Apple mussel scale | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hemiptera |
Suborder: | Sternorrhyncha |
Family: | Diaspididae |
Genus: | Lepidosaphes |
Species: | L. ulmi |
Binomial name | |
Lepidosaphes ulmi (Linnaeus, 1758) | |
Lepidosaphes ulmi also known as apple mussel scale or oystershell scale is a 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 adult female oystershell scale is up to four millimetres long, elongated, tapering to a point at the posterior end and often slightly curved, somewhat resembling a mussel shell. The upper side is a banded, brown, waxy scale and the underside is cream coloured. There are no eyes or legs and the short antennae have only a single segment. The mandibles are lengthened into a stylet adapted for sucking sap. The female lays about one hundred oval white eggs, retaining them under her body, and then dies. Her scale darkens in colour and stays in place, protecting the eggs over the winter. They can survive temperatures as low as -32 °C. [1] They hatch in the spring at about the time the host plant's buds are bursting. The crawlers are tiny and disperse on the host, each one looking for a suitable protected site with thin bark in which to settle, remaining in that place permanently after sinking the stylet into the host plant's vascular tissues. [2] The crawler moults twice before becoming an adult female, forming a protective scale from larval exuviae and secretions. Some crawlers may develop into males. These undergo four moults and the adult males have eyes, three pairs of legs, one pair of wings, a head and a body divided into a thorax and abdomen. Not all colonies produce males and bisexual and parthenogenetic populations are known. [1]
Over one hundred and fifty host plant species are known for the oystershell scale including members of the families Aceraceae, Betulaceae, Caprifoliaceae, Celastraceae, Elaeagnaceae, Grossulariaceae, Hydrangeaceae, Juglandaceae, Oleaceae, Pyrolaceae, Rosaceae, Salicaceae and Tiliaceae. Apart from forest trees and ornamentals, the oystershell scale is a pest of apples, pears, plums, peaches, apricots, mulberries and currants. It infests trunks and branches but is not found on leaves. Heavy infestations can kill branches and even cause trees to die. [1]
The crawlers are vulnerable to a number of pesticides but adult oystershell scales are protected by their waxy scales which repel water. Use of horticultural oils may overcome this problem but control is still difficult. In gardens, trunks and branches may be scrubbed and heavily infested wood pruned out and removed. [2] In some parts of the world, populations are controlled to a certain extent by the oystershell scale parasitoid, Aphytis mytilaspidis [3] and the ladybird Chilocorus bipustulatus . [1]
Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera. Many insects commonly known as "bugs", especially in American English, belong to other orders; for example, the lovebug is a fly and the May bug and ladybug are beetles.
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.
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.
Maconellicoccus hirsutus, is a pest of many plants, trees, and shrubs. It infests hibiscus, citrus, coffee, sugar cane, annonas, plums, guava, mango, okra, sorrel, teak, mora, pigeon pea, peanut, grapevine, maize, asparagus, chrysanthemum, beans, cotton, soybean, cocoa, and many other plants. The pest forms colonies on the host plant, and if left undisturbed, the colonies will grow into large masses of white waxy coverings on branches, fruiting structures, leaves, and even whole plants, including large trees.
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.
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.
Coccus viridis is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as green scale or sometimes coffee green scale because it is a major pest of coffee crops throughout the world.
Cryptococcus fagisuga, commonly known as the beech scale or woolly beech scale, is a felted scale insect in the superfamily Coccoidea that infests beech trees of the genus Fagus. It is associated with the transmission of beech bark disease because the puncture holes it makes in the bark allow entry of pathogenic fungi which have been identified as Nectria coccinea var. faginata and sometimes Nectria galligena.
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.
Coccus hesperidum is a soft scale insect in the family Coccidae with a wide host range. It is commonly known as brown soft scale. It has a cosmopolitan distribution and feeds on many different host plants. It is an agricultural pest, particularly of citrus and commercial greenhouse crops.
Eriosoma lanigerum, the woolly apple aphid, woolly aphid or American blight, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants.
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.
Pulvinaria regalis is a species of scale insect in the family Coccidae. Although it is commonly known as the horse chestnut scale, it affects other trees besides horse chestnuts as well as many species of woody shrubs. Adults are normally all female and produce eggs by parthenogenesis. The insects are thought to have originated in Asia but arrived in Europe in the second half of the twentieth century.
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.
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.
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.
Carulaspis minima is an armoured scale insect, in the subtribe Diaspidina of the family Diaspididae, and is commonly known as the minute cypress scale. It was first described in 1869 by the French entomologist Victor Antoine Signoret. It feeds on evergreen conifers in the families Cephalotaxaceae, Cupressaceae and Taxodiaceae.
Planococcus ficus, commonly known as the vine mealybug, is a species of mealybug, belonging to the family Pseudococcidae, native to tropical and subtropical regions. The vine mealybug is found in Europe, Northern Africa, Southern Africa, the Americas, and the Middle East. The vine mealybug is invasive to weedy plants in many different regions of the world.