| Tetranychus urticae | |
|---|---|
.jpg) | |
| A red individual | |
 | |
| A yellow individual with two black spots | |
Scientific classification | |
| 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 includered spider mite andtwo-spotted spider mite) is a species of plant-feedingmite generally considered to be apest. It is the most widely known member of the familyTetranychidae orspider mites. Itsgenome was fully sequenced in 2011, and was the first genome sequence from anychelicerate.
T. urticae was originally native only toEurasia, but has acquired acosmopolitan 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 fineweb on and underleaves.[2]
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This spider mite is extremelypolyphagous; it can feed on hundreds of plants, including mostvegetables and food crops – such aspeppers,tomatoes,potatoes,pepinos,beans,maize, andstrawberries, andornamental plants such asroses.[2] It is the most prevalent pest ofWithania somnifera in India.[3] It lays its eggs on the leaves, and it poses a threat to hostplants by suckingcell contents from the leaves cell by cell, leaving tiny pale spots or scars where the greenepidermal 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 thephotosynthetic 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, andchloroplasts.[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 abiological control method, is one of manypredatory mites which prey mainly or exclusively on spider mites.[2]
T. urticae is among the few animals known to synthesisecarotenoids. As inaphids andgall midges, the genes for carotene synthesis appear to have been acquired throughhorizontal gene transfer from a fungus.[6][7][8]
T. urticae reproduces througharrhenotoky, a form of parthenogenesis in which unfertilized eggs develop into males.[9]
Theegg ofT. 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 femalessurvive the winter indiapause.[1]
Inbreeding is detrimental for fitness inT. urticae.[10] Inbred progeny mature more slowly than outbred progeny, and inbred female progeny have lower reproductive output.T. urticae females apparently are capable ofkin recognition and have the ability to avoid inbreeding throughmate choice.[10]
| NCBI ID | 32264 |
|---|---|
| Ploidy | haploid (males) / diploid (females) |
| Genome size | 90.82 Mb |
| Year of completion | 2011 |
Thegenome ofT. urticae was fully sequenced in 2011, and was the first genome sequence from anychelicerate.[11]
