The effect of different eggplant varieties on Epitrix hirtipennis Melsheimer (Coleoptera: Chrysomelidae) and predators and investigation of control methods

In this study, the effects of climate, year and variety on the population development of Epitrix hirtipennis on the 4 eggplant varieties (Kemer (Savcili), Topan, Aydın Black, Seyhkent) were investigated in Dicle University Faculty of Agriculture Practice Field in the 2014 and 2015 growing seasons. The study was conducted with randomized block design with four replications. In the study which was conducted under laboratory conditions, the nutrition preference among eggplant varieties was determined by the dry weight biomass method, and furthermore, alternative pest control methods were investigated. Predators of the pest also were identified in the study. It was observed that the pest emerged in July in the first year and in June in the second year in the nature in Diyarbakır. There were statistically significant differences between the varieties of the populations of Epitrix hirtipennis in both visual measurements and the controls with yellow sticky traps. In both years Epitrix hirtipennis adults were observed greater in the Kemer (Savcili) variety than the others. It was found that there were statistically significant (p <0.05) differences in the nutrition preference of Epitrix hirtipennis between young and old leaves and varieties. In the study, it was observed that the young plants of the eggplant species were more preferred. When the average amount of nutrients consumed per pest among young eggplants are examined from highest to lowest, it was found to be Topan, Şeyhkent, Kemer (Sivcili) and Aydn Black respectively. In the samples taken from the old leaves, the average amount of nutrients consumed per pest was listed as Kemer (Savcılı), Topan, Aydın Black, Şeyhkent from highest to lowest. Natural and chemical pesticide trials were conducted in laboratory determine alternative control opportunities against Epitrix hirtipennis. When the LD50 values obtained as a result of the tests run in the form of immersion in adults in comparison to the results obtained in the study were evaluated amongst themselves in terms of essential oils, it was found to be Thyme(0.32%)> Mint (0.38%)> Lavender (0.58%). On the other hand, the LD50 values obtained as a result of the spray tests to adults were found to be Thyme (0.33%)> Mint (0.39%)> Lavender (0.61%). When the pest movement data are examined for 6, 12, 24, 48 and 72 hours within the scope of repellent impact trials, the thyme essential oil has shown a rather effective performance with 92% repellent impact. This was followed by mint(84%), NeemAzal T/S (73%) and lavender (65%). Although many species belonging to the coccinellidae family were identified in the study, it was found in the visual controls that the species from the Nabidae family were fed with (Himacerus apterus and Nabis alternatus) Epitrix hirtipennis.