On October 24-28, 2022, The Rwanda Agriculture and Animal Resources Development Board, in partnership with the Food and Agriculture Organization-Rwanda Chapter, conducted a countrywide five-day campaign against Mango Mealybugs and its related mango diseases including Fruit Fly and Powdery Mildew control.

During the campaign, farmers were educated about mango mealybugs, powdery mildew and fruit fly control practices, including pruning, pesticide spraying and hoeing the soil under the tree canopy.

The main objective of the campaign is to raise mango producers’ awareness about the infestation status across the country and the biological control approach, among other topics.   

The mealybugs control campaign took place in Bugesera, Kirehe, Ngoma, Kayonza, Gatsibo and Nyagatare District in the Eastern Province; Kamonyi, Ruhango, Nyanza and Huye in the South; Karongi, Nyamasheke, Rusizi in the West of Rwanda, and the City of Kigali.

Mango Mealybugs

Mango mealybug is insect pests of mango. The mealybug feeds on the tree, and produces droppings which make the leaves black and sticky. This lowers the strength of the tree, and its production of mangoes. During heavy attack, a whole part of the tree looks blackish in colour.

This insect pest lowers the yield and quality of the mango and can go from one tree to another, if the trees are touching. Young mealybugs are brown in colour. Females are about half the size of your small nail, do not have wings and are covered with white wax. Male adults are brick red, winged and smaller than the wingless female.

Prevention

• Prune tress to remove highly infested damaged branches.
• Remove fallen old leaves from previous season. However, if only few insect pests and no major diseases are in your crop, then leave leaves as they improve the soil, and reduce water evaporation.
• Remove weeds from field borders during cropping periods to avoid alternative host to the bugs.
• Spray the whole plant, not only where mealybugs are visible.

Monitoring

• Check stem joints, under leaves and other protected areas of the plant for cotton wool like small ball insects.
• Mealybug insects are about 2-3mm and have a white waxy body.
• Sticky leaves indicate mealybugs due to the secretions they produce to attach themselves to the plants.
• Look for wilting, yellowing or deformed leaves on infected plants.
• Consider action when finding 5 to 20 colonies of mealybugs per small tree.
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Direct Control

• Brush off or crush mealybugs on small scale farms.
• Blast bugs off with a strong stream of water, often effective in the early stages of infestation.
• At larger infestations, spray with a mixture of dishwashing liquid and water. Use equal parts of each and stir to mix rather than shaking to avoid excess foam.
• Buy and release mealybug predator Cryptolaemus montrouzieri, known as “mealybug destroyer”