Composition and seasonal abundance of mites on three citrus species in Greece.

In order to compare the composition and the relative abundance of the mite species occurring on three citrus species, sweet orange, sour orange and mandarin, 25 monthly samplings were conducted on mandarin in a citrus orange orchard in Argolis county, Greece, from June 2004 to June 2006. In the examined samples, mites from 15 taxa belonging to 3 orders were identified. These included nine predatory taxa belonging to three families (Phytoseiidae, Cheyletidae, Bdellidae), four primarily fungivorous taxa in the family Tydeidae and Tarsonemidae, two phytophagous taxa belonging to families Tetranychidae and Eriophyidae and one saprophagous taxon (Cryptostigmata). From the aforementioned taxa, 14 were found on sour orange, 13 on sweet orange and 9 on mandarin.Tydeus californicuswas the only “dominant and constant” taxon in all the three citrus species.Lorryiasp. nr.formosawas “dominant and constant” on mandarin, while on sweet orange was “recedent and constant” and on sour orange was “influent and accessory”.Aceria sheldoniwas “dominant and accessory” on sour orange, while it was “recedent and accidental” on sweet orange and totally absent on mandarin. All the other taxa were “influent”, or “recedent”. Population ofTydeus californicusin all citrus species was higher in fall, winter and early spring, while in summer it was declining. The mean population level on sweet orange was significantly higher compared with mandarin. A similar population pattern was observed inL.sp. nr.formosa, with the expectance of mandarin during 2005. Tetranychid population on sweet orange was the highest, but no significant difference was observed on the other two species. TheA. sheldonipopulation was significantly higher on sour orange compared with sweet orange, while on mandarin was absent. Also, predatory mites’ population was significantly higher on sour orange than on sweet orange and mandarin. They were present in the samples for long periods in all citrus species. [ABSTRACT FROM PUBLISHER]