Foliage to Fiber: Decoding the Nutritional efficiency and assimilation of different hosts on growth, reproduction and silk production of Samia ricini (Donovan) (Lepidoptera: Saturniidae)

Abstract

Abstract Food consumption and conversion efficiency of eri silkworm Samia ricini (Donovan) were studied on castor, tapioca, and kesseru. Growth rate, consumption, and assimilation of food in five larval instars were analyzed. The total larval duration comprising five instar stages were found to complete in 18.33 ± 0.41, 19.92 ± 0.38, and 21.00 ± 0.45 days on castor, tapioca, and kesseru respectively. The ingesta recorded was significantly higher on the primary host castor (34.89 ± 1.15 g) as compared to tapioca (30.35 ± 0.94 g) and kesseru (29.49 ± 1.16g). The tissue growth rate was recorded on par for the first four instars on the three hosts studied. However, fifth-instar weight gain showed significant differences among the hosts. During the fifth instar, high feeding and assimilation rates were recorded in all the hosts studied, to meet the high energy demands of metabolic processes involved in synthesizing and spinning the cocoon as a protection for the succeeding non-feeding pupal stage. The single cocoon weight, pupal weight, and shell weight were found to be superior on castor, followed by tapioca and kesseru. However, the shell ratio percentage was found to be on par for all three hosts. The successful reproductive phase of the non-feeding adult stage was also dependent on the food energy accumulation during the larval stage. The reproductive phase study of the emerged adults reared on three hosts revealed that the effective egg production was on par on all three hosts.