Survey and clearing of Cylindropuntia fulgida var. mamillata (boxing glove cactus) and Cylindropuntia pallida (thistle cholla)

Survey and clearing of Cylindropuntia fulgida var. mamillata (boxing glove cactus) and Cylindropuntia pallida (thistle cholla)
Travor Xivuri
Invasive Species Programme, South African National Biodiversity Institute, Private Bag X7, Claremont, 7735. 

Cylindropuntia fulgida var. mamillata forma monstrosa (boxing glove cactus) and Cylindropuntia pallida (thistle cholla) are native to south-western USA and northern Mexico. Invasive populations of these cacti have been found in the arid areas of the Northern, Western and Eastern Cape provinces of South Africa, with the invasions likely the result of escapes from succulent gardens. Since 2011,

738 532 ha of farmland have been surveyed to search for boxing glove cactus by visiting farms and homesteads and interviewing landowners. Populations of boxing glove cactus have been chemically controlled  using  4%  Garlon  (Triclopyr  (as  butoxy  ethyl  ester)  480  g/L)  at  thirteen  sites  in  the Northern and Eastern Cape (total of 217 ha). Cochineal insects (Dactylopius tomentosa) were released at a further four sites in the Northern Cape and are currently being monitored. Cylindropuntia pallida has been chemically controlled at four sites (384 ha) in the Eastern Cape using 2% Garlon. There is no effective biological control agent available in South Africa for C. pallida. I will be  giving  feedback  on  the  progress  to  date  of  managing  these  two  species,  including  the effectiveness of our surveillance strategies and control methods, and how our new insights into these species’ distributions and dispersal vectors will help us improve future management plans.