and the isolated Rooiberg) to Kamdebooberg and Aberdeen in the west; altitude varies from 570–1600 m, with most of the area between 700–1200 m).
The current distribution is likely to be an artefact of under-sampling and the species is expected to be more widespread in the Eastern Cape, but possibly restricted to higher altitudes in Camdebo Escarpment Thicket.
The circumscription and phylogenetic affinities of the subfamily
Based on current specimen records there appears to be a degree of habitat fidelity within the populations of all three
Based on the sampling techniques (mostly leaf litter extraction, pitfall traps, and yellow pan traps, with only two records from Malaise traps) that were successful in collecting specimens of
With further intense sampling, using continuous inventory surveys comprising a variety of collecting methods, we expect that more
Thanks to Marlene McKay, Richard and Kitty Viljoen (Asante Sana Game Reserve); and Cape Nature reserve managers, Tom Barry (Gamkaberg Nature Reserve), and Marius Brand (Anysberg Nature Reserve) for providing permission to run long-term inventory surveys on their reserves and for logistical support in the field. Aisha Mayekiso, the late Nosiphiwo Goci, Mmamotswa Mosweu, Yvonne Samuels, the late Nkosinathi Babu, Victor Mutavhatsindi, Tiyisani Chavala, Susanna das Neves, Tiffany Wynford, and Aabid Abrahams are thanked for their dedication to processing samples at Iziko South African Museum. Dawn Larsen and Robyn Tourle are thanked for their assistance in the field during the Conservation Farming Project co-ordinated by the National Botanical Institute (now SANBI). Thanks to John Donaldson and Ingrid Nanni from SANBI for making this project a reality. Eastern Cape Nature Conservation and Cape Nature (Western Cape Province) granted collecting permits. CSIRO Publishing granted permission to reuse the