​Yellow bells (Tecoma stans)(Bignoniaceae)

Afrikaans: Geelklokkies; isiZulu: Insimbephuzi

The weed

Tecoma stans (Bignoniaceae) is an evergreen tree or shrub that is native to Mexico and southern USA. It was introduced to South Africa as an ornamental plant because of its beautiful yellow bell-shaped flowers and was first recorded in 1858. Yellow bells is well distributed in South Africa and currently occurs in seven provinces (Gauteng, Mpumalanga, Limpopo, KwaZulu-Natal, Eastern Cape, North West and rarely in Western Cape). It invades roadsides,  riparian areas, waste areas, disturbed sites and rocky sites in tropical and sub-tropical areas, and displaces the indigenous fauna and flora. It has been declared a category 1b species in terms of the Alien and Invasive Species Regulations (AIS), National Environmental Management: Biodiversity Act (Act No 10 of 2004), which state that it needs to be controlled wherever it is present, or to be removed and destroyed if possible. No trade or planting is allowed.​

Tecoma infestation.jpg Tecoma infestation
Tecoma seed pods.jpg 
Tecoma seed pod
Tecoma flower.jpg Tecoma flower


There are no registered herbicides for this plant in South Africa. Mechanical control is labour intensive and expensive because of the aggressive behaviour of Yellow bells. Since 2007, the Working for Water programme (initially of the Department of Water Affairs, now under the Department of Environmental Affairs), in collaboration with Agricultural Research Council, has been funding this project to investigate potential biological control agents from Mexico and Argentina. Three biological control agents have been developed successfully in South Africa, viz. a rust fungus, Prospodium transformans; a leaf feeding lady beetle, Mada polluta, and a leafmining fly, Pseudonapomyza sp.  The rust fungus was released in South Africa in 2010 but failed to establish in the field. Mada polluta was first released in October 2013, and has become established in Gauteng, Mpumalanga, Limpopo and KwaZulu-Natal Provinces. More releases will take place in all provinces where T. stans is distributed. The first releases of the leaf-mining fly, Pseudonapomyza sp., were made during November 2014, but it is still too early to confirm its establishment.

More information

The following ducments can be downloaded:

  • A review on this biocontrol project that was published during 2011pdf
  • A fact sheet on Tecoma stans pdf​
  • Raw data associated with  pre-release evaluation of Heikertingerella sp. as a potential biocontrol agent for Tecoma stans in South Africa pdf


Conta​​​​ct person: Lulama 'Lulu' Gracious Madire, E-mail: MadireL@arc.agric.za.

>>>Specific IAP Species and their control according to common names

>>>Specific IAP Species and their control according to botanical names