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German wasp | Vespula germanica

German wasp

Vespula germanica

Coral bush | Ardisia crenata

Coral bush

Ardisia crenata

Purple loosestrife | Lythrum salicaria

Purple loosestrife

Lythrum salicaria

Pom pom weed | Campuloclinium macrocephalum

Pom pom weed

Campuloclinium macrocephalum

Canarybird bush | Crotalaria agatiflora

Canarybird bush

Crotalaria agatiflora

Peanut butter cassia | Senna didymobotrya

Peanut butter cassia

Senna didymobotrya

Rubber vine | Cryptostegia grandiflora

Rubber vine

Cryptostegia grandiflora

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Environmental Programmes

In order to tackle our country’s socio-economic challenges, the government adopted the Outcomes based approach to improve government performance and providing focus on service delivery. find out more

Differences in the emission of volatile organic chemicals in Lantana camara and implications for biological control efforts

Differences in the emission of volatile organic chemicals in Lantana camara and implications for biological control efforts
Heshula L.U.P.1, Wheeler G.S.2
1 Rhodes University, Grahamstown, South Africa; 2 USDA, Invasive Plant Research Laboratory, FL, USA

Leaf chemistry is a critical factor in the location, suitability and preference of plants by insects. Volatile organic chemicals (VOCs) play an important role in mediating plant insect interactions, and could provide valuable insight into agents’ behaviour in weed biological control. Mechanical damage studies provide a quick way to detect any VOC changes, and are a useful tool to simulate herbivory. Experiments to measure the quantitative and qualitative effects on VOCs emission were conducted by imposing mechanical damage to leaves of intact Lantana camara plants. Solid-phase microextraction (SPME) and Gas Chromatography-Mass Spectroscopy (GC-MS) were used to evaluate VOCs profile differences between the different treatments. Results showed a general increase in total VOCs emitted after damage on day 2, with cut leaf damage and punctured leaf damaged treatments increasing by 92% and 45% respectively, compared to undamaged leaves measured on day 1, demonstrating the phenotypic plasticity of this weed. On day 3 a decrease in the quantity of VOCs released was seen with a reduction of 66% and 65% in cut and punctured leaf treatments, respectively, indicating the need for continuous damage for the induced responses to be sustained. These results indicate that damage caused by cutting leaf material elicit stronger L. camara VOC responses than leaf piercing damage, results that potentially hold important insights into the weed- agent interactions of cutting and piercing leaf feeders of L. camara. These results may have important implications for biological control agents’ performance pre- and post-release evaluation.

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General News Updates

2019 National Symposium on Biological Invasio…

26-02-2019

This is your invitation to South Africa's 2019 National Symposium on Biological Invasions. The convention is hosted by the Centre for Invasion Biology (CIB), University of Stellenbosch, and the Biolo... Read more

2019 Invasive Species Training

22-01-2019

During the past five years (2014-2018), ISSA invasive species trainers have trained 4 000 in the identification of invasive species and laws pertaining to invasive species across South Africa.  ... Read more

Alien Grass Working Group

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Permits for planting indigenous Cynodon?

01-03-2018

On 16 February, 2018, South Africa's Department of Environmental Affairs issued amendments to the regulations and lists relating to the National List of Invasive Species.  Updates to the draft&n... Read more

Invasive species training 2018 dates released

28-02-2018

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Communications post for Africa advertised

25-01-2018

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