White Flies; A Dangerous pest which has Hit Cassava in Uganda

By Mulopi Joseph,CE LAC Mayuge Farmers network. Edited by Maria

white flies on cassava

White flies cause direct damage to plants by sucking plant sap and removing plant nutrients, thereby weakening the plants. Damage may be more severe when plants are under water stress. In addition, they often produce large quantity of honeydew that leads to the growth of sooty mold on the lower leaves, blocking or reducing the photosynthetic capacity of the plants. The honey dew also contaminates the marketable part of the plant, reducing its market value or making it out put unsaleable. Infested plants may wilt; turn yellow in color, and black, become stunted or die in young plants when white fly infestations are severe or of long duration.

White flies are also serious indirect pests as vectors of virus diseases and they transmit virus diseases on cassava, cotton, tobacco, tomato, beans, chilies, and sweet potatoes. This white fly is the vector of a range of leaf curl disease-inducing the Tomato Yellow Leaf Curl Virus, the Cassava Mosaic Virus, the Cow pea Mild Mottle Virus, and the Watermelon Chlorotic Stunt Virus among others.

Several species of white flies are found on cassava plants; Feeding on the sap of the plant causes direct damage, which may cause considerable reduction in root yield if prolonged attack occurs.

The adults and nymphs of this white fly occur in large numbers on the lower surfaces of leaves covered with large amount of white waxy material. Females lay eggs on the lower leaf surface in spiral patterns (like fingerprints) of white material secreted by the female. This white fly sucks sap from cassava leaves. It excretes large amounts of honeydew, which supports the growth of black sooty mold on the plant, causing premature fall of older leaves.

Note; the black leaves.