Investigation of thrips (Thysanoptera) species, population changes and thrips damage in lemon and orange groves in Yüreğir district of Adana province

In this thesis study; Thysanoptera species, population changes and possible damages in lemon and orange groves in Yüregir District of Adana Province, Türkiye were investigated in 2022 and 2023. Nine species were identified in the flowering shoots in the lemon garden, eight in the yellow sticky traps, and six species in the flowering shoots and yellow sticky traps in the orange garden. The first species seen in the flowers of lemon and orange trees were usually adult individuals of the Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Predatory thrips, Scolothrips longicornis Priesner (Thysanoptera: Thripidae) was detected in high density in the flowers of orange trees. Thrips were sampled mainly from flowers, and no thrips adult or larvae was found in young fruits. It has been determined that the development of thrips species depends on the flowering phenology of lemon and orange trees. The first thrips species infesting flowers in lemon and orange gardens was F. occidentalis. Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae), known as Hawaiian flower thrips, was recorded at relatively higher densities in June flowers in the lemon garden, with the highest average number of individuals being 20-25 individuals/4 flowering shoots. Frankliniella occidentalis larvae were mostly detected in spring, when the flower petals were falling off. Thrips hawaiiensis larvae were mostly recorded in June flowers. The rate of scarred fruits resulting from thrips feeding in the lemon garden was quite low, with an average of 0.08%. For this reason, it is recommended that F. occidentalis, especially in spring flowers, should not be considered as a harmful species. For the sampled region, it does not seem meaningful to apply chemicals against thrips, including T. hawaiiensis, especially in Meyer lemons and orange trees, in the spring and early summer (June). It was concluded that trap and flower sampling are not always compatible in terms of monitoring thrips population changes, there are differences, and therefore, it would be more appropriate to use both sampling methods together instead of a single sampling method.