The Effects of the Essential Oils Isolated from Four Ecotypes of Cumin (Cuminum cyminum L.) on the Blood Cells of the Pink Stem Borer, Sesamia cretica Ledere (Lepidoptera: Noctuidae)

Abstract

ABSTRACT: In this research, the effects of essential oils isolated from four ecotypes of cumin (Cuminum cyminum L.) Northern-Khorasan (NS), Fars (FS), Kerman (KK), and Kerman (KR) were evaluated on the 4th instar larvae of pink stem borer, Sesamia cretica Lederer. The essential oils were extracted from seeds and the chemical composition was assessed via Gas Chromatography-Mass Spectrometry (GC-MS). Cuminaldehyde (43.599-55.939%), γ-terpinene (13.134-21.750%), m-cymene (8.349-16.935%), ß-pinene (6.320-14.130%), and α-phellandrene (2.137-4.742%) were the main components of the essential oils. Four types of blood cells: prohaemocytes, plasmatocyte, granulocyte, and oenocytoid were identified in the haemolymph of the 4th instar larvae of S. cretica. The decreasing haemocyte counts were found to be significant in the different ecotypes of C. cyminum essential oil. The utilized concentrations and specified times had significant effects on the reductions of the mentioned cell numbers. The fewest number of cells for all ecotypes was measured after 48 h. The highest decline in the total haemocyte count was related to the concentration of 8000 ppm in NS ecotype. The lowest LC50 value was observed in KR ecotype. Based on the results of the present study, the essential oils isolated from the different ecotypes of C. cyminum showed to be promising candidates for S. cretica management.