A reservoir weed for mites: Datura stramonium L. (Solanaceae) in the vicinity of cultivated solanaceous plants in Turkey

Abstract

Twenty-six phytophagous, predacious and generalist mite species were found on the weed species Datura stramonium in the vicinity of solanaceous vegetables from two locations in Turkey during 2009-2010. Of seven species of phytophagous mites, Tetranychus urticae was the predominant species on the weed leaves. Additionally, 15 predacious mite species from seven families were identified: Phytoseiidae, Anystidae, Stigmaeidae, Bdellidae, Ascidae, Ameroseiidae and Iolinidae. Phytoseiidae (nine species) and Iolinidae (one species) were the most abundant predacious mites in the families. The dominant predacious species were Cydnodromus californicus and Pronematus ubiquitus. The Shannon index (H '), a biodiversity parameter of the predacious mites was very high compared to that of phytophagous mites that occurred at a high density. Among four generalist species from three families (Tydeidae, Acaridae and Oribatidae), one species, Zygoribatula microporosa, was found in the Turkish mite fauna. In Ankara, the population density of spider mites on the weed leaves began to increase in early July and peaked three times in late July, early September and mid-October in 2009-2010. In Bursa, the mites emerged in early June and peaked four times in early July, early August, early September and early October in 2010-2011. Cydnodromus californicus and Typhlodromus Anthoseius recki exhibited efficient numerical responses to spider mite populations from early August to early September. However, in Bursa, Sorenson's coefficient confirmed that there were positive predator-prey associations among spider mites and these predacious mites. Although this weed is a source of predacious species when it is located in the vicinity of tomato fields, D. stramonium may play a role as a reservoir plant for phytophagous mites and permit increasing pest population in areas used for the cultivation of solanaceous vegetables due to predators' delayed response to spider mite populations.