Tetranychus urticae | |
---|---|
A red individual | |
A yellow individual with two black spots | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Trombidiformes |
Family: | Tetranychidae |
Genus: | Tetranychus |
Species: | T. urticae |
Binomial name | |
Tetranychus urticae C. L. Koch, 1836 | |
Tetranychus urticae (common names include red spider mite and two-spotted spider mite) is a species of plant-feeding mite generally considered to be a pest. It is the most widely known member of the family Tetranychidae or spider mites. Its genome was fully sequenced in 2011, and was the first genome sequence from any chelicerate.
T. urticae was originally native only to Eurasia, but has acquired a cosmopolitan distribution as a common pest in a wide range of agricultural systems. [1]
T. urticae is extremely small, barely visible with the naked eye as reddish, yellow or black spots on plants; the adult females measure about 0.4 mm (0.016 in) long. [2] Adult mites sometimes spin a fine web on and under leaves. [2]
This spider mite is extremely polyphagous; it can feed on hundreds of plants, including most vegetables and food crops – such as peppers, tomatoes, potatoes, pepinos, beans, maize, and strawberries, and ornamental plants such as roses. [2] It is the most prevalent pest of Withania somnifera in India. [3] It lays its eggs on the leaves, and it poses a threat to host plants by sucking cell contents from the leaves cell by cell, leaving tiny pale spots or scars where the green epidermal cells have been destroyed. [2] Although the individual lesions are very small, attack by hundreds or thousands of spider mites can cause thousands of lesions, thus can significantly reduce the photosynthetic capability of plants. [2] They feed on single cells which are pierced with a stylet-like mouthpart and the cell contents are removed, they do damage to the spongy mesophyll, palisade parenchyma, and chloroplasts. [4]
T. urticae populations may increase rapidly in hot, dry conditions, expanding to 70 times the original population in as few as six days. [5]
The mite's natural predator, Phytoseiulus persimilis , commonly used as a biological control method, is one of many predatory mites which prey mainly or exclusively on spider mites. [2]
T. urticae is among the few animals known to synthesise carotenoids. As in aphids and gall midges, the genes for carotene synthesis appear to have been acquired through horizontal gene transfer from a fungus. [6] [7] [8]
T. urticae reproduces through arrhenotoky, a form of parthenogenesis in which unfertilized eggs develop into males. [9]
The egg of T. urticae is translucent and pearl-like. [1] It hatches into a larva, and two nymph stages follow: a protonymph, and then a deutonymph, which may display quiescent stages. The adults are typically pale green for most of the year, but later generations are red; mated females survive the winter in diapause. [1]
Inbreeding is detrimental for fitness in T. urticae. [10] Inbred progeny mature more slowly than outbred progeny, and inbred female progeny have lower reproductive output. T. urticae females apparently are capable of kin recognition and have the ability to avoid inbreeding through mate choice. [10]
NCBI genome ID | 2710 |
---|---|
Ploidy | haploid (males) / diploid (females) |
Genome size | 90.82 Mb |
Year of completion | 2011 |
The genome of T. urticae was fully sequenced in 2011, and was the first genome sequence from any chelicerate. [11]
Gossypium is a genus of flowering plants in the tribe Gossypieae of the mallow family, Malvaceae, from which cotton is harvested. It is native to tropical and subtropical regions of the Old and New Worlds. There are about 50 Gossypium species, making it the largest genus in the tribe Gossypieae, and new species continue to be discovered. The name of the genus is derived from the Arabic word goz, which refers to a soft substance.
The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda. Chelicerates include the sea spiders, horseshoe crabs, and arachnids, as well as a number of extinct lineages, such as the eurypterids and chasmataspidids.
Arachnida is a class of joint-legged arthropods, in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons.
Mites are small arachnids. Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as each other's closest relative within Arachnida, rendering the group non-monophyletic. Most mites are tiny, less than 1 mm (0.04 in) in length, and have a simple, unsegmented body plan. The small size of most species makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others are predators or parasites. This last type includes the commercially destructive Varroa parasite of honey bees, as well as scabies mites of humans. Most species are harmless to humans, but a few are associated with allergies or may transmit diseases.
Spider mites are members of the Tetranychidae family, which includes about 1,200 species. They are part of the subclass Acari (mites). Spider mites generally live on the undersides of leaves of plants, where they may spin protective silk webs, and can cause damage by puncturing the plant cells to feed. Spider mites are known to feed on several hundred species of plants.
Withania somnifera, known commonly as ashwagandha or winter cherry, is an evergreen shrub in the Solanaceae or nightshade family that grows in India, the Middle East, and parts of Africa. Several other species in the genus Withania are morphologically similar.
The Acariformes, also known as the Actinotrichida, are the more diverse of the two superorders of mites. Over 32,000 described species are found in 351 families, with an estimated total of 440,000 to 929,000 species, including undescribed species.
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan.
Feltiella acarisuga is a species of predatory gall midges which will feed on various species of spider mites. It is especially common when spider mites occur in colonies. It requires a high spider mite density and high humidities to become established.
Aceria sheldoni, commonly called the citrus bud mite, is a species of mite belonging to the family Eriophyidae. It feeds in leaf- and flower-buds of Citrus spp., causing deformation to leaves, flowers and fruit, and is a worldwide pest of citrus fruit production.
Inherited sterility in insects is induced by substerilizing doses of ionizing radiation. When partially sterile males mate with wild females, the radiation-induced deleterious effects are inherited by the F1 generation. As a result, egg hatch is reduced and the resulting offspring are both highly sterile and predominately male. Compared with the high radiation required to achieve full sterility in Lepidoptera, the lower dose of radiation used to induce F1 sterility increases the quality and competitiveness of the released insects as measured by improved dispersal after release, increased mating ability, and superior sperm competition.
Orius insidiosus, common name the insidious flower bug, is a species of minute pirate bug, a predatory insect in the order Hemiptera. They are considered beneficial, as they feed on small pest arthropods and their eggs. They are mass-reared for use in the biological control of thrips.
Neoseiulus californicus is a predatory mite that feeds on Tetranychid mites. This species was first described on lemons from California under the name Typhlodromus californicus in 1954.
Acyrthosiphon pisum, commonly known as the pea aphid, is a sap-sucking insect in the family Aphididae. It feeds on several species of legumes worldwide, including forage crops, such as pea, clover, alfalfa, and broad bean, and ranks among the aphid species of major agronomical importance. The pea aphid is a model organism for biological study whose genome has been sequenced and annotated.
Dicyphus hesperus is a species of true bug in the family Miridae. It is a generalist predator of other insects and also feeds on plant tissues. It is native to North America and has been used there in biological control of agricultural pests, especially whitefly on tomatoes.
Tebufenpyrad is an insecticide and acaricide widely used in greenhouses. It is a white solid chemical with a slight aromatic smell. It is soluble in water and also in organic solvents.
Oligonychus pratensis, the Banks grass mite, is a species of mite in the spider mite family. They are considered a pest and often infest corn and turf grasses.
Cannabis (/ˈkænəbɪs/) is commonly known as marijuana or hemp and has two known strains: Cannabis sativa and Cannabis indica, both of which produce chemicals to deter herbivory. The chemical composition includes specialized terpenes and cannabinoids, mainly tetrahydrocannabinol (THC), and cannabidiol (CBD). These substances play a role in defending the plant from pathogens including insects, fungi, viruses and bacteria. THC and CBD are stored mostly in the trichomes of the plant, and can cause psychological and physical impairment in the user, via the endocannabinoid system and unique receptors. THC increases dopamine levels in the brain, which attributes to the euphoric and relaxed feelings cannabis provides. As THC is a secondary metabolite, it poses no known effects towards plant development, growth, and reproduction. However, some studies show secondary metabolites such as cannabinoids, flavonoids, and terpenes are used as defense mechanisms against biotic and abiotic environmental stressors.
Trombidium grandissimum, commonly known as the giant red velvet mite, is a species of mite in the genus Trombidium in the family Trombidiidae. This common mite is endemic to northern and central India, especially in the central plateau, and it primarily inhabits arid regions. T. grandissimum live on the ground and often hidden among soil, but is commonly seen during the rainy season or after recent rain events, and therefore has the nickname of "rain bug".