Parthenium hysterophorus L. is a native plant of tropical and sub-tropical South and North America that adversely affects food security, biodiversity, and the health of both humans and livestock in East Africa. In East Africa, Parthenium reduces the yield of many major crops such as sorghum and corn, competes with preferred pasture species, and, when consumed by domestic animals, taints their milk and meat, thereby reducing their value. It also causes human health problems such as severe contact dermatitis and respiratory problems. In addition, because of its ability to release toxic chemicals, Parthenium can replace natural vegetation, thus adversely affecting plant biodiversity.
Zygogramma bicolorata, a leaf-eating beetle on Parthenium
In July, Zygogramma bicolorata, a leaf-eating beetle that feeds on Parthenium, was released at several sites around Wollenchiti, Ethiopia. The sites included a farmer`s field, a big uncultivated and a fenced area nearby a railway. The released Zygogramma, especially the second generation, has begun causing damage to Parthenium in cultivated as well as in non-cultivated areas. We are encouraged by the rapid establishment and spread of Zygogramma. Wollenchiti this year received heavy rain and that resulted in lush growth of Parthenium, which is ideal for the bioagent. Fencing the release plots also allowed Zygogramma to have adequate time to build its population before spreading to surrounding fields.
Zygogramma defoliated Parthenium in foreground. Near Wollenchiti, Ethiopia, September 7, 2016.
Zygogramma defoliated Parthenium (brownish plants beside fence)
This release was done through the “Biological control of the invasive weed Parthenium hysterophorus in East Africa” project led by Virginia State University, which has been awarded a grant of $748,465 by USAID through the Integrated Pest Management Innovation Lab managed by Virginia Tech. The goal of the project is to build on the accomplishments of the two previous USAID IPM IL-funded Parthenium projects to abate the spread and impact of the weed in east Africa. One of the objectives of the project is to scale-up the rearing and release of approved biocontrol agents, Zygogramma along with the stem boring Listronotus setosipennis in Ethiopia.
Wondi Mersie, Ph.D.
Associate Dean and Director of Research
Virginia State University
Petersburg, VA 23806