REARING PERFORMANCES OF ERI (Philosamia ricini) AND MULBERRY (Bombyx mori) SILKWORM STRAINS AND DISEASES INCIDENCE AT BERE SERICULTURE, ARBA MINCH, ETHIOPIA

Abstract

This study evaluated the performance of five eri (Bere, Cross, EKPR, EKSCR, India) and five mulberry (China-2, Kenya-2, Kenya-3, Kenya-4, Korea-1) silkworm strains and observe the level of diseases incidence on farmer management condition in between March and May 2018, in Arba Minch. The experiment was laid out in Completely Randomized Design (CRD) with five replications. The study revealed that mature larvae of eri silkworm strains significantly varied on nutritional indices and strains Bere, Cross, and India displayed better performances. The silkworm strain India showed greater fresh weight basis feed utilization and had 18.2g ingesta, 12.83g digest, 32.9% approximate digestibility, 3.33 feed consumption index and, 0.28g relative growth rate in the fifth instar on daily basis. Similarly, China-2, Kernya-2, and Kenya-4 of bivoltine mulberry silkworm strains showed greater performances on feed utilization, China-2 was superior with 3.28g consumption, 1.27g utilization, 38.04% approximate digestibility, and 1.89 feed consumption index. Eri silkworm India demonstrated greater economic traits with 353 eggs/moth in fecundity, 81% hatchability, 6.28g larval weight, and 97.77% survival rate. It had weights of 3.07g cocoon, 0.52g shell, 2.25g pupa, and 17.17% silk ratio. The mulberry silkworm strains China-2, Kenya-2 and Kenya-4 had 520, 560, 526 fecundity, 89, 88, 90 hatchability, 2.31, 2.30, 2.39g larval weight, 99, 99, 98 survival rates, respectively. The mulberry silkworm strain China-2 scored the highest on cocoon traits with weights of 1.37g, 0.23g, 1.14g, cocoon, shell, and pupa, respectively, and silk ratio of 17.01%. The rearing facility at Bere was conducive for silkworm rearing, production (cocoons and seed) and no symptoms of diseases and pebrine spores were observed. Out of the ten strains subjected to multiple economic traits evaluation six strains namely, India, Cross, Bere, China-2, Kenya-2, Kenya-4 scored cumulative evaluation index values >50 and classified as eligible strains which possess greater economic value. Most of the results on the performances of silkworm stains found in this study were comparable and, in some cases, better than the studies made so far in Ethiopia and other countries. Silkworm strains China-2 (mulberry) and India (eri) appeared as the most promising with respect to rearing performances and cocoons traits, followed by the strains of Bere, Cross, Kenya-2, and Kenya-4. Finally, similar studies are recommended to be made in different seasons, places, and years. Future studies on the evaluations of strains should include rearing at different levels, including conditions of low-income farmers, to be able to select and recommend the best-fit strains to different rearing setups