Studies on factors biasing the primary sex ratio toward females in the oriental tea tortrix, Homona magnanima (Lepidoptera : Trotricidae)

在日本茨城筑波的东方茶蛾中发现了雌性偏向性比例（鳞翅目：茶蛾科）。全雌株与正常株的平均卵孵化量无显著差异。在全雌株幼虫中观察到超过50%的死亡率，这表明雌株幼虫是由于雄株后期杀死而产生的。雌性偏向的性别比例是母系遗传和维持的，甚至当雌性与正常品系的雄性回交时也是如此，因此暗示细胞质寄生是其原因。这种现象在抗生素存在的情况下持续存在，并不是由于引起其他雄性死亡现象的病原体的感染，如立克次体、沃尔巴克氏体、螺旋体或原生动物寄生虫。将全雌株雄虫死亡幼虫的匀浆接种到正常株幼虫中，这种杀雄性状遗传给下一代；因此，其病原体也可能是水平传播的。

A female-biased sex ratio was found in the oriental tea tortrix, Homona magnanima (Lepidoptera : Tortricidae), in Tsukuba, Ibaraki, Japan. There was no difference in mean egg hatch between the all-female and normal strains. Greater than 50% mortality was observed in the all-female strain larvae, suggesting that female-only broods are produced as a result of late male-killing. The female-biased sex ratio was maternally inherited and maintained, even when females were backcrossed with males of the normal strain, thus implicating cytoplasmic parasitism as its cause. The phenomenon was persistent in the presence of antibiotics, and was not due to infection by agents that cause other male-killing phenomena, such as Rickettsia, Wolbachia, Spiroplasma, or protozoan parasites. When a homogenate of dead male larvae of the all-female strain was inoculated in normal strain larvae, this male-killing trait was transmitted to the next generation ; thus, its causative agent is likely transmitted horizontally as well.