''Tetranychus urticae'' (

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

s include red spider mite and two-spotted spider mite) is a species of plant-feeding mite generally considered to be a

pest Pest or The Pest may refer to: Science and medicine * Pest (organism), an animal or plant deemed to be detrimental to humans or human concerns ** Weed, a plant considered undesirable * Infectious disease, an illness resulting from an infection ** ...

. It is the most widely known member of the family

Tetranychidae Spider mites are members of the Tetranychidae family, which includes about 1,200 species. They are part of the subclass Mite, Acari (mites). Spider mites generally live on the undersides of leaf, leaves of plants, where they may spin protective s ...

spider mite 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, a ...

s. Its genome was fully sequenced in 2011, and was the first genome sequence from any

chelicerate The subphylum Chelicerata (from New Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, and mite ...

Distribution

''T. urticae'' was originally native only to Eurasia, but has acquired a

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

Description

''T. urticae'' is extremely small, barely visible with the naked eye as reddish or greenish spots on leaves and stems; the adult females measure about long. The red spider mite, which can be seen in

greenhouse A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of Transparent ceramics, transparent material, such as glass, in which plants requiring regulated climatic condit ...

s and tropical and temperate zones, spins a fine

web Web most often refers to: * Spider web, a silken structure created by the animal * World Wide Web or the Web, an Internet-based hypertext system Web, WEB, or the Web may also refer to: Computing * WEB, a literate programming system created by ...

on and under

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

Ecology

This spider mite is extremely

polyphagous Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...

; it can feed on hundreds of plants, including most vegetables and food crops – such as peppers, tomatoes, potatoes, pepinos,

bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

s, maize, and

strawberries The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely ap ...

, and ornamental plants such as roses. It is the most prevalent pest of '' Withania somnifera'' in India. 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. 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 Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

capability of plants. 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. The mite's natural predator, ''

Phytoseiulus persimilis ''Phytoseiulus'' is a genus of mites in the Phytoseiidae family. A predatory mite, this is the mite predator most frequently used to control two-spotted spider mites in greenhouses and outdoor crops grown in mild environments. This mite was acci ...

'', commonly used as a biological control method, is one of many predatory mites which prey mainly or exclusively on spider mites. Other than certain aphids, ''T. urticae'' is the only animal known to be able to synthesise

carotenoid Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...

s. As in aphids, the genes for carotene synthesis appear to have been acquired through horizontal gene transfer from a fungus.

Lifecycle

''T. urticae'' reproduces through arrhenotoky, a form of parthenogenesis in which unfertilized eggs develop into males. The

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

of ''T. urticae'' is translucent and pearl-like. 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.

Inbreeding avoidance

Inbreeding is detrimental for fitness in ''T. urticae''. 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 Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choic ...

Genomics

The genome of ''T. urticae'' was fully sequenced in 2011, and was the first genome sequence from any

References

External links

MEMS Movie Gallery
spider mite used for demonstrating

microelectromechanical systems Microelectromechanical systems (MEMS), also written as micro-electro-mechanical systems (or microelectronic and microelectromechanical systems) and the related micromechatronics and microsystems constitute the technology of microscopic devices, ...

technology
Early Signs Of Spider Mites
{{Authority control Trombidiformes Agricultural pest mites Grape pests Animals described in 1836 Arachnids of Asia Taxa named by Carl Ludwig Koch