柞丝产量不稳定的原因与种质变劣、病害抬头、鳥、兽害和其他虫害有关,但主要原因是寄生蝇为害。寄生蝇有数种,其普遍发生、为害严重的,首推梳脛寄蝇(Blepharipoda Schineri Mesnil)。 辽宁省寄生蝇为害情况,据已有調查資料,一九五六年以前,在柞蚕主要产区,寄生蝇为害較少,一九五七年后种群数量逐年 The causes of unstable production of tussah silk and germplasm deterioration, disease rise, birds, animal and other pests and insect pests, but the main reason is parasitic fly harm. There are several kinds of parasitic flies, which are common and devastating, with the exception of Blepharipoda Schineri Mesnil. According to the survey data, before 1956, there was less damage to parasitic flies in the tussah main producing areas. After 1957, the number of pests per year has been increasing year by year