Growth, consumption and digestive enzyme activities of Spodoptera littoralis (Boisd) on various mung bean cultivars reveal potential tolerance traits

Abstract

AbstractSpodoptera littoralis (Boisd) is a worldwide pest of economic importance for agricultural crops. We investigated nutritional efficiency and digestive enzyme activity of S. littoralis on various mung bean cultivars, including Parto, Simite1, Simite2, VC6173A, VC3960, VC6368 and VC6371. Furthermore, various biochemical traits of mung bean cultivars, including protein, starch, total phenolic and flavonoid content, were measured to investigate their relationships with nutritional physiology of S. littoralis. The nutritional indices, as well as proteolytic and amylolytic activities of S. littoralis were significantly affected by feeding of the pest on various mung bean cultivars. Larvae reared on VC6371 exhibited the highest efficiency of conversion of digested food, while the lowest was recorded in those fed on Simite2. Spodoptera littoralis larvae fed on the Simite1 cultivar exhibited the lowest relative growth rate, while those reared on Simite2 were characterized by the lowest efficiency of conversion of ingested food. The highest proteolytic activity of sixth‐instar larvae was on VC6371, while the lowest activity was on VC3960, Simite1 and Simite2 cultivars. Amylolytic activity was the lowest in those larvae fed on VC6368 and VC6371 cultivars, while the highest activity occurred in larvae reared on Simite2. Significant variation in phytochemical contents was quantified among tested mung bean cultivars. Moreover, significant correlations were found between the nutritional indices and digestive enzyme activities of S. littoralis with biochemical properties of the cultivars. Our results suggest that VC6371 is a suitable cultivar for S littoralis, while Simite2 and Simite1 cultivars are less suitable and may be useful selections to minimize damage caused by this pest.