Orange trees can be heavily affected by insects (mainly aphids) and also by fungal, bacterial and virus diseases Aphids (mainly Aphis spiraecola) are small flies that are fed with the underside of leaves, often resulting in the curl of citrus leavesThis by itself is not a great damage, because the yield of a citrus tree is generally not greatly affected by the curling of leavesCitrus Tree Pests & Diseases Like all plants and trees, citrus trees can be affected by disease and insect damage There are some diseaseresistant citrus tree varieties, and they are the best option for preventing many issues Proper citrus tree maintenance such as watering, pruning, spraying, weeding, and removing fallen fruit can helpCalifornia farmers and scientists race to combat a citrus disease infecting trees The world's most insidious citrus disease invaded Florida in 05, wreaking havoc on its iconic groves with Orange Tree Bark Disease Gardening Forums Florida orange tree diseases pictures
