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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

What are the factors that influence successful biological control of Cereus jamacaru De Candolle (Cactaceae) in South Africa?

What are the factors that influence successful biological control of Cereus jamacaru De Candolle (Cactaceae) in South Africa?
Guy F. SUTTON, Iain D. Paterson
Biological Control Research Group, Department of Zoology and Entomology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa

The success of biological control agents can be highly variable among target weed populations. The mechanisms that determine such variability are poorly understood, and an understanding of these factors would allow biological control practitioners to improve existing management programs. Field observations of an environment-transforming weed, Cereus jamacaru (Queen of the night cactus), indicate that biological control efforts employing the mealybug Hypogeococcus pungens (Hemiptera: Pseudococcidae) may be more effective against certain weed populations than others, suggesting that distinct genetic types may be present in South Africa. This study will investigate several factors which may explain the variable nature of the control of C. jamacaru. The factors investigated will include the suitability of the control agent H. pungens, incompatibility between H. pungens and C. jamacaru populations and the impact of top-down regulation on H. pungens by predators and parasitoids. The methods employed will include field surveys of C. jamacaru populations and their interaction with H. pungens, climatic matching, molecular and morphological taxonomic evaluation of the weed populations, herbivore performance bioassays on different weed populations and combined field and laboratory-based assessments of the impact of predation and parasitism on H. pungens. This research will indicate whether H. pungens is a suitable biological control agent of all forms of C. jamacaru and determine factors that must be taken into account when implementing biological control using this agent. 

Read 2995 times Last modified on Tuesday, 03 May 2016 12:32

General News Updates

2019 National Symposium on Biological Invasio…


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


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


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?


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


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


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