A parasite called microsporidia lies dormant in the circulatory systems of harlequin ladybirds.

这种叫做“子”寄生潜藏在小丑瓢环系统内。

When the ladybugs were injected with dead microsporidia or a control substance most survived.

当植入死子或者对照物质时，大多数都存活了。

But when scientists injected microsporidia into a common European ladybug species, the insects died within two weeks.

然而，当科学家向普通欧洲瓢体内植入子时，不出两个星期它们就死亡了。

When European ladybug species eat the harlequin ladybird eggs and larvae, they also consume the microsporidia. And die.

当欧洲瓢吃小丑瓢卵和幼同时，也吃掉了子。然后它们就会死。