The fatty acid compositions of phospholipid subclasses in various development stages of Sunn pest, Eurygaster integriceps Put. (Heteroptera: Scutelleridae)

ABSTRACT THE FATTY ACID COMPOSITIONS OF PHOSPHOLIPID SUBCLASSES IN VARIOUS DEVELOPMENT STAGES OF SUNN PEST, EURYGASTER INTEGRICEPS PUT. (HETEROPTERA: SCUTELLERIDAE) MASTER THESIS Mehmet Cemal TALAY INSTITUTE OF NATURAL AND APPLIED SCIENCES UNIVERSITY OF DICLE 2019 In this study, fatty acid compositions of phospholipid (PL) subclasses such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylserine (PS) of various development stages of sunn pest Eurygaster integriceps such as eggs, nymph, new-generation adult, prediapausing adult and postdiapausing adult were investigated. Phospholipid subclasses from E. integriceps egg, nymphs and adults contained variable distributions of ten fatty acids: the saturated fatty acids (SFAs), myristic acid (14:0), pentadecanoic acid (15:0), palmitic acid (16:0), stearic acid (18:0), the monounsaturated fatty acids (MUFAs), palmitoleic acid (16:1n-7), oleic acid (18:1n-9); and the polyunsaturated fatty acids (PUFAs), linoleic acid (18:2n-6), α-linolenic acid (18:3n-3), arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-3). The dominant fatty acids observed in PL subclasses from various development stages of E. integriceps were 16:0 among SFA, 18:1n-9 among MUFA and 18:2n-6 among PUFA. It was found that the changes in fatty acid compositions from the PC fractions of prediapausing and postdiapausing adults were similar to those for the PE fractions. In both fractions of post-diapausing adults, 16:0, 18:0 and ∑ SFA lower, 16:1n-7 and 18:2n-6 were determined at a higher percentage compared to pre-diapausing adults. Compared to other developmental stages, phosphatidylcholine subclass in egg was found to be higher in terms of 18:1-9 and MUFA, and lower in 18:2n-6 and PUFA. It was found that 18:1n-9 and ∑MUFA were significantly higher in PE fraction of the new-generation adults compared to the another development stages whereas 18:2n-6 and ∑PUFA were lower. Compared to the pre-diapausing adults, the ratio of unsaturated fatty acids to saturated fatty acids (UFA)/ (SFA) was found to be higher in all phospholipid subclasses of the post-diapausing adults.