Thesis (( M.Sc. (Molecular and Life Sciences)) -- University of Limpopo, 2007 / This dissertation reports on the results of field (Letsitele area) and laboratory investigations on the biology of Arytaina mopane, its ecological role as well as its physiological influences on the host plant Colophospermum mopane. The work is divided into three sections. Section one describes the various aspects of the biology of A. mopane, which includes the morphology of the eggs, nymphs and adults including the behaviour of nymphs and adults. Damage caused to the host plant by infestation as well as predation of A. mopane is discussed. Eggs are randomly laid on green and senescent C. mopane leaves, very often in clusters and along the veins. The eggs are black and conical in shape with a reticulatesculptured membrane surrounding each. Each egg has a pedicel at the apical end and a filament at the basal end. An egg is not attached by a pedicel (contrary to the literature) but glued to the leaflet surface. Arytaina mopane exhibits an incomplete metamorphosis with the life cycle consisting of an egg, 5 nymphal instar and an adult. The five nymphal stages differed only in size and minor morphological features except for development of wings. Wingpad development is prominent from the third instars onwards. Nymphs construct scutcheonlike encrustations, commonly known as lerps over their bodies, which partly protect them from enemies and desiccation. Lerps covered only about 0.2% of the adaxial leaflet surface, where they were more common. Nymphs feed by piercing through the epidermal cells into the vascular bundle tissue of the leaflet with their stylet to reach the phloem sap. Feeding damage by nymphs results in black and reddish-brown spots on the leaflet surface. Two forms of nymphs that varied in colour and abdominal markings were identified, that could either be two different female morphotypes of the species, gender variation or natural variation. When not feeding, adults rest almost motionless on the leaflet or petiole with their stylet withdrawn and wings folded. Adults prefer walking or crawling to flying between v leaflets but sometimes jump when disturbed. When violently disturbed adults did fly short distances and returned to settle on a leaf of the same tree. The mean adult body length is 3.5 mm. In the laboratory, the life span of adults ranged between 5 and 8 days. Predators include birds such as the Red winged starling (Onychognathus morio) and Tawnyflanked prinia (Prinia subflava), the Painted reed frog (Hyperolius marmoratus taeniatus), the larvae of the Brown lacewing (Neuroptera: Hemerobiidae), a suspected Coccinellid beetle, and ants belonging to the genus Crematogaster. The second section reports on the physiological influences in terms of the chemical composition of lerps and the mineral content of both infested and uninfested C. mopane leaves. Lerps, infested and uninfested C. mopane leaves were tested for carbohydrate and mineral contents. The carbohydrate constituent of lerps and leaves (infested and uninfested) was sugar in the form of glucose, fructose and raffinose. Infested leaves contained significantly higher amounts of the macro elements calcium and magnesium than uninfested leaves. The uninfested leaves in contrast had significantly higher amounts of nitrogen, potassium, iron and copper. The ecological role of the infestation on C. mopane is reported in section three. Colophospermum mopane leaves at certain times of the year are known to have high tannin levels, which presumably results in bitter tasting leaves. The sweet encrustation (lerp) of A. mopane, apart from possibly reducing this bitter taste of the senescent leaves, raises the energy content by adding to the glucose and fructose levels of the leaves. This could consequently increase C. mopane’s browsable potential to game and wild animals during autumn. This could have an important impact on the game industry of the Limpopo and Mpumalanga Provinces of South Africa. / NRF (National Research Foundation) and Botany Department University of Limpopo

Thesis (M.Sc. (Molecular and Life Sciences)) --University of Limpopo, 2007 / Colophospermum mopane (sensu lato) is currently recognised on morphological and physiological characteristics. To add to the suite of taxonomic characters, the genetic variability of C. mopane (sensu lato) was investigated using the RAPD technique. DNA was extracted from young seedlings and mature leaves using the CTAB method. Initially, the DNA extraction was problematic due to the presence of polysaccharides, making PCR nearly impossible. An additional phenol precipitation step was introduced to purify the DNA used to perform RAPD analyses. Twenty random primers were tested for their suitability and reproducibility to reveal polymorphism in C. mopane (sensu lato). Nine of the primers tested amplified the genomic DNA. Subsequently, three primers (OPA 03, OPA 08 and OPA 09) were selected based on their reproducibility and demonstration of polymorphism. OPA 03 amplified most of the samples tested whereas OPA 08 and OPA 09 amplified 50% of the samples. RAPD bands ranged from 180 bp to 2000 bp. RAPD profiles of C. mopane (sensu lato) with three random primers showed few polymorphisms. Individual trees of different ecotypes show similar RAPD banding pattern, instances were found where trees of the same ecotype showed different bands. The total character difference based on presence and absence of bands revealed both variability and similarity of C. mopane (sensu lato). Phylogenetic trees from individual primers and combined primers were constructed using Neighbour Joining and Parsimony analysis. The phylogenetic tree from the combined primers of bootstrap parsimony generated three clades with low and high parsimony bootstrap values. The first clade receives weak support (61%) while the second and third clades receive support of 90% and 70%, respectively. The other remaining entities collapsed resulting in basal polytomy. The third clade shows some members of Alba (Alba 11 Phala, Alba 1 Phala and Alba 7 Musina) grouped together. The overall results of C. mopane (sensu lato) show high (84.1%) genetic similarity. No ecotypic marker was obtained. Most of the ecotypes have not diverged genetically far from one another or from the parental material (Mopane – sensu stricto). The genetic results partially support the perceived morphological differences. In this study the RAPD technique has established its value as an additional tool to express the genetic variability in C. mopane (sensu lato). / The National Research Foundation

Thesis ( M.Sc. (Biodiversity)) --University of Limpopo, 2007 / This dissertation reports on the results of field (Letsitele area) and laboratory investigations on the biology of Arytaina mopane, its ecological role as well as its physiological influences on the host plant Colophospermum mopane. The work is divided into three sections. Section one describes the various aspects of the biology of A. mopane, which includes the morphology of the eggs, nymphs and adults including the behaviour of nymphs and adults. Damage caused to the host plant by infestation as well as predation of A. mopane is discussed. Eggs are randomly laid on green and senescent C. mopane leaves, very often in clusters and along the veins. The eggs are black and conical in shape with a reticulate-sculptured membrane surrounding each. Each egg has a pedicel at the apical end and a filament at the basal end. An egg is not attached by a pedicel (contrary to the literature) but glued to the leaflet surface. Arytaina mopane exhibits an incomplete metamorphosis with the life cycle consisting of an egg, 5 nymphal instar and an adult. The five nymphal stages differed only in size and minor morphological features except for development of wings. Wingpad development is prominent from the third instars onwards. Nymphs construct scutcheon-like encrustations, commonly known as lerps over their bodies, which partly protect them from enemies and desiccation. Lerps covered only about 0.2% of the adaxial leaflet surface, where they were more common. Nymphs feed by piercing through the epidermal cells into the vascular bundle tissue of the leaflet with their stylet to reach the phloem sap. Feeding damage by nymphs results in black and reddish-brown spots on the leaflet surface. Two forms of nymphs that varied in colour and abdominal markings were identified, that could either be two different female morphotypes of the species, gender variation or natural variation. When not feeding, adults rest almost motionless on the leaflet or petiole with their stylet withdrawn and wings folded. Adults prefer walking or crawling to flying between v leaflets but sometimes jump when disturbed. When violently disturbed adults did fly short distances and returned to settle on a leaf of the same tree. The mean adult body length is 3.5 mm. In the laboratory, the life span of adults ranged between 5 and 8 days. Predators include birds such as the Red winged starling (Onychognathus morio) and Tawnyflanked prinia (Prinia subflava), the Painted reed frog (Hyperolius marmoratus taeniatus), the larvae of the Brown lacewing (Neuroptera: Hemerobiidae), a suspected Coccinellid beetle, and ants belonging to the genus Crematogaster. The second section reports on the physiological influences in terms of the chemical composition of lerps and the mineral content of both infested and uninfested C. mopane leaves. Lerps, infested and uninfested C. mopane leaves were tested for carbohydrate and mineral contents. The carbohydrate constituent of lerps and leaves (infested and uninfested) was sugar in the form of glucose, fructose and raffinose. Infested leaves contained significantly higher amounts of the macro elements calcium and magnesium than uninfested leaves. The uninfested leaves in contrast had significantly higher amounts of nitrogen, potassium, iron and copper. The ecological role of the infestation on C. mopane is reported in section three. Colophospermum mopane leaves at certain times of the year are known to have high tannin levels, which presumably results in bitter tasting leaves. The sweet encrustation (lerp) of A. mopane, apart from possibly reducing this bitter taste of the senescent leaves, raises the energy content by adding to the glucose and fructose levels of the leaves. This could consequently increase C. mopane’s browsable potential to game and wild animals during autumn. This could have an important impact on the game industry of the Limpopo and Mpumalanga Provinces of South Africa. / National Research Foundation, and the Discipline of Botany, University of Limpopo, Turfloop Campus

M.Sc. (Botany) / Please refer to full text to view abstract

Thesis (MSc. (Animal Production)) -- University of Limpopo, 2016 / A study was conducted to determine the effect of shredded Colophospermum (C.) mopane wood inclusion as roughage on performance of fattening Nguni heifers weighing 200 ± 5kg. The four diets used were isocaloric and isonitrogenous but with different shredded C. mopane wood inclusion levels of 5 (F95M5), 8.5 (F91.5M8.5), 10 (F90M10) and 15 (F85M15) %. The heifers were randomly allocated to the treatments in a completely randomized design. A quadratic equation was used to determine the shredded C. mopane inclusion levels for optimal productivity of the heifers. Shredded C. mopane wood inclusion level had effect (P<0.05) on intake and feed conversion ratio (FCR). Diet DM, OM, CP, NDF and ADF intakes per metabolic weight and FCR of Nguni heifers were optimized at different shredded C. mopane wood inclusion levels of 11.0, 13.7, 8.0, 15.0, 14.0, 14.0 and 15%, respectively. However, shredded C. mopane wood inclusion level did not affect (P>0.05) diet in vitro digestibility, carcass weight, dressing percentage, meat pH, meat shear force values and meat colour intensities except for red colour intensity of rump steak. It was, thus, concluded that shredded C. mopane wood can be used as roughage without adversely affecting diet intake, FCR, and live weight of Nguni heifers. However, diet intake and FCR were optimized at different C. mopane wood inclusion levels.

MSc (Botany) / Department of Botany

Classification of relevé data aims to present the best possible explanation of the vegetation within a specific study area. The variety of multivariate techniques available to classify vegetation into ecological communities has developed in recent years, which contributes to uncertainty among vegetation scientists as to which methods and computer software to select for optimum classification results. The wide application of the classical TWINSPAN algorithm along with the Braun-Blanquet approach of plant community descriptions and diagnostic species identification in southern Africa prompted a comparison of classification results between these classical approaches and a modern approach. The modern approach, as being referred to in this study, entails the recent improvement on the classical TWINSPAN algorithm, namely the Modified TWINSPAN algorithm in combination with statistical measures of species fidelity. Comparisons between classification end-results were undertaken at various spatial scales to test whether discrepancies between results obtained from the different approaches are similar when applied to a broad-scale synthesis, an intermediate synthesis and a local-scale classification within a similar vegetation type, the Mopaneveld. Such a comparative study is envisaged to present insight on the credibility of the use of classical approaches in phytosociology at various spatial scales. A modern approach was tested upon three previous vegetation classification studies which followed the classical approach. These vegetation classification studies were all undertaken at different spatial scales and are being referred to as the reference classifications. The data that were subjected to the modern approach were analogous to those used in the reference classifications. The computer package JUICE 7.0 was used in which the Modified TWINSPAN algorithm was applied in combination with statistical measures of species fidelity, which was obtained as a function directly in the JUICE program. Classification hierarchies were constructed for both the classical and modern approach results to compare and describe similarities and discrepancies between the different hierarchical dendrograms. Fidelity syntables were constructed to assist in the grouping of diagnostic species according to highest fidelity values. Such diagnostic species groups were compared with the lists of diagnostic species in the reference classifications. At the broadest spatial scale, comparisons revealed discrepancies between classification results from the classical and the modern approach. The modern approach presented a more robust synthesis of the Mopaneveld in southern Africa since the vegetation units and their associated diagnostic species are ecologically better expressed. The intermediate scale synthesis comparison revealed similar discrepancies, which again question the credibility of the classical approach at broader spatial scales. The application of the modern approach to the local scale classification, however, revealed little difference with the results obtained through the classical approach. Although more alternative classification techniques need to be applied to report on the most robust technique for vegetation classifications across spatial scales, it could be reported that the classical TWINSPAN algorithm is not favorable for vegetation classifications and syntheses beyond the local scale. The ecological reliability of the modern approach at the intermediate scale prompted its application in a synthesis of the riparian vegetation within the Mopane Bioregion of South Africa, which was not achieved in any previous study. Riparian vegetation plays an important role in maintaining good water quality and also provides habitat for many species. Riparian vegetation therefore needs to be classified and described. The synthesis of the riparian vegetation in the Mopane Bioregion of South Africa revealed six distinct plant communities which are described and discussed in terms of diagnostic, constant and dominant species along with variance in plant species diversity. / Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2012

Classification of relevé data aims to present the best possible explanation of the vegetation within a specific study area. The variety of multivariate techniques available to classify vegetation into ecological communities has developed in recent years, which contributes to uncertainty among vegetation scientists as to which methods and computer software to select for optimum classification results. The wide application of the classical TWINSPAN algorithm along with the Braun-Blanquet approach of plant community descriptions and diagnostic species identification in southern Africa prompted a comparison of classification results between these classical approaches and a modern approach. The modern approach, as being referred to in this study, entails the recent improvement on the classical TWINSPAN algorithm, namely the Modified TWINSPAN algorithm in combination with statistical measures of species fidelity. Comparisons between classification end-results were undertaken at various spatial scales to test whether discrepancies between results obtained from the different approaches are similar when applied to a broad-scale synthesis, an intermediate synthesis and a local-scale classification within a similar vegetation type, the Mopaneveld. Such a comparative study is envisaged to present insight on the credibility of the use of classical approaches in phytosociology at various spatial scales. A modern approach was tested upon three previous vegetation classification studies which followed the classical approach. These vegetation classification studies were all undertaken at different spatial scales and are being referred to as the reference classifications. The data that were subjected to the modern approach were analogous to those used in the reference classifications. The computer package JUICE 7.0 was used in which the Modified TWINSPAN algorithm was applied in combination with statistical measures of species fidelity, which was obtained as a function directly in the JUICE program. Classification hierarchies were constructed for both the classical and modern approach results to compare and describe similarities and discrepancies between the different hierarchical dendrograms. Fidelity syntables were constructed to assist in the grouping of diagnostic species according to highest fidelity values. Such diagnostic species groups were compared with the lists of diagnostic species in the reference classifications. At the broadest spatial scale, comparisons revealed discrepancies between classification results from the classical and the modern approach. The modern approach presented a more robust synthesis of the Mopaneveld in southern Africa since the vegetation units and their associated diagnostic species are ecologically better expressed. The intermediate scale synthesis comparison revealed similar discrepancies, which again question the credibility of the classical approach at broader spatial scales. The application of the modern approach to the local scale classification, however, revealed little difference with the results obtained through the classical approach. Although more alternative classification techniques need to be applied to report on the most robust technique for vegetation classifications across spatial scales, it could be reported that the classical TWINSPAN algorithm is not favorable for vegetation classifications and syntheses beyond the local scale. The ecological reliability of the modern approach at the intermediate scale prompted its application in a synthesis of the riparian vegetation within the Mopane Bioregion of South Africa, which was not achieved in any previous study. Riparian vegetation plays an important role in maintaining good water quality and also provides habitat for many species. Riparian vegetation therefore needs to be classified and described. The synthesis of the riparian vegetation in the Mopane Bioregion of South Africa revealed six distinct plant communities which are described and discussed in terms of diagnostic, constant and dominant species along with variance in plant species diversity. / Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2012

Mopane (Colophospermum mopane) trees are browsed upon by two key species, namely mopane caterpillars (Imbrasia belina) and African elephants (Loxodonta africana), which each inflict a different type of damage while feeding, namely defoliation (leaf removal) and pruning (branch and/or stem breakage). Damage type can have a significant influence on plant responses, and these induced changes in morphological and chemical characteristics of regrowth can influence the subsequent feeding behaviour by each species. The objective of this study was therefore partly to investigate the differential effect of defoliation by mopane caterpillars and pruning by elephants on mopane trees, and then to investigate whether these two taxonomically different species interact through their shared food resource, by looking specifically at the effect of elephant utilisation of mopane on mopane caterpillar abundance. To determine the comparative effect of each browsing type, mopane trees were subjected to simulated mopane caterpillar or elephant utilisation treatments, at various frequencies and times within the year. Regrowth characteristics were then measured on treatment and control trees, as well as on naturally utilised and unutilised trees. Reproductive investment was also recorded on naturally utilised and unutilised trees. Additionally, the impact of mopane caterpillar defoliation and elephant pruning on plant stress was investigated by measuring the level of fluctuating asymmetry (FA) in leaves. Then, to determine whether there is an interaction between elephants and mopane caterpillars, mopane caterpillar egg mass abundance in areas of high elephant impact was compared to that in areas of low elephant impact. Firstly, however, in areas without elephant damage, those tree characteristics determining host tree preference by ovipositing mopane moths were identified. From this, an understanding of how elephant utilisation may influence mopane caterpillar abundance could therefore be gained. Defoliation and pruning had a significant different effect on mopane regrowth responses. Shoot and leaf length were significantly longer on pruned trees than control trees, for both naturally utilised and simulated elephant treatment trees, while there was no difference in shoot density. Defoliation, however, resulted in shorter shoots and leaves, particularly on naturally defoliated trees, which also had leaves of a higher nutritional value (tannin:protein ratio and total polyphenolic content) than control trees. A similar increase in leaf nutritional value was recorded in areas of high elephant impact in the Kruger National Park, but not after simulated or natural elephant damage in Venetia, where natural elephant utilization was less intense. Time since damage (i.e. first versus second flush) had a significant influence on regrowth after pruning, as shoot and leaf length were significantly longer on trees flushing for the first time, while within-season timing of damage was important for defoliation, as late-season defoliation had a greater negative impact than mid-season defoliation. Late-season defoliation also had a negative effect on leaf carriage into the dry season, while pruning appeared to aid leaf retention. Reproductive investment was found to be unaffected by mopane caterpillar defoliation or elephant pruning, as mean pod density and pod mass on utilised trees was no different to unutilised trees. Defoliation also had no influence on a plant’s likelihood of flowering that same season, with flowering being determined more by tree height. Unlike pod production, however, mean leaf density was significantly reduced in the regrowth of defoliated trees, presumably due to the use of stored resources for reproduction prior to the onset of regrowth. Neither simulated nor natural defoliation by mopane caterpillars and pruning by elephants was found to affect the level of leaf FA in mopane trees, even though the degree of damage inflicted on trees was considerably higher than in studies on other species where increases in FA were observed. Mopane therefore appears to be extremely tolerant of herbivory in comparison to other species. A positive relationship between leaf nutritional value (higher protein and lower tannin and polyphenolic content) and FA was detected, but only when trees from all study areas (i.e. a wide range of environmental conditions) were considered simultaneously. Environmental conditions, rather than herbivory, therefore appear to have a greater stressing affect on mopane. In the absence of heavy elephant utilisation of mopane trees, tree size, rather than shoot length, leaf length, leaf FA or leaf nutritional value, was found to have the greatest influence on oviposition behaviour of mopane moths. Ovipositing moths showed a preference for the tall riverine habitat over the shorter woodland and scrub mopane. This preference for large trees was, however, not evident at the individual tree level, as even though egg mass number per tree was positively related to tree height, large trees were not utilised more than expected according to the available canopy volume in each size class (resource availability). Heavy elephant utilisation of mopane had a negative impact on the density of tall trees within an area, due to branch and stem breakage while feeding. Unsurprisingly then, mopane caterpillar egg mass abundance was also significantly reduced in these areas, even though the nutritional value of leaves was higher than in non-elephant impacted areas. Elephants therefore appear to have a negative effect on mopane caterpillar abundance, primarily due to their negative impact on the density of tall mopane trees. This megaherbivore and invertebrate do therefore interact through their shared food resource, mopane trees. / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted

MSCAGR (Plant Production) / Department of Plant Production / Colophospermum mopane (Fabaceae), commonly known as mopane tree, is an indigenous tree species in Southern Africa, often being the dominant species in semi-arid areas. It plays an integral part in the improvement of communities’ livelihoods when it is harvested for firewood and mopane worms which are edible insects are collected from the tree. Colophospermum mopane is host to many insects, among them Retroacizzia mopani, a leaf pest. Retroacizzia mopani produces lerps which are protective exudates that shield the insect from predation, but lerps also reduce the photosynthetic area of mopane leaves. This study aimed to determine the distribution of the African mopane psyllid, R. mopani and its natural enemies in the Tshikundamalema area, in Limpopo Province. The study assessed the presence of lerps on C. mopane, as well as determining the effect of site, tree height, tree density, tree position, branch size and neighbouring trees on R. mopani infestations at three sites. Sample of leaves infested with R. mopani were collected at six different sites and reared in the laboratory to determine the prevalence of R. mopani natural enemies and the levels of parasitism. The site, tree density, tree position, and branch size had an effect on the R. mopani infestations. The results showed that as the tree density, tree height and branch size increased, R. mopani infestation also increased. Neighbouring trees had no effect on R. mopani infestations. Trees found at the edge of the forest were more heavily infested compared to those that were inside the forest. All the three sites had low levels of parasitism by the natural enemy, Psyllaephagus arytainae Prinsloo. This indicates that P. arytainae has little effect on population dynamics of the psyllids.