The Pompom weed (Campuloclinium macrocephalum) is an ornamental South American herb belonging to the daisy family, Asteraceae. It is rapidly becoming the most serious threat to the conservation of grasslands in South Africa. Infestations become conspicuous when the plants are in flower between December and March, transforming the veld from green to pink. The plant initially establishes itself in disturbed sites such as roadsides, but then invades natural grasslands, open savanna and wetlands. This weed displaces native species, reducing both the biological diversity and carrying capacity of vleis and veld.
The plant initially establishes itself in disturbed sites such as roadsides, but then invades natural grasslands, open savanna and wetlands. This weed displaces native species, reducing both the biological diversity and carrying capacity of wetlands and veld. During winter the plant is not visible above-ground.
However, now there is good news! Bio-control scientists have released a tiny insect to wage war on the dreaded invasive Argentinian pompom weed and save our Highveld grasslands. Recently, bio-control scientists celebrated the release of a tiny insect known as the pompom thrips (Liothrips tractabilis) by releasing them into fields of pink-flowering pompom weed at Rietvlei Nature Reserve, south east of Pretoria.
Very difficult to remove (I tried pulling out a few of them and actually got nowhere - this weed breaks off just above the ground, leaving the large, tough roots underground.) Recruited from Argentina, where pompom weed is indigenous, the newly-released pompom Liothrips causes significant damage to the stems and leaf tissue at the growing tips. This causes deformities in plant growth, reducing the height, biomass and flower production of this unwanted weed. Scientists also warn that it will take several seasons for entomologists to build up large enough populations of Liothrips to halt the spread of pompom weed.
You can read more about this bio-control here.