Cenopalpus pulcher Canestrini and Fanzago
(Formerly known as Brevipalpus geisenheyneri Baker & Pritchard).
Common name: The flat scarlet mite.
Taxonomic placing: Acari, Prostigmata, Tetranychoidea, Tenuipalpidae.
Geographical distribution: Cosmopolitan, except Australia and New Zealand, and more recently in the western USA.
Host plants: Mainly Rosaceae, especially apple, pear and quince (Cydonia oblonga Mill.), and about 20 other plant species.
Morphology The female body is dark-red, about 0.32 mm in length, the male somewhat smaller. The female dorsum bears large polygonal reticulations that are more prominent at mid-dorsum. The dorsal setae are narrowly lanceolate, the palpi are 4-segmented, and the ventral and genital shields are distinct. The prodorsum of the male is reticulated, whereas the hysteronotum is divided into an anterior reticulated part and a posterior part with only vague lines.
Life history: The flat scarlet mite, which is mostly sedentary, usually raises 2 or 3 annual generations. At 25ºC a generation takes about 6-7 weeks and fecundity comes to 18 eggs/female. The mite often lives in groups, aggregating along the leaves’ midrib, overwintering on the bark of trees and other protected sites. It can survive temperatures as low as -30°C. In spring the mites become active, feed on the foliage and fruits, their numbers peaking in late summer.
Economic importance: The feeding of the mite results in necrotic areas at the bases of the leaves, which then shrivel and may drop prematurely. Feeding on fruits causes severe russet, reductions in quality, and also affects tree health. In some regions it is an important pest of apple, apricot, grape, loquat (Eriobotrya japonica (Thunb.) Lindl.)), quince (Cydonia oblonga Mill.) and pear. Heavy infestations, which appear in mid-summer, are relatively rare.
Chemical control: Chemical treatments (such as white oils or spirotetramat) should be applied after flowering, when the mites are moving from the wood to the foliage. Sulfur is still sometimes used for control.
Biological control: Several Phytoseiidae and Stigmaeidae (such as Agistemus exsertus) attack C. pulcher and sometimes reduce its numbers. The phytoseiid Galendromus (=Typhlodromus) pyri (Scheuten), occurs in selectively sprayed apple orchards in some regions and is the key natural enemy of the pest, because it has developed resistance to organophosphate insecticides. In addition, the pest is preyed on by other generalist predators, such as Aeolothrips intermedius Bagnall (Thysanoptera, anthocorids, mirids and spiders.
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El-Kady, M.H., Hekal, I.H. and Nassar, M.E.S. 1979. Chemical control of flat mite Cenopalpus pulcher (C. and F.) on apple trees (Acarina, Tenuipalpidae). Agricultural Research Review 55: 91-93.
El-Laithy, A.Y. and Fouly, A.H. 1998. Aggregation pattern and minimum size estimates of the false spider mite Brevipalpus pulcher (Acari: Tenuipalpidae) and associated predatory mites in apple orchards. Phytophaga Palermo 8:155-164.
Jeppson, L., Keifer, H., and Baker, E. 1975. Mites Injurious to Economic Plants. University of California Press, Berkeley and Los Angeles, CA., pp.614 + plates.
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