Ornamental Orange Tree Pests

Ornamental Orange Trees

• Edible oranges are called sweet oranges, and ornamental oranges are called sour oranges. The Citrus Experiment Station at the University of California Riverside maintains and researches over 1,000 kinds of citrus trees. Some ornamental sour orange trees in their collection include bergamot, Bouquet de Fleurs and chinotto. Oil of bergamot is pressed from bergamot orange rinds and gives Earl Grey tea its distinctive flavor. Bouquet de Fleurs bears sweetly scented flowers that are used to make perfume. Chinotto orange, or myrtle-leaf orange, is a dwarf ornamental that shows beautifully in patio pots because its small orange fruits are profuse and long-lasting on the tree.

Citrus Leafminer and Peelminer

• The citrus leafminer is appropriately named because its larvae mine tunnels through citrus fruit leaves. The adult leafminer is a moth that lays eggs on the undersides of leaves. When larvae hatch, they begin tunneling through tender new-growth foliage and leave telltale trails of frass, or excrement. When larvae are ready to pupate, they emerge from leaf tunnels and roll leaf edges around themselves. Peelminer is also a citrus moth, but its larvae feed on fruit instead of leaves.

Citrus Looper

• Citrus looper larvae are small worms that are the immature form of a moth. Adult female moths lay 100 eggs at a time, several times a year. Worms have legs at the fronts and backs of their bodies, but not in the middle. Their physical structure allows them a looping, or inching, mobility that gives them the common name of inchworm. Young looper larvae feed on tender leaf margins, and mature larvae consume entire leaves, flowers and fruit.

Citrus Psyllid

• Citrus psyllids are dangerous orange pests because they act as vectors, or agents that transmit disease. Candidatus Liberibacter asiaticus causes yellow shoot disease, which may be “the most devastating citrus disease in the world,” according to the Florida Department of Agriculture and Consumer Services. The disease causes yellow shoots and green fruit that do not attain proper color. Inspecting nearby orange jasmine plants is a good way to scout for citrus psyllids. Orange jasmine is a common host plant for this pest and may harbor extensive populations that migrate to ornamental orange trees.