Dynamics of Nutritional Indices in Fifth Instar Silkworm Bombyx Mori L. Parasitized with Beauveria Bassiana

Abstract

Silkworm Bombyx mori is a small economically significant insect. Due to domestication for centuries, silkworms have become very gentle and subtle to the environmental conditions and   micro-pathological agents which affect its metabolism, the food intake, dietary utilization, dietary efficiency, morpho-nutritional parameters such as olfactory organs and gene expression in the silkworm. Hence, the present research was focused to comprehend the dynamic changes in the nutritional parameters amalgamating the effects of infection of Beauveria bassiana in 5^th instar silkworm compared to untreated silkworms. For the current investigation, the popular silkworm race bivoltine double hybrid (CSR2 X CSR27) X (CSR6 X CSR 26) was chosen. Various nutritional parameters such as ingestion of mulberry leaf, digestion, excretion, approximate digestibility, consumption index and reference ratio were estimated based on the dry weight of mulberry. The results indicated that food consumption, digestion of food ingested and excreta decreased in Beauveria bassiana parasitized silkworms. No significant variation was noticed in approximate digestibility and reference ratio from the first day to the fifth day of the instar, but on the sixth day, a significant drop in these two parameters was noticed compared to unparasitized worms. The consumption index was recorded higher in the experimental batch.