Eotetranychus uncatus Garman

Taxonomic placing: Acari, Prostigmata, Tetranychoidea, Tetranychidae.

Common name: Garman spider mite.

Hosts: About 40 plant species, especially apple and plum.

Distribution: North and South America, Europe, Iran, India, China and Japan.

Morphology: The body female pale-green, about 0.3 mm in length, and with 13 pairs of simple dorsal setae.

Life history: Eotetranychus uncatus overwinters as adult females, which continue to feed as long as foliage is available, despite low temperature. Clusters of the females occur under loose bark scales or other shelters. They return to activity when days become warmer, raising a generation in 1-2 weeks and spinning copious amounts of webs. They produce about 26 eggs/female and live for 2 weeks at 20-25°C. Their best host plants are certain apple and plum cultivars.

Economic Importance: The mites feed mostly on the lower leaf surfaces, causing blotching or stippling, resulting in the uneven growth of the two surfaces and crinkling. In heavy infestations the leaves become bronzed. Severely attacked trees may lose their leaves, which affects the amount and size of the fruits.

Management

Effect of pesticides: Most common insecticides controlled E. uncatus, but treatments with the organochloride DDT or the fungicide captan, as well as other chemicals, resulted in mite outbreaks.

Biological control: Several phytoseiids feed on E. uncatus and may control it in different parts of the world, especially in unsprayed orchards.

References

Gotoh, T. 1987. Annual life cycle of the spider mite, Eotetranychus uncatus Garman (Acarina: Tetranychidae). Applied Entomology and Zoology 22: 52-58.

Oatman, E.R. 1973. An ecological study of arthropod populations on apple in Northeastern Wisconsin: population dynamics of mite species on the foliage. Annals of the Entomological Society of America 66: 122–131.

Skorupska, A. 1993. Biology and ecology of Eotetranychus uncatus Garman. II. The influence of temperature on the biology of the red spider mite (Eotetranychus uncatus Garman). Prace Naukowe Instytutu Ochrony Roslin 33: 71-77.

Skorupska, A. 1994. Biology and ecology of Eotetranychus uncatus Garman (Tetranychidae, Acarina). III. The influence of host plants on the biology and demographic parameters of the apple spider mite (Eotetranychus uncatus Garman). Prace Naukowe Instytutu Ochrony Roslin 35: 26-32.

Ubertalli, J.A. 1955. Life History of Eotetranychus uncatus Garman. Journal of Economic Entomology 48: 47-49.

Yanar, D. 2012. Life-history parameters of Eotetranychus uncatus Garman (Acari: Tetranychidae) on red delicious apple. Pakistan Journal of Zoology 44: 129-132.

Yanar, D. and Ecevit, O. 2008. Species composition and seasonal occurrence of spider mites and their predators in sprayed and unsprayed apple orchards in Tokat, Turkey. Phytoparasitica 36: 491-501.