Astrid Jankielsohn

Agricultural Research Council-Small Grains, South Africa · Crop Protection

The effect of habitat transformation on dung beetle assemblages in the north-western Free State was investigated by comparing the fauna of a nature reserve with that on neighboring farms. Dung beetle sampling was done in four different localities within two different habitat types, a grassveld area and a bushveld (savanna) area. In these two habita...

Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae) was recorded for the first time in South Africa in 1978. In 2005, a second biotype, RWASA2, emerged, and here we report on the emergence of yet another biotype, found for the first time in 2009. The discovery of new Russian wheat aphid biotypes is a significant challenge to the...

The incidence and host associations of Russian wheat aphid were investigated in the wheat-growing areas of South Africa from 2009 to 2011. Most Russian wheat aphid samples were collected on dryland wheat, while few samples were collected on irrigation wheat. Volunteer wheat and rescue grass were the preferred alternative host plants to cultivated w...

Meat production in South Africa is on an increasing trend. In South Africa rising wealth, urbanisation and a growing middle class means South Africans are eating more processed and high-protein foods, especially meat and dairy products. These foods are more land- and water-intensive than fruit, vegetable and grain crops, and further stress existing...

Sufficient food production for a growing human population has become an issue of global concern. Almost all of the world’s fertile land is currently in use and arable land areas cannot be expanded significantly. The global challenge is to secure high and quality yields and to make agricultural production envi-ronmentally compatible.Insects have bee...

An additional threat to sustainable food production, besides climate change, is declining biodiversity, especially in insects. To mitigate this threat, we need to determine the drivers of biodiversity decline. Insect biodiversity decline can be mainly attributed to the intensification of agriculture with the main drivers being habitat loss and use...

Emerging information on the interactions between the COVID-19 pandemic and global food systems have highlighted how the pandemic is accentuating food crises across Africa. Less clear, however, are how the impacts differ between farming systems. Drawing on 50 key informant interviews with farmers, village leaders and extension officers in South Afri...

Emerging information on the interactions between the COVID-19 pandemic and global food systems has highlighted how the pandemic is accentuating food crises across Africa. Less clear, however, are how the impacts differ between farming systems. Drawing on 50 key informant interviews with farmers, village leaders and extension officers, in South Afri...

Dung beetle activity in the soil is essential for soil health and play a vital role in any ecosystem. Diversity within a dung beetle assemblage in a particular ecosystem can indicate the sustainable functioning of this system. Monitoring the dung beetle assemblage in an area can designate the ecological status of an area. Using dung beetles can the...

Russian wheat aphid (RWA) is an international pest on wheat and occurs in most countries where large scale wheat cultivation is practiced. Consequently, considerable efforts have been made to manage RWA globally. The two management options used currently are chemical control and breeding for deployment of resistant wheat cultivars. There are howeve...

Mokhotlong and Thaba Tseka districts are major wheat producing areas in Lesotho. However, wheat yield has been declining over the past years. The purpose of this study was to investigate farmers’ cultivation practices, knowledge and management of Russian wheat aphid as possible factors for the low yields of wheat, and the capacity of extension staf...

Mokhotlong and Thaba Tseka districts are major wheat producing areas in Lesotho. However, wheat yield has been declining over the past years. The purpose of this study was to investigate farmers' cultivation practices, knowledge and management of Russian wheat aphid as possible factors for the low yields of wheat, and the capacity of extension staf...

Bread wheat is cultivated globally and is currently the major staple crop in temperate zones. After maize, wheat is the most important grain crop, cultivated in South Africa. 'Ancient' wheat landraces were cultivated commonly in the past, but are today only grown on a small area in some countries for traditional foods. Because they have been propos...

Agriculture is the cornerstone of the South African economy and farmers must ensure that they produce enough to keep up with the needs of our growing population, within the limits of nature’s increasingly constrained and over-used resources. To meet this challenge successfully we need to change our food production systems to more sustainable system...

Keywords: Russian wheat aphid; Biotypes; Distribution; Wheat area; Environment Because the Russian wheat aphid (RWA) pose a threat to the wheat industry in South Africa, it is important to understand the key factors affecting population density fluctuations in the RWA biotype complex. RWA were sampled in the wheat production regions of South Africa...

Russian wheat aphid (Diuraphis noxia) is an international wheat pest and was first recorded in South Africa in 1978 in the Bethlehem area in the Eastern Free State. Le-sotho lies adjacent to one of the largest wheat producing areas in South Africa, the Eastern Free State, where winter wheat and facultative types are cultivated under dry land condit...

Russian wheat aphid Diuraphis noxia (Kurdjumov) has spread from its native area in central Asia to all the major wheat-producing countries in the world to become an international wheat pest. Because the Russian wheat aphid is a serious threat to the wheat industry in South Africa, it is important to investigate the key factors involved in the distr...

There is currently a major gap in our understanding of early-greening in savanna trees, particularly in southern Africa. We monitored the phenology of a stand of Burkea africana and the surrounding grasses in the Nylsvley Nature Reserve, South Africa at weekly intervals over the green-up periods (August–November) between 2012 and 2014. We compared...

Russian wheat aphid was first recorded in South Africa in 1978 in the Bethlehem area in the Eastern Free State. The aphid rapidly spread to all the wheat production areas in South Africa and became a significant threat to the wheat industry in South Africa. With the release and adoption by farmers of Russian wheat aphid resistant cultivars from 199...

Biotype development jeopardizes the durability of plant resistance, which has been a cornerstone for Russian wheat aphid management. Since the first record of a new Russian wheat aphid biotype in South Africa in 2005 research in South Africa was geared towards successful development and deployment of new resistant wheat cultivars to mitigate injury...

The Russian wheat aphid (RWA) is serious pest of wheat in South Africa since its discovery in 1978. Nitric oxide (NO) plays an essential role in the RWA resistance response of wheat. This study was conducted to establish whether NO acts upstream or downstream of salicylic acid (SA) during the RWA defence response and also to investigate the effect...

Host plant resistance can effectively manage Russian wheat aphid (Diuraphis noxia) Kurdjumov (Homoptera: Aphididae) in areas where it is an economically important pest of wheat. However, biotypes of D. noxia virulent on wheat containing resistance gene Dn4 have been reported in both the United States and South Africa. Thirty wheat genotypes, includ...

The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), is one of the most economically important and widely distributed pests of wheat in the world. In 1962, D. noxia caused crop losses between 25 and 60% in the central province of Konya, Turkey. In this study, the current status of the pest in wheat-producing areas of Turkey...