Determination of Optimal Temperature for Production of Quality Eri Silkworm Cocoon and Seed

Abstract

Agro-ecological variables play a crucial role in performance of eri silkworm cocoon production and seed selection. The main intention of the experiment was to evaluate effects of temperature on cocoon, pupa and cocoon shell weight to identify an optimum temperature for improved silk production and quality seed preparation. Four filial generations of yellow plain Eri silkworm types were used to study the effects of temperature on cocoon production at Bere Sericulture Production PLC in Arba Minch, Ethiopia. Four temperature gradients, 20 °C, 25 °C, 30 °C and 35 °C, were used with ten replications. The cocoon weight scores and egg hatchability data were subjected to statistical analysis at P<0.05 using R version 3.4.3. Mean separation was conducted using least significant difference (LSD) at P<0.05 using the package “agricolae” in R. It was observed that temperature gradient significantly affected (P<0.001) cocoon, pupa, cocoon shell weight, egg number and hatchability of the eggs. The potential egg hatchability and cocoon production were obtained at 25 °C. The promising production can be obtained at temperature range of 25-30 °C. Filial generations had no effect on pupa, cocoon shell weight, egg number and hatchability of the eggs, except on cocoon (P<0.05). The present study therefore suggests that the ideal eri silkworm rearing temperature ranged from 23 °C up to 30 °C