Initiation of Biological Control AgainstParthenium hysterophorusL. (Asteraceae) in South Africa

"Survival and dispersal of the stem-boring weevil, Listronotus setosipennis, and the leaf-feeding beetle, Zygogramma bicolorata, one year after their release for the control of the invasive weed, Parthenium hysterophorus, at two locations in Ethiopia"

“…Listronotus setosipennis was field released in Australia in 1982 (Wild et al, 1992) and in South Africa in 2013 (Strathie et al, 2016). In Australia it readily established at several sites and appears to be well suited for areas with prolonged dry periods and erratic rainfall (Strathie et al, 2011). Similarly, it is quickly establishing in South Africa (50%+ of sites) (L. Strathie pers.…”

“…In its native range, parthenium is kept under control by natural enemies. Several countries including Australia, India, and South Africa (Dhileepan and McFadyen, 2012;McConnachie, 2015;Strathie et al, 2011) have introduced natural enemies to control parthenium. One of these natural enemies used against parthenium is Zygogramma bicolorata (Coleoptera: Chrysomelidae).…”

Implications of elevated carbon dioxide on the susceptibility of the globally invasive weed, Parthenium hysterophorus, to glyphosate herbicide

“…Native to the neo‐tropics, P. hysterophorus is a globally significant noxious annual herb, prevalent in more than 40 countries as a troublesome invasive . In South Africa, P. hysterophorus is widely recognised as one of the country's most threatening invasive plants, encompassing an array of negative ecological and socio‐economic impacts . The weed readily invades a wide variety of habitats, but is most problematic in agricultural settings, including croplands, grazing pastures, rangelands and fields left fallow .…”

“…The weed readily invades a wide variety of habitats, but is most problematic in agricultural settings, including croplands, grazing pastures, rangelands and fields left fallow . Typically germinating with the onset of spring rains, P. hysterophorus flowers rapidly (~6 weeks), producing 15 000–150 000 seeds per plant, prior to its annual die‐back in late autumn . Rapid development and prolific seed production are key to P. hysterophorus ' s invasive potential, allowing the formation of dense monospecific stands, which aggressively outcompete and exclude surrounding vegetation .…”

“…Rapid development and prolific seed production are key to P. hysterophorus ' s invasive potential, allowing the formation of dense monospecific stands, which aggressively outcompete and exclude surrounding vegetation . Prolific seed production often results in the formation of extensive and long‐lasting seedbanks, which can exceed 100 000 seeds/m 2 and remain viable for more than 5 years, making management challenging and costly . Although biological control is viewed as the long‐term solution in South Africa, many agricultural and commercially valued areas remain focused and reliant upon herbicidal controls to effectively manage P. hysterophorus invasions nationally and internationally.…”