The spider mites Tetranychus urticae Koch and Panonychus ulmi (Koch) (Tetranychidae) cause severe economic losses to vegetable farms and deciduous fruit orchards in Turkey. One of their predators, the ladybird beetle Stethorus gilvifrons (Muls.) (Col., Coccinellidae), aggregates on miteinfested patches of plants. The present study assessed whether there is a role for herbivore-induced plant volatiles (HIPVs) and/or odors emitted directly from these two mite species in the aggregative response of ladybird beetles. The olfactory responses of the predator females to volatiles from T. urticae-and/or P. ulmi-infested sweet pepper (four cultivars, viz. 'Demre', 'Yalova Carliston', 'Kandil Dolma' and 'Yag Biberi'), kidney bean (cv. 'Barbunya') and apple (M9 rootstock) were investigated using a two-choice olfactometer. Our results showed that HIPVs emitted from both T. urticae-and P. ulmi-infested plants significantly attracted S. gilvifrons adults for all plants except the sweet pepper cv. Yag Biberi. In addition, it was found that volatiles from apple plants infested by T. urticae and, especially, P. ulmi are more attractive for S. gilvifrons females than those emitted by other infested plants. The results also suggest that the odors of T. urticae adults and their products might influence the attraction of S. gilvifrons females.

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The effects of Anguina tritici on wheat yields and agronomic components were investigated at Thrace Agricultural Research Institute, Turkey, during the 2013 and 2014 growing seasons. Evaluations during 2013 focused on the wheat cv. Pehlivan, which is widely cultivated in Turkey. In this cultivar, A. tritici led to a grain infection in infected spikes of 0-100%, with an average of 61.8%. In 2014, yield losses caused by A. tritici were investigated in four wheat cvs, Pehlivan, Selimiye, Gelibolu and Kate-A. Results indicated that there were significant yield losses averaging 55% in plots infested with A. tritici (average yields = 3.74 t ha−1), as compared to control plots (average yields = 8.38 t ha−1). Yield losses in the four wheat cvs Kate-A, Pehlivan, Selimiye and Gelibolu were estimated as 51.3, 53.2, 56.6 and 59.6%, respectively, with seed infection levels by A. tritici of 21.4, 20.9, 24.4 and 18.3%, respectively.

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