South African Conditions Research Articles

Premasticating Food for Weaning African Infants: A Possible Vehicle for Transmission of HIV

Although premastication of food for weaning infants might have nutritional benefit, it is also associated with transmission of pathogens. We investigated premastication practices in Cape Town, South Africa, in lower socioeconomic status caregivers of infants below 2 years of age. A previously reported questionnaire was adapted for South African conditions. A convenience sample of infant caregivers was captured at public maternal/pediatric and HIV outpatient clinics and home visits. We interviewed 154 caregivers, 92% of whom were the biological mothers (median age: 29). Of these, 70% were black, and 29% were colored. There were 106 (69%) caregivers who practiced premastication. The median age of infants who received premasticated food was 6 (interquartile range: 4-6) months. Forty-six (43%) infants were teething, and 44 (42%) had oral mucosal lesions while receiving premasticated food. Fifty-five (52%) caregivers reported an oral condition, mostly bleeding gums, mouth sores, and thrush, and 41 (39%) caregivers reported blood in the food. Premasticating caregivers had a significantly lower educational level than those caregivers who did not engage in this practice. Premastication practices were cultural (40%), habit (20%), and on mother's advice (75%). Reasons for premastication were to pretaste (68%), encourage eating (61%), estimate food temperature (85%), and homogenize food (60%). Counselors and caregivers should be aware of the adverse effects of premastication. Education should include advice to avoid premastication and to seek health advice for oral conditions in the caregiver and child. More studies are needed to better define the extent and risks of premastication, including its possible role in increasing HIV-1 transmission.

The repellent effect of organic fatty acids on Culicoides midges as determined with suction light traps in South Africa

The efficacy of a 15% (w/w) mixture of octanoic, nonanoic and decanoic acids in light mineral oil to repel Culicoides biting midges (Diptera; Ceratopogonidae) was determined in three replicates of a 4×4 Latin square design under South African field conditions. The fatty acids were applied to ±0.07m2 polyester meshes with a mesh size 2–3mm fitted to 220V 8W Onderstepoort downdraught light traps. To reduce the relatively strong attraction of the light trap, the black light tubes in the Onderstepoort trap were replaced with 8W 23cm white light tubes. The traps were operating overnight next to cattle. Two traps treated with the mixture of fatty acids collected 1.7 times fewer midges than two untreated traps. Although this mixture of fatty acids had shown a repellent effect against a number of blood-feeding insects this is the first indication that it also has a significant repellent effect against Culicoides species and especially Culicoides (Avaritia) imicola Kieffer when applied to polyester mesh.

A case study of GM maize gene flow in South Africa

South Africa has been growing first-generation commercial genetically modified (GM) maize since 1997. Despite a requirement for non-GM food, especially for export, there is no system for coexistence of GM and non-GM crop. Gene flow is a major contributor to commingling, and different distances of cross-pollination have been recorded for maize, using a variety of field-trial designs under different environmental conditions, with the furthest distance being 650 m. However, these trials have usually been small plots and not on the scale of commercial farming. There are also no published data regarding the extent of cross-pollination for maize in South Africa, even after a decade of commercialization of GM. Thus, the aim of this study, conducted from 2005 to 2007, was to determine the extent of GM maize cross-pollination under South African conditions in the context of commercial farming practice. Field trials were planted with a central plot of yellow GM maize (0.0576 ha) surrounded by white non-GM maize (13.76 ha), in two different geographic regions over two seasons with temporal and spatial isolations to surrounding commercial maize planting. Cross-pollination from GM to non-GM maize was determined phenotypically across 16 directional transects. Pollen counts during flowering were compared to weather data as well as percentage cross-pollination. The data were transformed logarithmically, and mean percentage cross-pollination was compared to high cross-pollination. Although there was a general congruency between wind data, pollen load and cross-pollination, it is evident that wind data and pollen load do not solely explain the directional extent of cross-pollination and that swirling winds may have contributed to this incongruence. Based on the logarithmic equations of cross-pollination over distance, 45 m is sufficient to minimize cross-pollination to between <1.0% and 0.1%, 145 m for <0.1% to 0.01% and 473 m for <0.01% to 0.001%. However, compared to this, a theoretical isolation distance of 135 m is required to ensure a minimum level of cross-pollination between <1.0% and 0.1%, 503 m for <0.1% to 0.01% and 1.8 km for <0.01% to 0.001% based on high values of cross-pollination. Based on the results of this study, the use of mean values of cross-pollination over distance may result in an underestimation of gene flow. Where stringent control of gene flow is required, for example, for non-GM seed production or for GM field trials under contained use, the high values of cross-pollination should be used to determine isolation distance. However, this may not be practical in terms of the isolation distance required. We therefore suggest that temporal and distance isolations be combined, taking into account the GM maize pollen sources within the radius of the most stringent isolation distance required.

Theoretical energy calculations for food processing under South African conditions

Accurate information regarding the energy requirements for the processing of food products will allow better application of energy saving measures and reduction of carbon emissions. Theoretical energy usage calculations for the production, under South African conditions, of two hundred different food products, some under varying process conditions have been developed and compared with theoretical and practical data in the literature.. Each calculation in spreadsheet format involves a flow diagram of the process and a mass and energy balance. Thus the results given are: a) the theoretical product yield, b) the approximate total energy requirement in kJ kg-1 and c) the energy requirement, either electrical or thermal, of each stage of the process. The individual steps have been, where possible analysed using standard theoretical methods. Empirical methods and data from equipment manufacturers have been used where standard methods are not readily available. The theoretical results indicate lower but similar energy use than other surveys and practical tests available in the literature. Comparisons are difficult because of variation in the scale of the processes and the process boundaries. An arithmetic mean taken over the 300 spreadsheets indicates that 80% of energy usage is thermal. Benchmark energy usages are indicated from these results. In addition each calculation highlights the unit operations within the production sequence which could be addressed to reduce both the energy usage and the carbon emissions. Examples of the utilisation of the results are given. The methods used are applicable to other products and other operating conditions.

Comparative performance of tomato cultivars cultivated in two hydroponic production systems

Cultivar selection for different hydroponic production systems is an important management decision, potentially impacting the tomato grower’s profitability. Knowledge on the performance of tomato cultivars, in specific hydroponic systems (open-bag and closed system) under South African conditions, is still very limited. The performance of four cultivars was evaluated in an open and a closed hydroponic (gravel-film technique) system. The commonly grown cultivars evaluated in each of the two hydroponic systems were ‘FA593’, ‘Malory’, ‘Miramar’ and ‘FiveOFive’. For each experiment a randomized complete block design was used with four replicates. Total, marketable and unmarketable yields, as well as internal fruit quality characteristics (total soluble solids (°Brix) and pH) were determined. Although no significant differences in total yield could be established - neither in the open nor in the closed hydroponic system - differences in marketable yield were observed. ‘Miramar’ and ‘Five-OFive’ produced the highest marketable yield in the closed system; the high unmarketable yield of ‘FA593’ and ‘Malory’ in the closed hydroponic system could be attributed to the high number of cracked fruit due to their inherent larger fruit size. There were no significant differences in °Brix between cultivars in the closed system. Cultivar ‘FiveOFive’, ‘FA593’ and ‘Miramar’ produced higher marketable yields than cultivar ‘Malory’ when grown in the open-bag system. ‘Malory’ and ‘FA593’ produced the highest number of fruit exhibiting fruit cracking in the open bag system. In the open system, only cultivar ‘Malory’ had a higher °Brix than ‘Miramar’ and ‘FiveOFive’. The most promising cultivars for local hydroponic tomato production, with regard to yield and quality, were identified as ‘Miramar’ and ‘FiveOFive’, with ‘FA593’ performing equally in the open system only. Further studies need to be undertaken on economical comparison of the two production systems.

Constraints on investment weights: What mandate authors in concentrated equity markets such as South Africa need to know

ABSTRACTThis article demonstrates the importance of setting risk budgets and constraints mindful of the nature of the chosen benchmark and the investment environment. The asymmetrical inefficiency of the long-only constraint when applied to a concentrated investment environment such as the South African equities market is illustrated. We estimate the optimal distribution of investment weights in each security in the context of standard portfolio construction techniques and typical South African equity benchmarks and market conditions. These distributions provide guidance to mandate authors who are considering allowing limited shorting in their net long portfolios as to the amount of gearing that is likely to be required. These estimates also show authors of long-only mandates the circumstances and assets for which their restrictions are materially binding.

Prophylactic human papillomavirus vaccination against cervical cancer: a summarised resource for clinicians

The South African Human Papillomavirus Advisory Board was established in August 2005 as an independent advisory group of clinicians and scientists, considered to be opinion leaders in the field of gynaecological oncology and cervical cancer epidemiology and screening. The Board is affiliated to SASOG and SASGO and is supported logistically by several companies with an interest in HPV-related disease. The members of the Board do not declare any conflict of interest. The opinions and recommendations expressed in this document do not reflect the policy of any company or the opinion of any individual board member, and is not meant to be prescriptive or legally binding.These guidelines are intended and presented as summarised information for health care providers and managers, interpreted with South African data and conditions in mind, on which to base clinical decision making. This document represents the first major revision of the vaccine document published in 2008 and will continue to be revised. For the r...

Application of artificial mussels (AMs) under South African marine conditions: A validation study

Over the last three decades there has been a significant decline in the number of marine pollution monitoring-related studies in South Africa. Thus, the current study was conducted to assess the current state of metal contamination within the South African marine environment through the validation of the artificial mussel (AM). Indigenous reference mussels (Perna perna) were deployed alongside the passive device within the South African marine environment for a 6week exposure period. Analysis of metal uptake (Cd, Cr, Cu, Pb and Zn) was determined by filtration and elution of the AM chelex resins, microwave digestion of the transplanted mussels, and determination of their metal concentrations by ICP-MS and ICP-OES analysis. Uptake patterns between the AM and transplanted mussels showed significant temporal and spatial correlation for the majority of the elements analysed. While the AM provided relevant and complementary information on the dissolved metal concentrations, limitations were also observed.

The use of filter media to determine filter cleanliness

It is general believed that a sand filter starts its life with new, perfectly clean media, which becomes gradually clogged with each filtration cycle, eventually getting to a point where either head loss or filtrate quality starts to deteriorate. At this point the backwash cycle is initiated and, through the combined action of air and water, returns the media to its original perfectly clean state. Reality, however, dictates otherwise. Many treatment plants visited a decade or more after commissioning are found to have unacceptably dirty filter sand and backwash systems incapable of returning the filter media to a desired state of cleanliness. In some cases, these problems are common ones encountered in filtration plants but many reasons for media deterioration remain elusive, falling outside of these common problems.The South African conditions of highly eutrophic surface waters at high temperatures, however, exacerbate the problems with dirty filter media. Such conditions often lead to the formation of biofilm in the filter media, which is shown to inhibit the effective backwashing of sand and carbon filters. A systematic investigation into filter media cleanliness was therefore started in 2002, ending in 2005, at the University of Johannesburg (the then Rand Afrikaans University). This involved media from eight South African Water Treatment Plants, varying between sand and sand-anthracite combinations and raw water types from eutrophic through turbid to low-turbidity waters.Five states of cleanliness and four fractions of specific deposit were identified relating to in situ washing, column washing, cylinder inversion and acid-immersion techniques. These were measured and the results compared to acceptable limits for specific deposit, as determined in previous studies, though expressed in kg/m3. These values were used to determine the state of the filters. In order to gain greater insight into the composition of the specific deposits stripped from the media, a four-point characterisation step was introduced for the resultant suspensions based on acid-solubility and volatility.Results showed that a reasonably effective backwash removed a median specific deposit of 0.89kg/m3. Further washing in a laboratory column removed a median specific deposit of 1.34kg/m3. Media subjected to a standardised cylinder inversion procedure removed a median specific deposit of 2.41kg/m3. Immersion in a strong acid removed a median specific deposit of 35.2kg/m3.The four-point characterisation step showed that the soluble-volatile fraction was consistently small in relation to the other fractions. The organic fraction was quite high at the RG treatment plant and the soluble-non-volatile fraction was particularly high at the BK treatment plant.

Developments in undergraduate wood science education at Stellenbosch University, South Africa

In South Africa, Stellenbosch University (SU) is the designated provider of Bachelor, Master and Doctorate level qualifications in Forestry and Wood Products Science. SU provides educational programs to both mechanical (sawmilling, preservation, composite products, furniture, etc.) and the chemical (pulp & paper) processing sectors. To ensure academic quality, SU regularly has her academic programs assessed externally. In 2000, several changes to the then existing 4 year B.Sc. Wood Science program were recommended. A restructured SU undergraduate program, similar to the B.Sc. Wood Products Processing program at the University of British Columbia (UBC), Vancouver, Canada, was consequently introduced in 2003. That same year, to provide more support to this effort, a partnership between UBC, SU and the Nelson Mandela Metropolitan University, the SA institution responsible for the National Diploma and Bachelor of Technology degrees in similar subjects, was established. The objective was to develop and deliver successful tertiary programs in value-added wood product processing education for South Africa and later, for other African countries as well. A Wood Products Processing Education Project, implemented in 2004 and running until mid 2010, funded by the respective partner institutions and the Canadian International Development Agency (CIDA) through the University Partnership in Cooperation and Development Program, was established. In addition to curriculum developments based on the UBC model, module content was modified to address relevant South African conditions. To make modules accessible to part-time students and members of industry off-campus, conversion of several Wood Products Science modules into e-learning format was implemented. A concise overview of Wood Science education at Stellenbosch University is given and the implementation and progress of the CIDA project at SU is briefly discussed. Solutions to the educational needs of the SA pulp & paper sector are also highlighted.

Developing a South African pedestrian environment assessment tool: Tshwane case study

Pedestrians, comprising approximately 60% of the population, are among the most vulnerable road users in South Africa. The roadside environment may be an important factor influencing the nature and frequency of pedestrian fatalities. While there are audit tools for assessing the pedestrian environment in other countries, no such tool exists for South Africa. This study evaluated existing audit tools in relation to South African issues and conditions and developed a South African Pedestrian Environment Assessment Tool (PEAT). PEAT was tested at five sites in the Tshwane Metropolitan Area in Gauteng to assess its applicability. PEAT was simple to use and provided valuable information, however, appropriate measures need to be taken to address fieldworker security, especially for night-time assessments when several roadside factors, such as lighting, should be evaluated. Although it was not the focus of our study, based on our results, we suggest that the lack of pavements, pedestrian crossings and pedestrian lighting are factors that, potentially, could increase pedestrian vulnerability.

Comparison of the effects of different transport conditions and lairage times in a Mediterranean climate in South Africa on the meat quality of commercially crossbred Large white x Landrace pigs

Information on the effect of road transportation conditions and lairage times on the meat quality of pork under South African conditions is very sparse. In this investigation, the effects of 2 road conditions (rough road with frequent stops - A; smooth road, few stops - B) and 2 lairage holding periods (2 h and 24 h) on the physical meat quality attributes of commercially produced pigs during summer (ambient temperatures > 30 degrees C) in the Western Cape (South Africa) were investigated. Pig meat from pigs transported on a road that caused more stress (A), had lower pH 45 (measured 45 min post mortem) values after 2 h lairage than pigs transported over a smoother road. Pigs B had a lower muscle pH 24 (measured 24 h post mortem) than group A, indicating that they had more glycogen reserves available for post mortem glycolysis. Road conditions A were more stressful resulting in a higher incidence of PSE pork, as shown by the percentage drip loss and the L* values. When the lairage period was increased to 24 h prior to slaughter, pigs transported under road conditions A had time to replenish their energy reserves and the pH 45, drip loss and L* values were within an acceptable range. However, pigs transported under road conditions B had lower pH 45 and higher pH 24 values, indicating that the lairage period was too long and that energy reserves were depleted in order to adapt to the stressful conditions. Results from this investigation indicate that improvement of the transport/road conditions will result in better pork quality.

Evaluation of PCR assays for the detection of Campylobacter fetus in bovine preputial scrapings and the identification of subspecies in South African field isolates

As a result of the high lability and slow growth of Campylobacter fetus subspecies, the laboratory diagnosis of bovine genital campylobacteriosis has always been difficult. This is especially true under South African conditions, where farms are far apart, laboratories are only present in major centres and there are high ambient temperatures. In order to overcome the shortcomings associated with traditional diagnostic methods, the implementation of a molecular assay was sought. This work describes how a previously published PCR assay (MG3F/ MG4R primers) was adapted, optimised and applied in the diagnostic laboratory to test preputial samples directly for the presence of Campylobacter fetus. Field evaluation of the assay revealed an analytical sensitivity and specificity of 85.7% and 99%, respectively. Subsequent genotyping and phenotyping of a diverse collection of South African field isolates revealed that South Africa has an unexpected and previously unreported high incidence of Campylobacter fetus subsp. venerealis biovar intermedius strains. These strains were not identified correctly by the subspecies-specific primer set evaluated. Until such time that cost- effective genotyping methods are available to diagnostic laboratories in South Africa, and other countries with these atypical Campylobacter fetus subsp. venerealis strains, the need for bacterial culture will persist. Identification to subspecies level of isolates at present remains dependent upon a single phenotypic criterion, namely tolerance to 1% glycine.

Avian collisions with power lines: a global review of causes and mitigation with a South African perspective

SummaryMany large terrestrial and wetland birds and some smaller, fast-flying species are prone to colliding with overhead wires associated with power infrastructure. A high proportion of these are threatened species and for some, collision with power lines and other man-made structures is a significant and damaging source of anthropogenic mortality. We review the existing literature on the nature, scale and impact of this problem worldwide, with particular emphasis on the South African situation, and focus on the evidence for and against various line configurations and devices proposed to mitigate the negative effects of overhead lines on bird populations. Cranes, bustards, flamingos, waterfowl, shorebirds, gamebirds and falcons are among the most frequently affected avian groups, and collision frequency is thought to be an influential factor in ongoing population declines in several species of cranes, bustards and diurnal raptors. The bulk of the research on this issue has been done in North America, Scandinavia, southern Europe and South Africa. Few comprehensive experimental studies on ways to reduce avian collisions with power lines have been carried out, although most of these have yielded quite clear results. Mitigation options considered include reviewing the placement of proposed new lines, removing the earth-wire which is usually the highest, thinnest and most problematic component in an overhead power line configuration, or else fitting this wire with markers – brightly coloured ‘aviation’ balls, thickened wire coils, luminescent, shiny or hinged flashing or flapping devices. All of these options reduce bird collision frequency overall by at least 50–60%, although the efficacy of line marking may be much lower for certain species (e.g. bustards). There remains considerable uncertainty about the best-performing marking device (perhaps because performance may vary with both local conditions and the species involved in each instance), and a durable, all-purpose device, that is effective both during the day and at night, has not yet been developed. We conclude by outlining a proposed experimental evaluation of the full array of collision mitigation options, to select the best approaches for use under South African conditions.

A spatial assessment of &lt;i&gt;Brassica napus&lt;/i&gt; gene flow potential to wild and weedy relatives in the Fynbos Biome

Gene flow between related plant species, and between transgenic and non-transgenic crop varieties, may be considered a form of biological invasion. Brassica napus (oilseed rape or canola) and its relatives are well known for intra- and inter-specific gene flow, hybridisation and weediness. Gene flow associated with B. napus poses a potential ecological risk in the Fynbos Biome of South Africa, because of the existence of both naturalised (alien, weedy) and native relatives in this region. This risk is particularly pertinent given the proposed use of B. napus for biofuel and the potential future introduction of herbicide-tolerant transgenic B. napus. Here we quantify the presence and co-occurrence of B. napus and its wild and weedy relatives in the Fynbos Biome, as a first step in the ecological risk assessment for this crop. Several alien and at least one native relative of B. napus were found to be prevalent in the region, and to be spatially congruent with B. napus fields. The first requirement for potential gene flow to occur has thus been met. In addition, a number of these species have elsewhere been found to be reproductively compatible with B. napus. Further assessment of the potential ecological risks associated with B. napus in South Africa is constrained by uncertainties in the phylogeny of the Brassicaceae, difficulties with morphology-based identification, and poor knowledge of the biology of several of the species involved, particularly under South African conditions.

Effect of nitrogen levels and sources on production of Swiss Chard (Beta vulgaris var. Cicla)

To optimise the production of Swiss chard, high levels of nitrogen fertiliser are often applied. This may have adverse effects on both the economy of fertilisation and the nutritional value of the human diet. Very little is known about both the optimum levels and influence of different sources of nitrogen on this crop under South African conditions. Glasshouse experiments were therefore conducted to determine the integrated effects of nitrogen level and source on the yield and quality of Swiss chard. Three Swiss chard seedlings were planted in each 4 L pot and later thinned to one plant per pot. Nine nitrogen levels (0, 100, 200, 300, 400, 500, 600, 700 and 800 kg ha-~ N) and six nitrogen sources (ammonium nitrate, calcium nitrate, potassium nitrate, ammonium sulphate, urea ammonium nitrate and urea) were combined in a factorial arrangement with four replications. The number of leaves harvested, leaf area, fresh and dry leaf mass, and leaf nitrogen content increased with increasing nitrogen levels up to 800 kg ha-~ N. Dry leaf mass was significantly higher where urea was applied compared to calcium nitrate. Although the different nitrogen sources did not differ significantly at the corresponding application levels, the nitrate accumulation within Swiss chard leaves was significantly increased with the use of ammonium nitrate.

An overview of the context and scope of wheat (Triticum aestivum) research in South Africa from 1983 to 2008

The domestic requirement for wheat in South Africa is approximately 2.8 million tons and annually the shortfall on local production is imported to meet the demand. During the past 25 years two distinct wheat marketing mechanisms characterised the wheat industry, impacting significantly on both research and industry. In 1996 the single channel marketing system through the Wheat Board made way for a liberal marketing environment in which market forces of supply and demand determine price. This refocused most research activities on factors to lower input costs and risks, while increasing the profitability of wheat production. Significant challenges were experienced with much stricter milling and baking quality requirements impacting on not only the development of adapted wheat cultivars for South African conditions, but also on fertiliser and cultivar recommendations, as well as production practices. Minimum tillage, preharvest sprouting, as well as the threat of Russian wheat aphid and stripe rust were some of the pertinent challenges faced during this time. Significant scientific breakthroughs of international importance were made with regard to the physiological and biochemical nature of insect resistance and plant defence as well as the transfer of resistance genes from alien species. This review provides an overview of the most pertinent wheat research undertaken from 1983 to 2008.

Initiation and First Results of a Biofortification Program for Sweet Potato in South Africa

Orange-fleshed sweet potato, high in provitamin A carotenoids, were introduced to Africa from the United States, but there was a shortage of varieties with desirable traits for South African conditions, namely, stable yield, good total carotenoid content, and good taste. Desirable characteristics were combined annually through the polycross method using parents selected for specific traits, followed by clonal selection phases and multi-location advanced yield trials. Genotype by environment analysis of advanced lines indicated two locally bred lines, 1998-21-1 (released as “Impilo”) and 1999-1-7, as the best. Other useful clones were 1999-6-1 (released as “Khano”) and U.S. variety “Resisto.” These were recommended for use in food-based approaches to address vitamin A deficiency. In addition, three new promising lines were identified, viz., 2001-5-2, 2000-6-1, and 2000-10-7, which needed to be evaluated in multi-location trials to determine their adaptability. Future breeding efforts could concentrate on higher levels of total carotenoids and stable high yields, and in addition, on tolerance to drought and Alternaria stem blight.

Duration of repellency of N,N-diethyl-3-methylbenzamide, citronella oil and cypermethrin against Culicoides species when applied to polyester mesh

The repellent efficacy of 15% N,N-diethyl-3-methylbenzamide (DEET), 0.6% citronella oil, and 0.3% α-cyano-cypermethrin against Culicoides species was compared in three 5×5 Latin squares (15 replicates) under South African field conditions. DEET, citronella oil or α-cyano-cypermethrin were applied to polyester meshes that were fitted to down-draught suction 220V UV light traps which were operated overnight. No significant repellent effect against Culicoides was found for the citronella oil or the α-cyano-cypermethrin. DEET had a significant repellent effect against Culicoides species and C. imicola for all catches made from after sunset to before sunrise.

Comparaison de pièges à &lt;em&gt;Culicoides&lt;/em&gt; en Afrique du Sud

The primary monitoring tools for collecting Culicoides midges (Diptera: Ceratopogonidae) are various models of light traps. To facilitate data comparison, four downdraught light traps were used in summer under South African conditions. These were the Onderstepoort trap [220 V, ultraviolet (UV)], the Rieb trap (12 V, UV) from France, the mini-CDC trap (6 V, UV) from the USA , and the Pirbright trap (220 V, white light) from the United Kingdom. Traps were deployed in three replicates of a 4x4 randomized Latin square design, so that treatment means were independent of any effects caused by the site or the occa­sion. Trapping was conducted during 12 nights in January 2008 (summer) and comprised 48 collections with 643,374 Culicoides midges collected. Eighteen different Culicoides species, of which only six were found in all four traps, were collected. All four traps indicated Culicoides imicola to be the most abundant species. Its abundance ranged from 91.8% (Rieb) to 95.0% (Onderstepoort). Statistically significant differences were found in the total number of Culicoides collected by each of these traps. The Onderstepoort trap (407,411) collected statistically significantly more midges than the CDC (167,794), Pirbright (39,128) or Rieb trap (32,041). Significant differences were also found between the traps in the parous rate, sex ratio and number of Culicoides midges compared to those of other insects. When comparisons were repeated in winter, when Culicoides numbers were relatively low compared to summer, the Onderstepoort trap still performed significantly better. All four traps, however, still captured Culicoides midges. In addition, the BG-sentinel mosquito trap, from Germany, was compared with the other four traps in two replicates of a 5x5 Latin square. These com­parisons, which were done in spring, showed that the number of Culicoides midges collected with the BG-sentinel was not significantly different from that collected with the CDC trap. Although the Onderstepoort trap increased monitoring sensitivity in areas where vector abundances were low, results highlighted the notion that biases in trapping methods need to be evaluated and measured.