KENYA – A collaborative effort led by the Centre for Agriculture and Bioscience International (CABI) has unveiled a remarkable solution to the persistent menace faced by pawpaw farmers in Kenya and Africa.
Researchers have heralded the success of Acerophagus papayae, a small parasitic wasp imported from Ghana, in curbing the devastating impact of the invasive papaya mealybug (PMB), Paracoccus marginatus.
The invasive PMB, native to Mexico and Central America, wreaked havoc on Kenyan crops since its arrival in 2016, causing yield losses ranging from 57 to 91 percent, reports Farmers Review Africa.
With a voracious appetite, PMB attacks over 200 plant species, injecting toxic substances into leaves, stems, and fruits. Heavy infestations produce sticky honeydew and waxy secretions, rendering the affected fruits inedible and unsellable.
However, hope emerged as scientists from CABI, in collaboration with the Kenya Plant Health Inspectorate Service (KEPHIS), the Kenya Agricultural and Livestock Research Organization (KALRO), and Kenyatta University (KU), introduced A. papayae into the ecosystem.
The female parasitoids, by either host feeding or oviposition, played a pivotal role in reducing PMB populations.
Through a series of meticulously conducted experiments, the researchers discovered that A. papayae effectively parasitized PMB, demonstrating parasitism rates of 30% or higher at all research sites within a month.
The breakthrough doesn’t merely signal relief for pawpaw farmers. This environmentally friendly solution, integrated into an Integrated Pest Management (IPM) plan, also signifies a vital step toward reducing reliance on harmful chemical insecticides, safeguarding both agricultural yield and the environment.
Significant differences in host choice were noted when A. papayae was offered several host stages, with third instars being preferred over second instars. Adult females were preferred over third instars.
“The high parasitism rates and female-biased sex ratios obtained with third and adult female host instars indicate that mass rearing of A. papayae should be done with these host instar stages,” said Dr. Selpha Miller, lead author and Postdoctoral Research Fellow, Invasive Species Management at CABI
Farmers and agricultural experts alike are optimistic about the future, as the introduction of A. papayae offers a beacon of hope in the battle against invasive pests.
The success of A. papayae marks a significant milestone in the field of pest control. In harnessing the power of natural predators, scientists have struck a balance in nature, ensuring sustainable agriculture while preserving delicate ecosystems.