Host Nutrition vis-a-vis Fatty Acid Profile and Reproductive Biology of Fall Armyworm, Spodoptera frugiperda (J.E. Smith)

Abstract

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a notorious invasive insect pest of many important agricultural crops. Fatty acids play a major role in various physiological processes of the insects which are essential for growth, development and overall insect fitness. The present study was conducted to understand the effect of different hosts such as meridic diet, baby corn and castor on fatty acid profile and on biology of the fall armyworm. The highest per cent of polyunsaturated fatty acid (PUFA) viz., linoleic acid was recorded in adults of meridic diet fed larvae both in male (44.18 ± 0.02) and females (39.84 ± 0.13) as compared to saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Highest saturated fatty acids such as palmitic (16:0) and stearic acid (18:0) found in adults of baby corn fed larvae in male (40.97 ± 0.18) and castor fed larvae in female (42.10 ± 0.01). The monounsaturated fatty acids per cent were maximum in adults of castor fed larvae (61.48 ± 0.31) in male and baby corn fed larvae in female (56.64 ± 0.23). The highest pupal weight (0.22 ± 0.004 g), male (11.17 ± 0.32 days) and female (12.58 ± 0.28 days) longevity were observed in larvae fed on baby corn. The meridic diet proved as suitable host for rearing with highest gonadosomatic index (GSI) (36.97 ± 1.97), fecundity (1378 ± 70.50 eggs per female) and fertility (91.43 ± 0.71%). This study helps in understanding the effect of host nutrition on fatty acid content in fall armyworm in relation to its reproductive biology.