Comparative study on some Romanian and Bulgarian silkworm hybrids with the aim of their introduction in the family sericultural seed farms - I. Economical characters of the egg and larva.

SUMMARY The study was carried out to evaluate 19 Romanian and Bulgarian hybrids, with the aim of their introduction in the family sericultural seed farms. The experiment was made at experimental base of the Commercial Society “SERICAROM” S.A. – Research Department Baneasa. The hybrids evaluation for the economical characters specific in egg and larval stage pointed out, on the whole, the following values: 493-641 eggs/laying; 1815-1986 eggs/1 g; 262-335 mg weight of the laying; 35.0 – 42.55 layings/1 box silkworm seed; 93.3699.49% hatching percentage; 746-763 hours larval period; 92.48-96.88% pupation percentage. A high hatching percentage was determined in the hybrids: SK2/F x S8 (99.49%), AC/T x B1 (99.33%), AC/T x S8 (99.32%), V35 x M2 (98.90%), V2005 x V64 (98.58%). The high values of the pupation percentage have presented the following hybrids: B1 x AC/T (96.88%), AC/T x B1 (96.64%), AC29 x SK2/F (96.48%), V2003 x V2005 (96.44%), V35 x M2 (96.36).