Cassava mosaic disease is transmitted by an insect called Bemisia nigerensis. This insect, also known as the whitefly, feeds on the cassava plant and spreads the disease by carrying the virus from infected plants to healthy ones. The virus can also be spread through contaminated plant material or by using infected tools during planting. Once the virus infects a cassava plant, it causes yellowing and distortion of the leaves, stunted growth, and reduced yields. The disease can have devastating effects on cassava crops, which are a staple food source for millions of people in Africa.