scholarly journals Puccinia abrupta var. partheniicola on Parthenium hysterophorus in Southern Africa

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 327-327 ◽  
Author(s):  
A. R. Wood ◽  
M. Scholler
Keyword(s):  
South Africa ◽  
Biological Control ◽  
High Altitude ◽  
Southern Africa ◽  
Plant Protection ◽  
Rust Fungus ◽  
Parthenium Hysterophorus ◽  
International Institute ◽  
Native Range ◽  
Research Institute

Parthenium weed (Parthenium hysterophorus L., family Asteraceae), an annual herb of neotropic origin, is an invasive noxious weed with a pantropical distribution (1). It is particularly undesirable because of the serious health risks it poses to people living close to infestations (1). In January 1995, S. Neser (ARC-Plant Protection Research Institute, Pretoria, South Africa) collected a rust fungus on this plant near Brits, Northwest Province, South Africa (25°35′S, 27°46′E). Only uredinia were present. The same rust fungus was collected in the same area in January, March, and June of 2001, and again only uredinia were observed. In its native range, P. hysterophorus is infected by two rust fungus species, Puccinia abrupta Diet. & Holw. var. partheniicola (Jackson) Parmelee and Puccinia melampodii Diet. & Holw., but the latter species is microcyclic with telia only. The morphology of the urediniospores in the South African collections corresponds to Puccinia abrupta var. partheniicola (3): obovoid to almost triangular, 22 to 27 × 18 to 25 µm, echinulate, two subequatorial and one apical germ pores, spines absent around germ pores, wall 1 to 2.5 µm thick. The native range of Puccinia abrupta var. partheniicola is Mexico and northern South America (3). In addition, it has been recorded from Mauritius (3), Kenya, and India (H. C. Evans and C. A. Ellison, International Institute of Biological Control, CAB, 1987, unpublished data). It was intentionally introduced into Australia for the biological control of P. hysterophorus (2). Thirteen specimens in the Arthur Herbarium were examined, and only two had telia in addition to uredinia. The other 11 had only uredinia, indicating that nonformation of telia is common. Telia and uredinia are produced in high altitude, semiarid areas of Mexico, whereas in low altitude, more humid areas only uredinia are produced (1). The production of telia appears to depend on environmental conditions, and their absence is not unexpected at the Brits site, which is a high altitude (1,120 m) area with high summer rainfall (400 to 600 mm per year from November to February) and dry winters. Voucher specimens were deposited at the National Collection of Fungi, Plant Protection Research Institute, Pretoria (PREM 57298) and the Arthur Herbarium, West Lafayette, IN (PUR N1117). To our knowledge, this is the second report of this rust fungus in Africa and the first in southern Africa. References: (1) H. C. Evans. Trans. Br. Mycol. Soc. 88:105, 1987. (2) A. Parker et. al. Plant Pathol. 43:1, 1994. (3) J. A. Parmelee. Can. J. Bot. 45:2267, 1967.

Puccinia gladioli.

2021 ◽  
Author(s):  
Keyword(s):  
South Africa ◽  
North Africa ◽  
Rust Fungus ◽  
Life Stages ◽  
Sexual Stage ◽  
Native Range ◽  
The West ◽  
The Usa ◽  
Asexual Form ◽  
Accidental Introduction

Abstract P. gladioli is a heteroecious rust fungus, an obligate parasite with alternating life stages on different plants. The asexual form occurs on species of Valerianella, producing aeciospores that then infect Gladiolus species. The production of teliospores, the sexual stage, on Gladiolus, completes the cycle. Both stages are known in Europe, North Africa and southwestern Asia, but only the aecial form has been reported in North America, and only on the west coast. The fungus is a Regulated Pest for the USA (Wise et al., 2004) and is absent from South Africa and Australia, where other Gladiolus species are native or naturalized. Although not a significant problem in its native range, this rust fungus could be damaging as an invasive in other temperate areas. Small amounts of infection may be overlooked; therefore accidental introduction of the rust could occur through importation of infected germplasm by the horticultural industry or flower enthusiasts.

General discussion

1988 ◽  
Vol 318 (1189) ◽  
pp. 375-376
Keyword(s):  
Biological Control ◽  
The Netherlands ◽  
Multidisciplinary Approach ◽  
Plant Protection ◽  
Resistance Breeding ◽  
The Other ◽  
Control Methods ◽  
Plant Virology ◽  
And Control ◽  
Research Institute

A. K. Minks ( Research Institute for Plant Protection, Wageningen, The Netherlands ). The organizers should be given much credit for arranging this meeting on biological control where attention has been given not only to entomological but also to the other disciplines of plant protection. It is my belief that a multidisciplinary approach is the only way to develop biological control methods and to implement them successfully. In our Institute we became aware of this and recently we decided to leave the classical organizational division in entomology, mycology, plant virology, etc. sections and to change to sections named: detection, ecology, genetics and resistance breeding, and control, in which entomologists, mycologists, etc. have a much better possibility to work together.

A Decade of Biological Control of Parthenium hysterophorus L. (Asteraceae) in South Africa Reviewed: Introduction of Insect Agents and Their Status

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
L.W. Strathie ◽  
B.W. Cowie ◽  
A.J. McConnachie ◽  
F. Chidawanyika ◽  
J.N. Musedeli ◽  
...  
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Parthenium Hysterophorus

Prioritising biological control agents for release against Sporobolus pyramidalis and Sporobolus natalensis (Poaceae) in Australia

2021 ◽  
Author(s):  
◽  
Guy Frederick Sutton
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Host Range ◽  
Natural Enemies ◽  
Sub Saharan Africa ◽  
Native Range ◽  
Biological Control Agents ◽  
Potential Control ◽  
Eastern Australia ◽  
Close Phylogenetic Relationship

Sporobolus pyramidalis Beauv. and S. natalensis (Steud.) Th. Dur. and Schinz. (giant rat’s tail grass) (Poaceae), invade rangelands and pastures in eastern Australia, costing the livestock industry approximately AUS$ 60 million per annum in grazing losses. Mechanical and chemical control options are costly and largely ineffective. Biological control is viewed as the most promising control option, however this management strategy has largely been avoided for grasses, due to their perceived lack of suitably host-specific and damaging natural enemies. In this thesis, the prospects for using biological control against S. pyramidalis and S. natalensis in Australia was assessed, in light of these potential challenges. Climate matching models were used to identify high-priority geographic regions within the plants’ native distributions to survey for potential biological control agents. High-priority regions to perform surveys were identified by modelling the climatic suitability for S. pyramidalis and S. natalensis in sub-Saharan Africa (i.e. their potential native ranges’), and climatic compatibility with regions where biological control is intended in Australia. High-priority regions for S. pyramidalis included: (1) coastal East Africa, ranging from north-eastern South Africa to Uganda, including south-eastern DRC, (2) some parts of West Africa, including inland regions of the Ivory Coast and western Nigeria, (3) northern Angola and (4) eastern Madagascar, and for S. natalensis included: (1) eastern South Africa, (2) eastern Zimbabwe, (3) Burundi, (4) central Ethiopia and (5) central Madagascar. Prospective control agents collected from these regions have the highest probability of establishing and proliferating in Australia, if released. In surveys of the insect assemblages on S. pyramidalis and S. natalensis in the climatically-matched region of eastern South Africa fifteen insect herbivores associated with the grasses were identified. Insect feeding guild, geographic distributions, and seasonal abundances suggest that three stem-boring phytophagous wasps, Tetramesa sp. 1, Tetramesa sp. 2 and Bruchophagus sp. 1 (Hymenoptera: Eurytomidae), have potential as control agents. Species accumulation curves indicated that additional surveys in South Africa are unlikely to yield additional potential control agents. Field host-range surveys of 47 non-target grass species in South Africa showed that Tetramesa sp. 1, Tetramesa sp. 2, and Bruchophagus sp. 1, were only recorded from S. pyramidalis and S. natalensis. Integrating field host-range with phylogenetic relationships between plant species indicated that no native Australian Sporobolus species or economic crops and pastures are expected to be attacked by these wasps. All three wasp species are predicted to be suitably host-specific for release in Australia. Three other endophagous herbivores attacked non-target native African Sporobolus species that share a close phylogenetic relationship to native Australian Sporobolus species, and therefore, demonstrate considerable risk of non-target damage. These species should not be considered as potential control agents. Under native-range, open-field conditions, Tetramesa sp. 1 caused an approximately 5-fold greater reduction in plant survival and reproductive output than Tetramesa sp. 2 and Bruchophagus sp. 1. Tetramesa sp. 1 in combination with Tetramesa sp. 2 did not significantly increase the level of damage, while Bruchophagus sp. 1 may decrease the efficiency of Tetramesa sp. 1, if released in combination. Tetramesa 1 is therefore the most promising candidate agent. Prioritising potential agents using predicted efficacy allowed otherwise equally suitable prospective agents to be prioritised in a strategic manner. Prioritising which natural enemies to target as biological control agents is a complex task. Field host range and damage assessments in the native range may provide more realistic data than typical studies performed under artificial conditions in a laboratory or quarantine. Moreover, it could assist practitioners in prioritising the most suitable agent(s) at the earliest stage in the programme as possible. This study demonstrated that grasses are suitable targets for biological control as they can harbour host-specific and damaging natural enemies.

Region of Birth and Child Mortality among Black Migrants to South Africa: Is there a foreign-born advantage?

2016 ◽  
Vol 13 (3) ◽  
pp. 359-376 ◽  
Author(s):  
Tiffany L Green ◽  
Amos C Peters
Keyword(s):  
South Africa ◽  
South African ◽  
Child Mortality ◽  
Southern Africa ◽  
Strong Relationship ◽  
Developed Countries ◽  
Black Immigrants ◽  
Foreign Born ◽  
Region Of Origin ◽  
Child Deaths

Much of the existing evidence for the healthy immigrant advantage comes from developed countries. We investigate whether an immigrant health advantage exists in South Africa, an important emerging economy.  Using the 2001 South African Census, this study examines differences in child mortality between native-born South African and immigrant blacks.  We find that accounting for region of origin is critical: immigrants from southern Africa are more likely to experience higher lifetime child mortality compared to the native-born population.  Further, immigrants from outside of southern Africa are less likely than both groups to experience child deaths.  Finally, in contrast to patterns observed in developed countries, we detect a strong relationship between schooling and child mortality among black immigrants.

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