Note the notch on the left margin of the leaf, which is symptomatic for this disease. 5. Citrus Insects & Diseases. Citrus canker is a highly contagious bacterial infection of citrus trees causing yellow halo-like lesions or scabs on the fruit, leaves and twigs of citrus trees. Another excellent resource for any citrus … SOOTY MOULD Sooty mould is common on citrus. Citrus pests and their natural enemies, Integrated Pest Management in Australia, QLD Department of Primary Industries, ISBN 0 7242 6695 X; Citrus Diseases and Disorders (2004) by Patricia Barkley formerly from New South Wales Industry & Investment (NSW I&I). It's a black fungus that grows and feeds on the sugary wastes (honeydew) excreted by sucking insects such as whiteflies, scale insects … Citrus snow scale (Unaspis citri) is an armored scale that is a sporadic pest and host specific on citrus trees.Heavy infestations can almost completely cover the bark and larger limbs and give a white, snowy appearance. Exotic Citrus Diseases: Early Detection is the Solution to Protecting Florida Citrus Exotic Diseases of Citrus 2020–2021 Florida Citrus Production Guide: Exocortis, Cachexia, and Other Viroids Citrus-producing regions in the United States are at high risk for the introduction and establishment of invasive pests and diseases due to their close proximity to international ports of entry and warm climatic conditions. Here is a list of the most common aliments of the citrus tree. Citrus tree pests and diseases Citrus trees are one of the most productive and easy to grow trees in the home garden but just us we love to reap its awards so do pests and diseases. The first symptom of citrus chlorotic dwarf on a leaf of a rough lemon seedling after inoculation. Citrus Diseases Citrus Canker. Severe infections can cause leaf loss, blemished fruit, fruit drop and die back.