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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

Chemical ecology of cryptic species of Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae), biological control agents of water hyacinth (Eichhornia crassipes)

Chemical ecology of cryptic species of Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae), biological control agents of water hyacinth (Eichhornia crassipes)
Sandiso MNGUNI, Unathi L.P. Heshula, Iain D. Paterson, Julie A. Coetzee
Biological Control Research Group, Department of Zoology & Entomology, Rhodes University, Grahamstown

Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), is a floating aquatic macrophyte and is one of the world’s worst weeds. Its distribution extends in tropical, subtropical and warm temperate regions and it was first seen in South Africa around the 1900s, where it is currently most prominent in the coastal regions of KwaZulu Natal, and in the Vaal and Crocodile rivers of the North-West Province. The mirid, Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae), one of several biological control agents used against the weed, has two highly differentiated and distinct populations, one from Brazil and the other from Peru, that have recently been confirmed as reproductively isolated cryptic species. The aim of the project is to determine the pheromone production in these two reproductively-isolated cryptic species, and to determine whether pheromones have played a role in speciation. Odour-source experiments using Y-tubes and aeration chambers, as well as behavioural-observation experiments are in progress in the Chemical Ecology Laboratory, in the Department of Zoology and Entomology at Rhodes University (Grahamstown), to investigate the attraction of males towards females in both populations. Later, antennal preparations (antenna + ground electrode) will be connected to an Electroantennogram (EAG) to detect whether chemical compounds/olfactory stimuli have elicited an electrical response in the antenna of the mirids or not. Thereafter, chemical compounds will be analysed by Gas-Chromatography Mass-Spectometry (GC-MS) to identify specific compound(s) that stimulate the observed response. We predict that the quantity and quality of pheromones produced by these two reproductively isolated cryptic species will differ significantly.

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

04-09-2018

Who are we? The South African National Alien Grass Working Group was jointly initiated by the South African Biodiversity Institute (SANBI) and the Centre for Excellence in Invasion Biology (C·I·B) in... Read more

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

Interested in invasive species?  How much do you know about NEMBA invasive species compliance for landowners and organs of state? The South African Green Industries Council (SAGIC) have released... Read more

Communications post for Africa advertised

25-01-2018

The Nature Conservancy has advertised a brand new post:  Communications Manager, Africa Region. Knowledge of invasive species and water would be an asset in this post. See details below:    Job Titl... Read more