Fiorinia theae | |
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Fiorinia theae 2nd instar female - a) antenna; b) anterior spiracle c) large gland spine; d) small microduct; e) enlargement of pygidium. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hemiptera |
Suborder: | Sternorrhyncha |
Family: | Diaspididae |
Genus: | Fiorinia |
Species: | F. theae |
Binomial name | |
Fiorinia theae Green, 1900 [1] | |
Fiorinia theae, the tea scale, is a polyphagous scale insect which is native to Asia and has been introduced into the Americas. It is widely distributed on both continents, especially in warmer regions. Apart from tea ( Camellia sinensis ), the host plants include a range of trees and shrubs, both ornamentals and crops. For example, other Camellia species, Citrus or Ilex (holly) species are part of the host range. Infested plants turn yellow and might die after heavy infestation. [2] [3] [4]
Fiorinia theae was originally described from tea plants in India and has been recorded also from various other countries in southern Asia, ranging from Sri Lanka in the west to the Philippines, Taiwan and southern China in the east. [2]
It was introduced into the U.S. in the beginning of the 20th century and in 1908 was already recorded as a pest of ornamental camellias in South Carolina. [4] It is now widely distributed in the Americas and has been recorded in most eastern and south-central states of the U.S., up to Texas and Kansas in the west and Indiana, Pennsylvania and Massachusetts in the north. There are also reports from California. It is further found in Central America and in Argentina in South America. [2]
The first instar larvae (crawlers) of Fiorinia theae are yellowish. The 2nd instar female is elongated with a dark brown scale cover, between 1.0 and 1.5 mm long. Immature males are smaller, less elongated and have a white scale cover. During heavy infestations, white wax secretions become abundant, giving the infected leaf a whitish appearance. Like in other scale insects, adult males are wasp-like with 1 pair of wings, one pair of halteres, and non-functional mouthparts. [2] [5] [4]
Fiorinia theae is a polyphagous scale insect of woody plants, infesting the underside of the leaves. Apart from tea plants in Asia, ornamental Camellia and Ilex species are the main hosts. Many other plants are infested less regularly. [5] ScaleNet lists more than 20 genera from 18 plant families as hosts, including various crops and ornamental trees. [2]
The development time and number of generations per year depends on the temperature. For example, in Florida, there are multiple, overlapping generations and all stages can be found throughout the year. In contrast, there are fewer generations in the northern states. The eggs laid by female scales hatch after 1–3 weeks and the crawlers disperse by moving to other parts of the host plant or spread by wind. After about one week, they become sessile, start feeding and after 10 more days moult to the 2nd instar stage. [4] Second-instars start to develop a scale cover. Female scales moult only one more time and the adults remain within the second-instar exuviae. Male scales moult 3 more times. The total development time from egg hatching to adult females lasts 3–4 weeks. The development of males is slightly longer. There are several generations per year in the southern U.S. with one generation lasting 45 to 65 days. [2] [4] [3]
In North America, ornamental Camellia and Ilex species experience the most serious damage from Fiorinia theae infestations. These plants are widely used in landscaping and the tea scale is a key pest of ornamentals in the south-eastern U.S. In other regions, damage on tea, citrus, dogwood, bottlebrush, kumquat, mango, and olive trees can be also significant. [4] Extensive infestations by the scale insect causes yellowing of the leaves, premature leaf drop and branch dieback, up to death of the host plant. [3] [2]
However, there is a range of susceptibility among ornamental Camellia and Ilex species. For example, in the south-eastern U.S. several non-native species like Camellia japonica or Ilex cornuta are highly susceptible to the scale insect and are often heavily infested. On the other hand, some native species like Ilex vomitoria and Ilex opaca are fairy resistant. [6]
Fiorinia theae infests the lower leaf surface of its host plant, making spraying with pesticides less effective. In addition, chemical pesticides can harm natural enemies and might not be able to penetrate the hard scale cover. [7] [6] The use of horticultural oils is less destructive to beneficial insects, but might not be able to control heavy infestations. [7] Pruning of camellias in spring before the application of pesticides has been suggested for making these more effective. [4] [3]
In south-eastern North America, several wasps like Aphytis diaspidis have been recorded as parasitoids of F. theae. [8] [4] [3] A variety of natural enemies has been reported from India. [9] In 1976, Aphytis theae was released in Florida from India, but did not survive the winter. [10]
Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described.
Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the superfamily Coccoidea due to taxonomic uncertainties. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.
Lepidosaphes ulmi also known as apple mussel scale or oystershell scale is a widely invasive scale insect that is a pest of trees and woody plants. The small insects attach themselves to bark and cause injury by sucking the tree's sap; this metabolic drain on the plant may kill a branch or the entire tree.
The San Jose scale is a hemipterous insect in the family Diaspididae. It is an agricultural pest as it causes damage and crop losses to many fruit crops. In 1914, Q. perniciosus became the first documented case of insecticide resistance.
Aonidiella aurantii or red scale is an armored scale insect and a major pest of citrus. It is thought to be a native of South China but has been widely dispersed by the agency of man through the movement of infected plant material. In the United States it is known as California red scale. It was first found in California between 1868 and 1875, apparently brought there on planting material imported from Australia.
Diaspididae is the largest family of scale insects with over 2650 described species in around 400 genera. As with all scale insects, the female produces a waxy protective scale beneath which it feeds on its host plant. Diaspidid scales are far more substantial than those of most other families, incorporating the exuviae from the first two nymphal instars and sometimes faecal matter and fragments of the host plant. These can be complex and extremely waterproof structures rather resembling a suit of armor. For this reason these insects are commonly referred to as armored scale insects. As it is so robust and firmly attached to the host plant, the scale often persists long after the insect has died.
Eurygaster integriceps is a species of shield bug in the family Scutelleridae, commonly known as the sunn pest or corn bug. It is native to much of northern Africa, the Balkans and western and central Asia. It is a major pest of cereal crops especially wheat, barley and oats.
Aleurocanthus woglumi is a species of whitefly in the family Aleyrodidae. It is a pest of citrus crops, and is commonly known as the citrus blackfly because of its slate-blue colour. It originated in Asia, but has spread to other parts of the world. The parasitic wasps, Encarsia perplexa and Amitus hesperidum can help control the pest.
Aulacaspis yasumatsui, or cycad aulacaspis scale (CAS), is a scale insect species in the genus Aulacaspis that feeds on cycad species such as Cycas revoluta or Dioon purpusii. Other common names include the cycad scale, the sago palm scale, and the Asian cycad scale. This is a serious pest of cycads which can kill its host plant.
Fiorinia is a genus of armored scale insects with around 70 species. The species are widely distributed around the world, however, the large majority of them are found in Asia. They infest woody plants like forest or crop trees, palm trees and shrubs. Several species are invasive and 7 species have been introduced into North America.
Aonidiella orientalis is a species of insect in the family Diaspididae, the armored scale insects. It is known commonly as the Oriental yellow scale. It is an agricultural pest on a wide variety of crop plants.
Aonidiella citrina or yellow scale is an armored scale insect from the family Diaspididae. It feeds by sucking sap from plants in a number of plant families, but is mostly known for being a pest of citrus.
Saissetia coffeae, known generally as hemispherical scale, is a species of soft scale insect in the family Coccidae. Other common names include the helmet scale and coffee brown scale.
Pseudaulacaspis pentagona, the white peach scale or mulberry scale, is a species of armoured scale insect in the family Diaspididae. This scale infests over 100 different genera of plants including many fruit trees and ornamentals.
Hemiberlesia lataniae, the latania or palm scale, is a species of armored scale insect in the family Diaspididae. It was first described by the French entomologist Victor Antoine Signoret in 1869 using Latania lontaroides, a species of palm tree endemic to Réunion as its host; since then, it has been found on avocado trees growing in South Africa, Australia, Israel, the United States, and on a range of other plants in many parts of the world.
Aspidiotus destructor, the coconut scale, is a species of armoured scale insect in the family Diaspididae, found in many tropical and subtropical parts of the world. It is a serious pest of coconut and banana, and attacks a range of other fruiting trees and ornamental plants.
Ceroplastes rubens, known generally as the red wax scale or pink wax scale, is a species of soft scale insect in the family Coccidae. It is native to Australia but has been introduced to other countries, including New Caledonia, Japan, China, Poland and the United States.
Aleurocanthus spiniferus, the citrus spiny whitefly, is an insect native to Asia. It is considered an invasive pest, notably affecting citrus and tea plants. They are part of the whitefly family.
Quadraspidiotus juglansregiae, commonly known as the walnut scale, is a species of armoured scale insect in the family Diaspididae. It is native to North America where it feeds on a wide range of ornamental and forest trees and bushes.
Fiorinia externa, the elongate hemlock scale was accidentally introduced into North America from Japan and is now established in most parts of the north-eastern U.S. It has become a serious pest of hemlock (Tsuga) and some related conifers from the family Pinaceae. Dense colonies of the scale insect result in yellowing, shedding of leaves, dieback and occasional tree death.