Agricultural Research Council Plant Protection Research Institute

South Africa

Agricultural Research Council Plant Protection Research Institute

South Africa
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Mukwevho L.,Agricultural Research Council Plant Protection Research Institute | Mukwevho L.,University of KwaZulu - Natal | Olckers T.,University of KwaZulu - Natal | Simelane D.O.,Agricultural Research Council Plant Protection Research Institute
Biological Control | Year: 2017

The flower-galling mite, Aceria lantanae (Cook) (Acari: Trombidiformes: Eriophyidae), was released as a biological control agent of Lantana camara L. (Verbenaceae) in the Limpopo, Mpumalanga, Gauteng and KwaZulu-Natal provinces of South Africa, between 2007 and 2012. Flower galls were subsequently observed at several sites where the mite had not been released, providing evidence of dispersal. This study was therefore conducted to determine the establishment, seasonal performance and dispersal rate of A. lantanae in the aforementioned South African provinces and neighbouring Swaziland. The effect of A. lantanae along with the other previously-established biological control agents on inflorescence and seed production of susceptible L. camara varieties was determined by insecticide exclusion experiments in the field. Aceria lantanae became established at 58.6% of the original release sites located in the four provinces. The mite has also established widely within the geographic range of L. camara in South Africa and Swaziland, with dispersal rates of up to 40.6 km per annum. Infestations of inflorescences varied substantially between sites, provinces and seasons and ranged from 2.7% to 97%. Inflorescence and seed production declined significantly by up to 97% and 94%, respectively, on untreated biological control stands compared to the insecticide-treated exclusion stands. Although A. lantanae has become widespread within the geographic range of L. camara in South Africa, different L. camara plants appeared to vary in their susceptibility to A. lantanae, suggesting that genetic differences among plants may have affected the performance of the mite. If this is true, additional mite strains will be required to control resistant varieties. © 2017 Elsevier Inc.

Swanepoel P.A.,Stellenbosch University | Swanepoel P.A.,Outeniqua Research Farm | Du Preez C.C.,University of the Free State | Botha P.R.,Outeniqua Research Farm | And 2 more authors.
Soil Research | Year: 2015

Soil quality of pastures changes through time because of management practices. Excessive soil disturbance usually leads to the decline in soil quality, and this has resulted in concerns about kikuyu (Pennisetum clandestinum)-ryegrass (Lolium spp.) pasture systems in the southern Cape region of South Africa. This study aimed to understand the effects of tillage on soil quality. The soil management assessment framework (SMAF) and the locally developed soil quality index for pastures (SQIP) were used to assess five tillage systems and were evaluated at a scale inclusive of variation in topography, pedogenic characteristics and local anthropogenic influences. Along with assessment of overall soil quality, the quality of the physical, chemical and biological components of soil were considered individually. Soil physical quality was largely a function of inherent pedogenic characteristics but tillage affected physical quality adversely. Elevated levels of certain nutrients may be warning signs to soil chemical degradation; however, tillage practice did not affect soil chemical quality. Soil disturbance and the use of herbicides to establish annual pastures has lowered soil biological quality. The SQIP was a more suitable tool than SMAF for assessing soil quality of high-input, dairy-pasture systems. SQIP could facilitate adaptive management by land managers, environmentalists, extension officers and policy makers to assess soil quality and enhance understanding of processes affecting soil quality. © CSIRO 2015.

Bahramisharif A.,Stellenbosch University | Lamprecht S.C.,Agricultural Research Council Plant Protection Research Institute | Spies C.F.J.,Stellenbosch University | Spies C.F.J.,Agriculture and Agri Food Canada | And 2 more authors.
Mycologia | Year: 2013

The genus Pythium consists of more than 120 species and is subdivided into 11 phylogenetic clades (A-K) based on internal transcribed spacer (ITS) region sequence data. Pythium clade G contains only seven known species, with most not being well described. Our study characterized 12 Pythium isolates from Aspalathus linearis (rooibos) that fit into clade G. Phylogenetic analyses of the ITS region and a combined phylogeny of four gene regions (ITS, b-tubulin, COX1 and COX2 [cytochrome c oxidase subunits I, II]) identified five clade G subclades. The rooibos isolates formed two groups, Pythium Rooibos I (RB I) and II (RB II), that clustered into two separate clades within subclade 1. The nine Pythium RB I isolates formed a distinct clade from P. iwayamai and is described here as a new species, Pythium cederbergense sp. nov. The three Pythium RB II isolates had P. canariense and P. violae as their closest relatives and were genetically diverse, suggesting the presence of several new species or a species complex that cannot be resolved with the current data, thus precluding a species description of this group. Morphological analyses showed that P. cederbergense and Pythium RB II were indistinguishable from each other but distinct from known clade G species. Clade G studies are being hampered by imprecise morphological descriptions of P. violae, P. canariense and P. iwayamai and each species being represented by only one isolate. The P. cederbergense and Pythium RB II isolates all were nonpathogenic toward rooibos, lupin and oats seedlings. One oligonucleotide was developed for each of P. cederbergense and Pythium RB II, which was able to differentiate the isolates with DNA macro-array analyses. © 2013 by The Mycological Society of America.

Simelane D.O.,Agricultural Research Council Plant Protection Research Institute | Simelane D.O.,University of Cape Town
Biological Control | Year: 2010

A root-feeding flea beetle, Longitarsus bethae Savini & Escalona (Chrysomelidae: Altcinae), was introduced into South Africa to complement the impact of the above-ground insect agents already established on Lantana camara L. (Verbenaceae). To estimate the potential effectiveness of L. bethae for biological control of L. camara, growth of various plant components were measured under different levels of abundance of the insect under quarantine glasshouse and semi-field conditions. Populations of L. bethae larvae that developed in previously-sterilized soil from initial cohorts of 200 and 300 eggs per plant significantly stunted the growth of L. camara, causing reductions in the number of leaves, stem height, stem diameter, above-ground dry-mass, and below-ground dry-mass, of up to 54%, 21%, 31%, 34% and 40%, respectively. Compared with the controls, the larval population resulting from an inoculum of 100 eggs per plant usually had no statistically significant effect on plant growth. The degree of root damage caused by the larvae was directly proportional to the number of eggs added and to the number of adults that emerged. Under semi-field conditions, cumulative herbivory by L. bethae adults and larvae during a six-month period caused severe leaf and root damage, resulting in a cumulative decline of 148% in flower production. Overall, the ability of L. bethae to both directly suppress root growth and indirectly suppress leaf production, stem growth and flower production of L. camara, indicates that this flea beetle has the potential to make a considerable impact on the weed's invasiveness in South Africa. © 2010 Elsevier Inc.

Eardley C.,Agricultural Research Council Plant Protection Research Institute | Eardley C.,University of KwaZulu - Natal | Urban R.,Agricultural Research Council Plant Protection Research Institute
Zootaxa | Year: 2010

The purpose of this catalogue is to list the valid names, nomenclatorial history of, and published references to, the known bees of Sub-Saharan Africa and the western Indian Ocean islands, excluding the honey bee (Apis mellifera Linnaeus). An attempt has been made to include references to all publications on Afrotropical bees since Dalla Torre's (1896) catalogue, up to and including 2009. All publications dealing with each species are listed under the name combination used. This catalogue includes 2755 valid species and 1133 references. Taxonomic changes, such as new name combinations, with correct latinization and gender, are included. The distribution by country, plants visited, hosts (for parasitic bee species) and parasites are recorded, as are the type's gender, depository and country locality for each described species (valid and invalid). The following new combinations are included: Amegilla cincta conradsi (Strand), Evylaeus aeratus (Kirby), Evylaeus angustissimus (Cockerell), Evylaeus ankaratrense (Benoist), Evylaeus bellulus (Vachal), Evylaeus bianonis (Cockerell), Evylaeus burnupi (Cockerell), Evylaeus calviniellus (Cockerell), Evylaeus camphorellus (Cockerell), Evylaeus cardiurus (Cockerell), Evylaeus cephalinotus (Cockerell), Evylaeus cessulus (Cockerell), Evylaeus clavigerellus (Cockerell), Evylaeus coeruleodorsatus (Strand), Evylaeus coloratipes (Cockerell), Evylaeus constrictulus (Cockerell), Evylaeus cyaneodiscus (Cockerell), Evylaeus deceptus (Smith), Evylaeus diloloensis (Cockerell), Evylaeus diminutellus (Cockerell), Evylaeus discretulus (Cockerell), Evylaeus epichlorus (Cockerell), Evylaeus gastrophilinus (Cockerell), Evylaeus gendettensis (Cockerell), Evylaeus godmanae (Michener), Evylaeus hemicyaneum (Benoist), Evylaeus hirtulinus (Cockerell), Evylaeus kabetiellus (Cockerell), Evylaeus kampalensis (Cockerell), Evylaeus kasuloi(Cockerell), Evylaeus kowitensis (Cockerell), Evylaeus lactescens (Cockerell), Evylaeus lampronotus (Cameron), Evylaeus latibalteatus (Meade-Waldo), Evylaeus latior (Cockerell), Evylaeus leucophenax (Cockerell), Evylaeus morio (Fabricius), Evylaeus macilentus (Benoist), Evylaeus marshalli (Cockerell); Evylaeus matoporum (Cockerell), Evylaeus mediocre (Benoist), Evylaeus meruensis (Friese), Evylaeus meneliki (Friese), Evylaeus mesopolitus (Cockerell), Evylaeus microsellatus (Cockerell), Evylaeus mirifrons (Cockerell), Evylaeus natensis (Cockerell), Evylaeus nigritulinus (Cockerell), Evylaeus nitididorsatus. (Benoist), Evylaeus niveostictus (Cockerell), Evylaeus parvulinus (Cockerell), Evylaeus pastinimimus (Cockerell), Evylaeus percornutus (Cockerell), Evylaeus perihirtus (Cockerell), Evylaeus perileucus (Cockerell), Evylaeus pernitens (Cockerell), Evylaeus pilicornis (Friese), Evylaeus politescens (Cockerell), Evylaeus pulchripes (Cockerell), Evylaeus pulchritarsis (Cockerell), Evylaeus puzeyi (Cockerell), Evylaeus rubrocinctus (Cockerell), Evylaeus rufitarsellus (Cockerell), Evylaeus ruwenzicus (Cockerell), Evylaeus ruwenzoriellus (Cockerell), Evylaeus schubotzi (Strand), Evylaeus sellatiferus (Cockerell), Evylaeus semilucidus (Cockerell), Evylaeus sublautus (Cockerell), Evylaeus submetallicus (Benoist), Evylaeus tenuicornis (Cockerell), Evylaeus tenuivenis (Cockerell), Evylaeus thestis (Cameron), Evylaeus wilkinsoni (Cockerell), Evylaeus windhukensis (Friese), Heriades edentatus (Friese), Lasioglossum lukulense (Cockerell), Lasioglossum simulator (Cockerell), Lipotriches armatipes obscuripes (Friese), Lipotriches fumipennigera (Strand), and Megachile ambigua (Pasteels). One replacement name has been added: Hylaeus multifarius Eardley & Urban. © 2010 Magnolia Press.

Oldroyd B.P.,University of Sydney | Allsopp M.H.,Agricultural Research Council Plant Protection Research Institute | Lim J.,University of Sydney | Beekman M.,University of Sydney
Evolution | Year: 2011

The honey bee population of South Africa is divided into two subspecies: a northern population in which queenless workers reproduce arrhenotokously and a southern one in which workers reproduce thelytokously. A hybrid zone separates the two, but on at least three occasions the northern population has become infested by reproductive workers derived from the southern population. These parasitic workers lay in host colonies parthenogenetically, resulting in yet more parasites. The current infestation is 20-year old-surprising because an asexual lineage is expected to show a decline in vigor over time due to increasing homozygosity. The decline is expected to be acute in honey bees, where homozygosity at the sex locus is lethal. We surveyed colonies from the zone of infestation and genotyped putative parasites at two sets of linked microsatellite loci. We confirm that there is a single clonal lineage of parasites that shows minor variations arising from recombination events. The lineage shows high levels of heterozygosity, which may be maintained by selection against homozygotes, or by a reduction in recombination frequency within the lineage. We suggest that the clonal lineage can endure the costs of asexual reproduction because of the fitness benefits of its parasitic life history. © 2010 The Author(s). Evolution © 2010 The Society for the Study of Evolution.

Lamprecht S.C.,Agricultural Research Council Plant Protection Research Institute | Tewoldemedhin Y.T.,Agricultural Research Council Plant Protection Research Institute | Botha W.J.,Agricultural Research Council Plant Protection Research Institute | Calitz F.J.,Agricultural Research Council Biometry Unit
Plant Disease | Year: 2011

Thirty-three isolates of the Fusarium graminearum species complex obtained from diseased maize (Zea mays) crowns and roots in the Winterton district, KwaZulu-Natal province of South Africa were identified to species level. Their pathogenicity and virulence to maize 'PHI 32D96B' seedlings were determined under glasshouse conditions, with seedling survival and growth and crown and root rot as criteria. Phylogenetic analyses using the 3-O-acetyltransferase (Tri101) gene region sequences revealed the presence of F. boothii (2 isolates), F. graminearum sensu stricto (26 isolates), and F. meridionale (5 isolates) in the F. graminearum species complex associated with diseased maize crowns and roots. Pathogenicity results showed that F. boothii was the most and F. meridionale the least virulent of the three species. F. boothii and F. graminearum sensu stricto significantly reduced survival of seedlings and all three species caused significant reduction in growth and significantly more crown and root rot than the control (uninoculated). This is the first report of F. boothii, F. graminearum sensu stricto, and F. meridionale associated with diseased maize crowns and roots and their pathogenicity and virulence as soilborne pathogens on maize seedlings in South Africa. © 2011 The American Phytopathological Society.

Lyle R.,Agricultural Research Council Plant Protection Research Institute
African Invertebrates | Year: 2013

A new species of the tracheline genus Fuchibotulus Haddad & Lyle, 2008 (Araneae: Corinnidae) is described. Fuchibotulus haddadi sp. n. is only known from the type locality in the Eastern Cape Province, South Africa. An updated diagnostic key to all known species of the genus is provided.

Lyle R.,Agricultural Research Council Plant Protection Research Institute
African Invertebrates | Year: 2015

Two new species of trachelids of the Afrotropical genus Afroceto Lyle & Haddad, 2010 are described. Both species, A. ansieae sp. n. and A. dippenaarae sp. n., are endemic to South Africa. An updated identification key to males of the genus is provided. © FUNPEC-RP.

Madire L.G.,Agricultural Research Council Plant Protection Research Institute
Biocontrol Science and Technology | Year: 2013

The host range of Mada polluta Mulsant (Coleoptera:Coccinnellidae) was studied to assess its suitability as a biological control agent of Tecoma stans (L.) Juss ex Kunth var stans (Bignoniaceae), an invasive weed in South Africa. Biology of M. polluta and its host range were determined in the laboratory using no-choice and multi-choice feeding, oviposition and larval survival tests. Out of 36 plant species from 12 plant families (Bignoniaceae, Acanthaceae, Asteraceae, Verbenaceae, Lamiaceae, Oleaceae, Cucurbitaceae, Fabaceae, Scrophulariaceae, Solanaceae, Apiaceae, Chenopodiaceae and Poaceae) within the order Lamiales that were tested during the host specificity testing, M. polluta showed a very strong preference for T. stans, depositing its eggs on T. stans and none on non-target plant species. In no-choice tests, an average of 246 eggs was laid on T. stans, and from these, 133 larvae developed to adulthood. The beetle also showed very promising biological attributes that will contribute to its success as a biological control agent of T. stans. These attributes include highly damaging larvae and adults, high fecundity (532 eggs/female) and a short life cycle (four weeks). The short life cycle will enable multiple generations per year and rapid population increase in the field. It is concluded that M. polluta is sufficiently host-specific to be released against T. stans in South Africa. It is, therefore, strongly recommended that permission be granted to release this beetle from quarantine for biological control of T. stans in South Africa. © 2013 Copyright Taylor and Francis Group, LLC.

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