Browsing Research Output by Author "Van den Berg, Johnnie"
Now showing items 1-20 of 24
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Assessing the likelihood of gene flow from sugarcane (Saccharum Hybrids) to wild relatives in South Africa
Snyman, Sandy J.; Komape, Dennis M.; Khanyi, Hlobisile; Van den Berg, Johnnie; Cilliers, Dirk; Barnard, Sandra; Siebert, Stefan J. (Frontiers Media, 2018)Pre-commercialization studies on environmental biosafety of genetically modified (GM) crops are necessary to evaluate the potential for sexual hybridization with related plant species that occur in the release area. The ... -
The charismatic praying mantid: a gateway for insect conservation
Greyvenstein, Bianca; Du Plessis, Hannalene; Van den Berg, Johnnie (Taylor & Francis, 2020)Praying mantids (Mantodea) are not only apex predators with a ‘mystical’ status, but are also regarded as a kind of oracle and, in some cultures, as omens associated with good or bad. In the future, the cultural, mystical ... -
Detection of transgenes in local maize varieties of small-scale farmers in Eastern Cape, South Africa
Iversen, Marianne; Van den Berg, Johnnie; Grønsberg, Idun M.; Fischer, Klara; Aheto, Denis Worlanyo (Public Library of Science, 2015)Small-scale subsistence farmers in South Africa have been introduced to genetically modified (GM) crops for more than a decade. Little is known about i) the extent of transgene introgression into locally recycled seed, ii) ... -
Distribution of Galepsus spp. in Southern Africa and life history of Galepsus lenticularis (Mantodea: Tarachodidae)
Greyvenstein, Bianca; Du Plessis, Hannalene; Van den Berg, Johnnie; Moulin, Nicolas (MDPI, 2020)Galepsus Stäl is a genus within the Mantodea and has hardly been studied in Africa. The distribution of the Galepsus genus in Southern Africa was established, based on insect collection records, and the biology of Galepsus ... -
Diversity and comparative phenology of lepidoptera on Bt and non-Bt maize in South Africa
Van Hamburg, Huib; Van den Berg, Johnnie; Van Wyk, Annemie (Taylor & Francis Group, 2008) -
Diversity of fall armyworm, Spodoptera frugiperda and their gut bacterial community in Kenya
Gichuhi, Joseph; Van den Berg, Johnnie; Du Plessis, Hannalene; Sevgan, Subramanian; Khamis, Fathiya (PeerJ, 2020)Background The invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) is a polyphagous pest that causes widespread damage particularly to maize and sorghum in Africa. The microbiome associated with S. frugiperda could ... -
Diversity patterns of plants and arthropods in soybean agroecosystems in the grassland biome of South Africa
Janse van Rensburg, Paul Duvel; Siebert, Stefan John; Ellis, Suria; Van den Berg, Johnnie; Masehela, Tlou (Smujo, 2020)Soybean is widely cultivated in the grassland biome of South Africa (ca. 800 000 ha per annum). Yet the possible effects that large-scale cultivation of soybean has on biodiversity in adjacent habitat are not fully ... -
Dominant inheritance of field–evolved resistance to Bt corn in Busseola fusca
Campagne, Pascal; Kruger, Marlene; Van den Berg, Johnnie; Pasquet, Rémy; Le Ru, Bruno (Public Library of Science, 2013)Transgenic crops expressing Bacillus thuringiensis (Bt) toxins have been adopted worldwide, notably in developing countries. In spite of their success in controlling target pests while allowing a substantial reduction of ... -
The effect of different host plants on development and survival of Nysius natalensis (Hemiptera: Orsillidae)
Du Plessis, Hannalene; Van den Berg, Johnnie; Byrne, Marcus (Oxford University Press, 2015)Nysius natalensis Evans (Hemiptera: Orsillidae) is a pest of sunflower in South Africa. Adults invade sunflower fields from their weedy hosts. The host plant suitability for development and survival and the effect of ... -
Effects of Cry1Ab transgenic maize on lifecycle and biomarker responses of the earthworm, Eisenia Andrei
Van der Merwe, Frances; Bezuidenhout, Carlos; Van den Berg, Johnnie; Maboeta, Mark (MDPI, 2012)A 28-day study was conducted to determine the effects of the Bacillus thuringiensis Cry1Ab toxin on the earthworm Eisenia andrei. Previously, investigations have been limited to life-cycle level effects of this protein ... -
Historic distribution and life history of the African twig mantid, Popa spurca (Mantodea: Deroplatyidae) in southern Africa
Greyvenstein, Bianca; Du Plessis, Hannalene; Van den Berg, Johnnie (Taylor & Francis, 2020)(Stål) (Deroplatyidae) is a well-known species within the African Mantodea. Because this species is often kept as pets, several citizen-based platforms provide information on the rearing of this species. There is however ... -
Humoral and cellular immune responses in mice after airway administration of Bacillus thuringiensis Cry1Ab and MON810 cry1Ab–transgenic maize
Andreassen, Monica; Van den Berg, Johnnie; Rocca, Elena; Bøhn, Thomas; Wikmark, Odd-Gunnar (Taylor & Francis, 2015)Genetically modified (GM) crops may bring new proteins with immunogenic and allergenic properties into the food and feed chains. The most commonly grown GM maize, MON810, expresses a modified version of the insecticidal ... -
Introgression of a cry1Ab transgene into open pollinated maize and its effect on Cry protein concentration and target pest survival
Erasmus, Reynardt; Pieters, Rialet; Du Plessis, Hannalene; Van den Berg, Johnnie; Hilbeck, Angelika (Public Library of Science, 2019)In Africa, the target pests of genetically modified Bt maize are lepidopteran stem borers, notably Busseola fusca (Lepidoptera: Noctuidae). Gene flow between Bt maize hybrids and open pollinated varieties (OPVs) that do ... -
Molasses grass induces direct and indirect defense responses in neighbouring maize plants
Tolosa, Tigest A.; Van den Berg, Johnnie; Khan, Zeyaur R.; Tamiru, Amanuel; Midega, Charles A.O. (Springer, 2019)Plants have evolved intricate defence strategies against herbivore attack which can include activation of defence in response to stress-related volatile organic compounds (VOCs) emitted by neighbouring plants. VOCs released ... -
Napier grass stunt disease in East Africa: farmers' perspectives on disease management
Asudi, George O.; Van den Berg, Johnnie; Khan, Zeyaur R.; Midega, Charles A.O.; Pittchar, Jimmy (Elsevier, 2015)Napier or Elephant grass (Pennisetum purpureum), the most important livestock fodder crop in East Africa, is under threat from Napier grass stunt (NGS) disease. This disease is caused by a phytoplasma, which is transmitted ... -
Non-target effects of the 'push-pull' habitat management strategy: Parasitoid activity and soil fauna abundance
Midega, Charles A.O.; Khan, Zeyaur R.; Ogol, Callistus K.P.O.; Bruce, Toby J.; Pickett, John A.; Van den Berg, Johnnie (ELSEVIER, 2009) -
Parasitoids Associated with mussidia spp. (Lepidoptera: Pyralidae) in Kenya
Muli, Benjamin Kimwele; Van den Berg, Johnnie; Schulthess, Fritz (SpringLink, 2009) -
Pest resistance to Cry1Ab Bt maize: field resistance, contributing factors and lessons from South Africa
Van den Berg, Johnnie; Hilbeck, Angelika; Bøhn, Thomas (ELSEVIER, 2013)This paper documents the historical development of resistance of the African maize stem borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae) to Bt maize (Zea mays L.). This pest was one of the first to evolve resistance ... -
Phylogeny and systematics of the Sesamia coniota Hampson species group (Lepidoptera: Noctuidae: Noctuinae: Apameini: Sesamiina), with the description of three new species from the Afrotropical region
Le Ru, Bruno; Van den Berg, Johnnie; Capdevielle-Dulac, Claire; Musyoka, Boaz K.; Sezonlin, Michel (Taylor & Francis, 2020)In this study, we review six morphologically similar species of Sesamia Guenée, 1852 from Africa, including three new species that are described: Sesamia corymbosus Le Ru n. sp., S. schoenoplectus Le Ru n. sp. and S. ... -
The rate of release of Cry1Ab protein from Bt maize leaves into water. Short communication
Du Pisanie, Amy; Du Preez, Louis; Van den Berg, Johnnie; Pieters, Rialet (WRC, 2019)Transgenic Bt maize plants are genetically modified to contain genes of Bacillus thuringiensis that encode for δ-endotoxins (Cry1Ab protein) that have insecticidal properties. These endotoxins target certain lepidopteran ...