Hakea sericea is a member of the Proteaceae family and has long, needle-shaped leaves, which gives rise to the common name for most hakeas, needle bush. Like many Proteaceae, H. sericea is a serotinous species, which releases its seeds post-fire. This adaptation leads to some trees expelling in excess of 10 000 seeds when exposed to fire events. Germination post-fire is quite rapid and the species is a good competitor, adding to its invasive potential in Fynbos regions where it is a major threat to biodiversity. 

 

The mature fruits of H. sericea consist of two woody dehiscent halves which open only once the plant dies or in response to fire, releasing two black, winged seeds. The plants only develop fruits in their second or third year of life. Silky hakea flowers during the late autumn and early spring months, and produces silky wisp-like flowers which occur in curls, close to the tips of the spiky leaves. 

Historically, H. sericea has been controlled by both slash-and-burn techniques, and by extensive clearing operations through the Working for Water Programme within the South African Department of Environmental Affairs. These techniques had varying levels of success, but ultimately proved too costly, given the extent of the hakea infestation. Biological control of H. sericea was initiated in the 1960s, following the first introductions of seed-feeding insects, the weevil, Erytenna consputa and the seed-feeding moth, Carposina autologa. An additional weevil species, Cydmaea binotata, was unsuccessful as a biocontrol agent and efforts at establishing the species were abandoned shortly after its original introduction.  Several other species are used in combination, in an effort to control the spread of hakea. The indigenous fungus, Colletotrichum acutatum, was noted as having an impact on hakea mortality at several sites, in 1969, and has since been developed further into a mycoherbicide. In the later years of biocontrol on H. sericea, two new agents were introduced from Australia. The stem-boring beetle Aphanasium australe was introduced in 2001 and the flower-bud feeding weevil, Dicomada rufa, was introduced in 2005. Investigations into the efficacy of each of these established agents are ongoing, but it is hoped that an integrated approach, adopting agents that impact on varying stages of the weed, will have the greatest impact in reducing the overall spread of H. sericea.