Ntungamo: The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), in collaboration with the Food and Agriculture Organization of the United Nations (FAO), the National Agricultural Research Organization (NARO) and the International Institute of Tropical Agriculture (IITA), working with the District Local Government, today released biological control agents (BCA) as a pest management strategy to control the mango mealybug (MMB) in Ntungamo District. The presence of the Mango mealybug (Rastrococcus invadens Williams), locally known as Kanyananga-Oruhumbo, was reported in November 2021 in Ntungamo District, Sofia cell, Kafunjo parish, Mirama Hill—the immediate border between Uganda and Rwanda. Since then, efforts have been geared towards the pest’s management.
In response, the Government of Uganda, through MAAIF, supported by FAO and IITA, released biological control agents (BCA), specifically two parasitoid wasps—Gyranusoidea tebygi and Anagyrus mangicola—to control the MMB in Ntungamo. FAO and the Government of Uganda have reviewed all the scientific data to ensure the introduction of these insects is safe and effective. The BCA methodology for pest management is the best approach to managing the mango mealybug because chemical pesticides have not been effective in controlling the pest. MAAIF, FAO and partners believe that the BCA will relieve the stress of farmers, who, fearing food insecurity and income loss, hired fumigators to spray their mangoes around July/August 2022. As much as the fumigants are highly toxic to the environment, MMBs are still present.
Speaking at the event to release the biological control agents, Hon. Fred Bwino Kyakulaga, Minister of State for Agriculture, noted that despite government efforts to transform the 38 percent of the population still stuck in the subsistence economy to the money economy while increasing production, productivity, value addition and agro industrialization, the agriculture sector is faced with many challenges, including diseases and crop pests such as mango mealybug.
“If not dealt with promptly, this pest can result in a 100 percent yield loss.”This pest has a waxy covering substance which protects the pest against any pesticide spray, making it extremely difficult to control, “he said. “It is therefore crucial that farmers report any new pest to any agricultural staff in their communities and that all the officers, leaders, and farmers play their roles to support the biological control of these pests. This will help us to manage the pest before it spreads deeper inland into other areas, “he added.
Protecting mangoes from mango mealybug damage can serve to protect the fruits that are important in the diets of the people in the community and also provide income that can be obtained from selling mango fruits. Processing of mango into juice is growing, but pests can hamper the growth in the processing industry in Uganda.
According to Antonio Querido, FAO Representative in Uganda, millions of dollars are spent to combat pests, money and investment that could have gone into other targeted agricultural investments, resulting in significant agricultural transformation and positive outcomes for farmers, agripreneurs, and actors along different agricultural value chains—Leaving No One Behind.
FAO has, for instance, in response to mango mealybug of concern here in Ntungamo and the country at large, spent about 200 000 US dollars (about UGX 760 million) in capacity development, mobilization, and raising of insects that can control mango mealybug in Uganda. In 2017 and 2018, FAO contributed 500 000 UGX (1.9 billion) to government efforts in building capacity for the management of Fall armyworm in Uganda. In 2020 and 2021, about 11 million (about UGX 41 billion) was mobilized for responding to desert locusts, including the procurement of vehicles, equipment, pesticides, awareness, and training and other innovations, he said.
Plant pests have always been a challenge for agriculture production. We have had to play catch up to develop the technologies to gain the upper hand in reducing their impact. In a globalized world, we have seen pests move further and faster than ever! Climate change is facilitating this, “he added.
However, Ntungamo District Local Government is optimistic that the introduction of the biological control agent will restore farmers’ hope and mango farming in the area.
“We thank the Ministry and FAO for the swift response to managing the mango mealy bug, which destroys leaves and fruits. This will ensure that the pest is contained and does not spread to other areas, “said Sam Mucunguzi, the District Chairperson of Ntungamo District. “Although farmers have registered losses this season, we believe that since a solution has been introduced, the next season will be better,” he added.
Mango mealy bug in East Africa
First reported in the East African Region, in Rwanda in 2019 and Burundi in 2020, the Mango mealybug (MMB) attacks over 100 plant hosts, and mangoes are the most preferred. The MMB has other alternative hosts, including citrus, guava, bananas, and pawpaws. In severely affected mango orchards, the pest can cause 89-100 percent yield loss and is extremely difficult to control by pesticide spray because it has a waxy covering substance that prevents the pesticide from penetrating and killing the pest.
Fungicides will not work because this is an insect pest and not a disease. MMB is known to develop resistance to many pesticides due to their rapid reproduction, and some of these pesticides are restricted by international trade partners, including the European Union.It is thus recommended that the safest and most effective control of the MMB is by biological control using parasitoid wasps. The wasps have been successfully utilized in MMB control in West Africa.
According to the Centre for Agriculture and Bioscience International (CABI), the mealybug feeds on the tree and produces droppings that make the leaves black and sticky. This lowers the strength of the tree and its production of mangoes. During a heavy attack, a whole part of the tree looks blackish in color. This insect pest lowers the yield and quality of the mango and can be passed from one tree to another by wind, water, contaminated farm equipment, and people. MMB colonies appear as white masses under the leaves of the mango and can be mistaken for funguses. The white mass is just thousands of mealybugs feeding on the leaves, sucking their juices.
Uganda has witnessed crop devastation and loss of income for its people owing to migratory and occasional pests affecting various crops. For instance, Fall Armyworm was first experienced in Uganda in 2016 and has now spread over the country, affecting maize and sorghum production. The recent desert locust invasion in 2020 in some countries in Africa (including parts of Uganda)—the worst in decades—greatly affected crops and food production.