Tenuipalpus granati Sayed
Taxonomic placing: Acari, Prostigmata, Tetranychoidea, Tenuipalpidae.
Common name: Pomegranate mite.
Geographical distribution: East Mediterranean countries to southern Russia.
Host plants: Grapes, pomegranate, pistachio (Pistacia vera L.).
Morphology: The anterior part of the body is broad whereas the posterior is narrow and carries 3-4 pairs of simple setae and one pair of longer, flagellate setae. The palpi are 3-segmented, the dorsum is almost smooth with only a few longitudinal markings, and its central area (dorsocental) bears only a single pair of setae.
Life cycle: Females, which are thelytokous, produce about 18 red eggs each, placing them in protected sites, such as bud axes and shoot cracks. The active mite stages prefer the lower leaf sides. Their populations increase during spring, peak in mid-summer, decline in winter.
Economic importance: Mite feeding results in grape leaf curling and browning; severe infestations cause early leaf drop, reducing the yield. The grape varieties mostly affected are Semyon and Alphonse. Pistachio trees may also shed their leaves with subsequent yield losses. The pest also occurs on the aerial parts of pomegranate trees without causing much apparent damage.
Management
Plant resistance: Mite larvae died after feeding for one day on the Egyptian variety Elgharibi, and adults after 1.5 days, laying very few eggs. On the Romey Red variety the immature stages developed well and females lived for 17.5 days, laying an average of 17 eggs.
Chemical control: Several acaricides may control the pest; best results were obtained with the organochlorid dicofol (0.2%) applied in late summer.
References
Jeppson, L.R., Keifer, H.H. and Baker, E.W. 1975. Mites Injurious to Economic Plants. University California Press, Berkeley, California.
Mehrnejad, M.R. and Ueckermann, E. A. 2001. Mites (Arthropoda, Acari) associated with pistachio trees (Anacardiaceae) in Iran (I). Systematic & Applied Acarology Special Publications 6: 1-12.
Sternlicht, M. and Golan, Y. 1967. Experiments in the control of the pomegranate mite, Tenuipalpus granati Sayed, a pest of vineyards in Israel. Israel Journal of Agricultural Research 17: 95-99.
Yousef, A.A., Zaher, M.A. and Abd-el-Hafiez, A.M. 1980. Effect of season and grapevine variety on the biology of Tenuipalpus granati Sayed, with description of its immature stages (Acari: Prostigmata: Tenuipalpidae). Acarologia 21: 384-388.