The status of fall armyworm pests in maize in South Africa varies between the Lowveld region, the Highveld region and other areas such as the Eastern and Western Cape provinces, where sporadic infestations are expected late in the planting season. So there is potential for biological control to be part of an integrated pest management (IPM) system for fall armyworm in South Africa.
Genetics to the fore
Identifying a QTL
To link this genetic information to FCR resistance, the disease scores for each plant in the population are needed. Viruses are also self-replicating organisms, which allows them to spread within host populations and persist in the environment for long periods of time.
Viruses as
Viruses are generally seen as an enemy of the people, and with good reason, given the often devastating outcomes of viruses such as the COVID-19 coronavirus, Ebola and HIV, and the nuisance of rhinoviruses, responsible for the common cold. Compared to most chemical insecticides, field application of virus-based biopesticides is much less detrimental to our beneficial insects, such as bees and parasitoids, due to their narrow host range.
One of these projects is exploring the beneficial effects of combining virus with yeast. One of the most recent developments in CBC and VRG was the discovery of the virus species, CrpeNPV.
The false codling moth
For nearly two decades now, this virus has been successfully used in the field to control false codling moth in South Africa. These challenges led to the initiation of several new projects, each aimed at improving aspects of this virus to ensure its continued use in the field. Experiments carried out with the false codling moth and yeast isolated from the field have already shown that they prefer fruit sprayed with yeast over those without.
Additionally, the combination of the virus with yeast has resulted in a higher level of pest control than when used alone. This virus was isolated from the lychee moth, a major pest of lychee in South Africa.
Bats versus
The research team at the University of Venda decided to use fluorescently labeled primers to show the presence of four of the most important insect pests in bat faecal pellets: the two-spotted stink bug (Bathycoelia distincta), the green vegetable bug (Nezara viridula), the macadamia. Interestingly, all the species or families of bats from which pellets were collected fed on at least one of the four main insect pests, and pests were found in more than half of the samples. As part of the project, bats and birds were also excluded from macadamia trees by erecting cages around the trees.
The shift in distribution and target species is largely attributed to a lack of natural predators, but has also prompted questions about the role climate change may play. Feeding damage by cosid moth larvae causes blackening and weakening of the tree trunk.
Remote sensing to the rescue
The algorithm was 'trained' using 70% of the attendance data, while the remaining 30% was used to test the model's performance. The compartments sampled during the field survey are shown on a false color composite of the multispectral Sentinel-2 image, using bands 4 (red), 8 (near infrared) and 2 (blue). Among the spectral bands, the red edge band 5 was the most influential in the modeling process, while the Photosynthetic Vigor Ratio (PVR) was the most important among the vegetation indices.
The model output revealed some areas with a high probability of the pest's occurrence where it was not detected during the field survey, confirming that the method provides a faster and more accurate way to improve pest monitoring in plantations, and can play an important role in supporting forestry management strategies. The use of Sentinel-2 multispectral imagery to map the occurrence of the cossid moth (Coryphodema tristis) in Eucalyptus nitens plantations of Mpumalanga, South Africa.
Nanotechnology
What is Nanotechnology?
Applications of Nanotechnology
Nanotechnology in Energy
Nanotechnology in Medicine
Dr Phuti Chelopo -
Nanomedicine Researcher
- What influenced you to pursue this career path and why did you choose it?
- What average marks in matric (science and mathematics) are required to study a degree at a university?
- What qualification does one need to pursue nanotechnology as a career, and what courses should one major in at a
- What would you say is fulfilling about your career and which three words describe your occupation?
The field of nanotechnology and nanoscience has grown as a result of improved understanding of the characteristics of nanomaterials, the relationship between nanostructures and properties, and how they are manipulated. My PhD project involved the use of nanotechnology to improve the current treatment regimen for tuberculosis. Before my PhD studies, I developed an interest in the impact of nanotechnology to solve societal problems and having the opportunity to be involved in it made me feel fulfilled.
Nanomedicine is the application of nanotechnology to make devices or systems for medical application at the nanometer scale (1 to 100 nm). Therefore, with the right skills, there is great potential to grow in the field of nanotechnology.
Small science
Called SA NanoSchool 2019, it was run by the Nanoscience Center at the University of the Western Cape, which is part of the National Nanoscience Postgraduate Teaching and Training Platform (NNPTTP), funded by the Department of Science and Innovation (DSI). They complement existing human capital development programs on the ground and form one of the many platforms for the implementation of the National Nanotechnology Strategy 2005. Nicklaus Kruger is a writer focusing on education, health and science in the media section of the University of the Western Cape.
The DNA Sequencing Unit at Stellenbosch University's Central Analytical Facilities (CAF) uses the rapid DNA sequencing method that was used to sequence the first human genome. Bacteria were isolated from different sections of the gastrointestinal tract of healthy free-range broilers, identified to species level using Sanger sequencing on CAFs, and then screened for probiotic properties.
CURRICULUM CORNER
What are phytoliths?
Although caution should be exercised in interpreting such data from archaeological sites for past environmental constructions – as they often represent human choices in plant use – plants found in the archaeological record are generally thought to be representative of the type plants that were available in the surrounding vegetation. Our understanding of the archaeological phytolith record is based on analogies with phytoliths found in modern plants. As a first step toward researching fossil phytoliths at Bushman Rock Shelter, Dr. Aurore Val and I therefore collected modern plant specimens (wood and tree leaves) and soils that occurred in the area in late winter 2017.
In the summer of 2018, several plant samples from both grass and trees were collected with the help of Dr. Christine Sievers. Fossil phytoliths have been recovered from several of the archaeological sediments by treating them with acids.
Bushman Rock Shelter
Amanda Mahlangu, a master's student in chemistry at the University of Pretoria (UP), won an award for the best student paper presented at the 2019 National Clean Air Association Conference, held in Stellenbosch in October. The results of the study will contribute to our understanding of ground-level ozone and secondary organic aerosol (SOA) - both pollutants that affect human health and ecosystems. Receiving the award is a great honor as it would mean recognition of the hard work I have put into my project, from highly knowledgeable professionals in my field and in the scientific community," Mahlangu said excitedly about the award.
This motivated me to continue to work hard and strive to grow in my field.” After her undergraduate studies, she went on to graduate with an honors degree in chemistry in 2017.
Chemistry for clean air
Her presentation was entitled “Characterization of semi-volatile hydrocarbon emissions from diesel engines” and was based on a study in which she analyzed diesel exhaust emissions. I've always loved chemistry from a young age and was quite good at it in high school, so the choice to do it at the university level was almost an obvious choice. Completing the degree was not an easy task, but winning this award felt like confirmation that I had made the right decision and that – despite the challenges – following my passion was the best choice I could have made for myself .”
Mahlangu completed a bachelor's degree in biochemistry, majoring in both biochemistry and chemistry, and it was during these years that she developed her passion for scientific research and analytical chemistry. A year later, she began her master's degree and joined the Environmental Monitoring and Sensing Research Group led by Prof.
Africa’s first PhD in
BIOPHOTONICS
As a result of this challenge, the biophotonics group conducts research with light in the form of femtosecond laser to deliver drugs to specific cells. The signal generated comes from the changes in the refractive index at the surface of the sensor chip. LLLT uses light within the red (visible light) and near-infrared regions of the electromagnetic spectrum, in the wavelength range 600–.
In the biophotonics group, Raman spectroscopy research focuses on both disease diagnosis and screening of medicinal drugs as a means of performing quality assurance. Stem cells are basic cells that can become almost any type of cell in the body.
UJ take top spots at 3MT
Two postgraduate students from the University of Johannesburg (UJ) went one-two in the national Three Minute Thesis (3MT) competition in October, taking first and second place. Martin Bekker, from the UJ Center for Sociological Research, was declared the overall winner for his presentation entitled "Everything I thought about the protest was wrong" and was awarded 16 000 RON in cash. His presentation video was then submitted to the Universitas 21 3MT international competition, which was ultimately won by a student from the University of Queensland.
I looked at the largest data set of its kind in the world, which happens to be from the South African Police Service that attends every mob incident, and I used machine learning processes to read 150,000 records.” Pertunia Mashile, from UJ's Department of Chemical Sciences, was awarded R13 000 as her second place prize, but also won the People's Choice Award for her presentation entitled 'Can what is useful be harmful?'.
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