Two spotted Spider Mites

Damage

Two spotted spider mites are one of the most damaging pests of different field, fruit and vegetable crops, and ornamental plants. Two spotted spider mites feed by sucking cell sap (juice) from leaves and succulent twigs of their host plants. Feeding injuries caused by these mites generally give mottled and speckled (Photo 1) appearances to host leaves as well as affect the process of photosynthesis, which in turn reduces plant’s ability to make its own food. Heavy infestations of these mites generally result into leaf yellowing and desiccation, leaf drop, death of plant and yield loss of many crops like beans, canola, cotton, citrus, cucumber, eggplant, melon, peanut, pepper, strawberries, potato, soybean and tomato. While feeding, both adults and nymphs of this mite also produce webbing on the leaves and small branches with the fine strands (Photo 2) that reduces aesthetic value of many ornamental plants including azalea, camellia, hollies, ligustrum, roses and viburnum. The damage caused by two spotted spider mites can cause in millions of dollars loss to agricultural, horticultural and ornamental industries.

Facts (show all)

+ Taxonomy

• Common name: Red spider mite, Spider mites or two spotted spider mites.
• Scientific name: Tetranychus urticae
• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Arachnida
• Order: Trombidiformes
• Suborder: Prostigmata
• Family: Tetranychidae
• Subfamily: Tetranychinae
• Genus: Tetranychus
• Species: T. urticae

+ Identification

Adults: Adult mites are very tiny about 1/20 inch long, oval shaped with four pairs of legs and two red spots. Depending upon the species, mites can be brown, green, red or yellow in color. The color of mites may also change with the season.

Eggs: Mite eggs are translucent and spherical in shape and as large as the size of adult mites.

Larvae: Mite larvae resemble to their parents but they are comparatively very small with only three pairs of legs.

Nymphs: Nymphs also resemble to their but they are larger than larval stages and smaller than adult stages. There are two nymphal stages; first stage is called protonymph and second stage is deutonymph. Like their parents, they have four pairs of legs.

Pupae: Pupal stage is not present in the life cycle of spider mites.

+ Biology

Life cycle of two spotted mites consists of four stages including eggs, larvae, nymphs and adults. These mites overwinter as mated females (quiescent stages) under the tree bark and/or plant debris on the ground. Early in the spring, mated females lay hundreds of eggs on the leaves of host plants. Eggs hatch within 2-3 days into small larvae that molt into first nymphal stage called protonymph within next 2 days. The first nymphal stage then molt into second nyhmpal stage called deutonymph within 1-3 days. The deutonymphs then molt into adult stages within 2 day. Thus, under favorable climatic conditions, spider mites can complete their life cycle within 5- 20 days.

+ Biological control

Currently several chemical acaricides (pesticides) are available for the control of pest mites but their use is restricted in organic gardens due to their detrimental effects on human and animal health, and the environment. Therefore, natural enemies such as predatory mites (Amblyseius swirskii, Neoseiulus californicus, Neoseiulus fallacis, Phytoseiulus persimilis, Stratiolaelaps scimitus (Hypoaspis miles, and Western predatory Mite, Galendromus occidentalisand) and predatory insects including gall midge (Feltiella acarisuga), minute pirate bug (Orius insidiosus) and predatory bug (Dicyphus hesperusare) are currently used as environment and human friendly biological control alternatives to chemical pesticides to control two spotted spider mites.

+ Beneficial predatory mites

• Amblyseius andersoni
• Amblyseius swirskii
• Neoseiulus californicus
• Neoseiulus fallacis
• Phytoseiulus persimilis
• Stratiolaelaps scimitus (Hypoaspis miles)
• Westeren Predatory Mite, Galendromus occidentalis

+ Beneficial predatory insects

• Gall midge flies, Feltiella acarisuga
• Minute pirate bug, Orius insidiosus
• Predatory bug, Steinernema feltiae

+ Research Papers

Barber, A., Campbell, C.A.M., Crane, H., Lilley, R. and Tregidga, E. 2003. Biocontrol of two-spotted spider mite Tetranychus urticae on dwarf hops by the phytoseiid mites Phytoseiulus persimilis and Neoseiulus californicus. Biocontrol Science and Technology 13: 275-284.

Coop, L.B. and Croft, B.A. 1995. Neoseiulus fallacis: dispersal and biological control of Tetranychus urticae following minimal inoculations into a strawberry field. Experimental and Applied Acarology 19: 31-43.

de Almeida, A.A. and Janssen, A. 2013. Juvenile prey induce antipredator behaviour in adult predators. Experimental and Applied Acarology 59: 275- 282.

Gotoh, T. Yamaguchi, K. and Mori, K. 2004. Effect of temperature on life history of the predatory mite Amblyseius (Neoseiulus) californicus (Acari: Phytoseiidae). Experimental and Applied Acarology 32: 15-30.

Kerguelena, V. and Hoddlea, M.S. 1999. Biological control of Oligonychus perseae (Acari: Tetranychidae) on avocado: II. Evaluating the efficacy of Galendromus helveolus and Neoseiulus californicus (Acari: Phytoseiidae). International Journal of Acarology 25:221-229.

Nicetic, O., Watson, D.M., Beattie, G.A.C., Meats, A. and Zheng, J. 2001. Integrated pest management of two-spotted mite Tetranychus urticae on greenhouse roses using petroleum spray oil and the predatory mite Phytoseiulus persimilis. Experimental and Applied Acarology 25: 37-53.

Onzo, A., Houedokoho, A.F. and Hanna, R. 2012. Potential of the predatory mite, Amblyseius swirskiia to suppress the broad mite, Polyphagotarsonemus latus on the eggplant, Solanum macrocarpon. Journal of Insect Science 12 Article Number: 7.

Osborne, L. S. and Petitt, F. L. 1985. Insecticidal Soap and the Predatory Mite, Phytoseiulus persimilis (Acari: Phytoseiidae), Used in Management of the Two spotted Spider Mite (Acari: Tetranychidae) on Greenhouse Grown Foliage Plants. Journal of Economic Entomology 78: 687-691.

Park, H.H., Shipp, L., Buitenhuis, R. and Ahn, J.J. 2011. Life history parameters of a commercially available Amblyseius swirskiia(Acari: Phytoseiidae) fed on cattail (Typha latifolia) pollen and tomato russet mite (Aculops lycopersici). Journal of Asia-pacific Entomology 14: 497-501.

Strong, W.B., Croft, B.A. and Slone, D.H. 1997. Spatial Aggregation and Refugia of the Mites Tetranychus urticae and Neoseiulus fallacis(Acari: Tetranychidae, Phytoseiidae) on Hop. Environmental Entomology 26: 859-865.

Xiao, Y.F., Avery, P., Chen, J.J., McKenzie, C. and Osborne, L. 2012. Ornamental pepper as banker plants for establishment of Amblyseius swirskiia (Acari: Phytoseiidae) for biological control of multiple pests in greenhouse vegetable production. Biological Control 63: 279-286.

Xu, X. and Enkegaard, A. 2010. Prey preference of the predatory mite, Amblyseius swirskiia between first instar western flower thrips Frankliniella occidentalis and nymphs of the two spotted spider mite Tetranychus urticae. Journal of Insect Science 10:149.

The following beneficial organisms can control the plant feeding spider mites