Insect herbivores associated with the invasive herb Senecio madagascariensis (Asteraceae) in its native range in KwaZulu-Natal, South Africa and their potential as biological control agents in invaded countries

2019 ◽  
Vol 30 (3) ◽  
pp. 243-255 ◽  
Author(s):  
Daniella Egli ◽  
Terence Olckers
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Insect Herbivores ◽  
Native Range ◽  
Biological Control Agents ◽  
Kwazulu Natal

Seasonal abundance and parasitism of Mesoclanis seed flies (Diptera: Tephritidae) in South Africa, and implications for the biological control of Chrysanthemoides monilifera (Asteraceae) in Australia

1998 ◽  
Vol 88 (4) ◽  
pp. 407-414 ◽  
Author(s):  
P.B. Edwards
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Nature Reserve ◽  
Seasonal Abundance ◽  
Western Cape ◽  
Flowering Period ◽  
Eastern Cape ◽  
Biological Control Agents ◽  
Kwazulu Natal

AbstractThe seasonal abundance and rates of parasitism of three species of Mesoclanis seed flies was studied in South Africa. The three species occur on Chrysanthemoides monilifera, and were recorded during most months of the year, whenever C. monilifera was flowering. At three sites in KwaZulu-Natal, numbers of eggs per capitulum of Mesoclanis polana Munro were highest on C. monilifera rotundata between June and November (winter/spring), towards the end of the main flowering flush. Parasitism of M. polana was between 50% and 90% for most of the year. Two other species of Mesoclanis (M. magnipalpis Bezzi and M. dubia Walker) occurred together on C. m. rotundata in the Eastern Cape (St Francis Bay), where parasitism during the year was between 55% and 95%. Peak numbers of eggs per capitulum (M. magnipalpis and M. dubia combined) occurred in May/June (winter), in the latter part of the main flowering flush. Mesoclanis magnipalpis was the only species recorded on C. m. pisifera in De Hoop Nature Reserve (Western Cape), where there was only one peak of oviposition (May/June), coinciding with the short and discrete flowering period of this subspecies. Parasitism was between 50% and 65%. At least nine species of parasitoid were reared from immature Mesoclanis stages. Eurytoma sp. (Eurytomidae) was a dominant parasitoid at all sites. Results are discussed in relation to the possible effectiveness of species of Mesoclanis seed flies as biological control agents of C. monilifera in Australia.

scholarly journals Insect Herbivores Associated with Nymphaea mexicana (Nymphaeaceae) in Southern United States: Potential Biological Control Agents for South Africa

2020 ◽  
Vol 103 (1) ◽  
pp. 54
Author(s):  
Megan K. Reid ◽  
Julie A. Coetzee ◽  
Martin P. Hill ◽  
Rodrigo Diaz ◽  
Lyn A. Gettys ◽  
...  
Keyword(s):  
United States ◽  
South Africa ◽  
Biological Control ◽  
Southern United States ◽  
Insect Herbivores ◽  
Biological Control Agents

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.

scholarly journals First Screening of Entomopathogenic Nematodes and Fungus as Biocontrol Agents against an Emerging Pest of Sugarcane, Cacosceles newmannii (Coleoptera: Cerambycidae)

Insects ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 117 ◽  
Author(s):  
Marion Javal ◽  
John S. Terblanche ◽  
Desmond E. Conlong ◽  
Antoinette P. Malan
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Chemical Control ◽  
Entomopathogenic Nematodes ◽  
Biocontrol Agents ◽  
Sugar Production ◽  
Biological Control Agents ◽  
Sugarcane Stalk ◽  
Reduce Sugar ◽  
Steinernema Yirgalemense

Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus were investigated as potential biological control agents to be used in an integrated pest management system. The nematodes Steinernema yirgalemense, S. jeffreyense, Heterorhabditis indica, and different concentrations of the fungus Metarhizium pinghaense were screened for efficacy (i.e., mortality rate) against larvae of C. newmannii. The different biocontrol agents used, revealed a low level of pathogenicity to C. newmannii larvae, when compared to control treatments.

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.

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