Phytoparasitica (2003) 31, 144-153

E. Palevsky, O. Ucko, S. Peles, S. Yablonski and U. Gerson (2003)
Species of Oligonychus infesting date palm cultivars in the southern Arava Valley of Israel
Phytoparasitica 31 (2), 144-153
Abstract: In a study of date fruit damage caused by Oligonychus spp., we investigated whether the cultivar affects phenology, and on what hosts the mites over-winter. Samples were taken from 'Deglet Noor', 'Barhi' and 'Medjool' trees from mid-April through mid-September during the years 1999–2002. In the ground-cover mites were monitored by collecting Bermuda grass (Cynodon dactylon) under each sampling tree. Over 99% of the mites collected on Deglet Noor and Barhi fruit were identified as O. afrasiaticus. Mean population levels of O. afrasiaticus reached ten mites or more (initiation of infestation) on Medjool in the second half of May, whereas on Deglet Noor this did not occur before the first week of July. On Barhi the initiation of infestation varied between plots and years, ranging from the second half of May to the beginning of July, but always occurred earlier than Deglet Noor. Mite populations on the pinnae remained low from June through October, not exceeding seven mites per pinna, whereas on fruit strands they reached peak populations of approximately 4000 mites per strand. The sex ratio (proportion of females) of O. afrasiaticus on fruit of all three cultivars was highly female-biased, usually above 0.85. During winter, O. afrasiaticus was found on Bermuda grass in the orchard ground-cover as well as on fronds of all three cultivars.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Eric Palevsky, Uri Gerson

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Oligonychus afrasiaticus	Date palm (Phoenix dactylifera)	Israel