California Red Scale: Appearance, Territory, Damage, and Life Cycle

Latin Name: Aonidiella Aurantii Appearance: In California, citrus trees are attacked by two different types of scales, a tiny bug, which harms the plants’ fruit, foliage, and even the trees themselves. These are the yellow scale and the California red scale (Aonidiella aurantii) (Aonidiella citrina). Because the yellow scale can be readily managed by its natural predators, California red scale, also known as the citrus red scale, is currently a bigger problem. California red scale is an armored scale that attaches to citrus wood, fruit, and leaves. It spends most of its life behind a roundish waxy coating, with the exception of when it emerges or mates. Between 100 to 150 crawlers, which emerge from the female scales’ rounded cover and settle in tiny depressions on leaves, fruits, and twigs, are produced by each female scale. The cycle then restarts as they create their own waxy coverings. The roundish cover of a female scale is roughly the size of the blunt end of a nail. After four molts, the little, two-winged adult male scales emerge from the extended scale coverings. Hosts Plants: Aonidiella aurantii, often known as red scale or California red scale, is a pest that mostly affects citrus but can also affect fig, cotton, mango, banana, avocado, grape, and rose. It is a member of the Diaspididae family. Territory: Worldwide. Between 1868 and 1875, California was invaded by California red scale, which is thought to have arrived on citrus seedlings imported from Australia. The scale bug is a native of Southeast Asia, but it has spread to all dry and semiarid parts of the world where citrus is cultivated on citrus seedlings. Damage Insect Cause: The most serious pest that many nations that produce citrus have to deal with is Aonidiella aurantii. Because the saliva that they squirt during feeding is extremely poisonous to plant tissue, the populations can expand fast and do significant harm. The mouthpart of the California red scale enters the plant tissue and suctions the parenchymal cell contents. The presence of conspicuous yellow spots surrounding each gravid female on the leaves, which indicate a more severe infestation, may indicate the loss of shoots and branches. The fruit may have problems at any stage and possibly perish. Particularly in the case of immature citrus, the stem can sometimes be seriously affected and seem to be totally covered in shields. Life History and Habits: After harvest, California red scales spend the winter on twigs and leaves. Female adults lack legs and are immobile. 150 crawlers can be produced by a single female. The first stage of the scale which is mobile, known as a crawler, emerges from under the female scale and travels about one meter in search of a leaf, twig, or fruit to feed on. In order to become reproductive adults, female crawlers go through three nymphal instars. To develop into winged adults, males go through two nymphal instars, a pre-pupa stage, and a pupal stage. Male adults have a brief lifespan and pass away shortly after mating. Multiple generations can exist yearly since the life cycle can be finished in six weeks.