Across the American continents, exotic species are those introduced after the first European contact.

在美洲大陆上，外来物种是在第一次与欧洲人的接触后引进的。

Both native and exotic species can become invasive, and so they all have to be monitored and controlled when they begin to get out of hand.

本土物种和外来物种都有可能成为入侵物种，因此当它们开始失控时，我们必须对它们进行监视和控制。

According to the facts that we know, (1) D. simulans is an exotic species;

根据了解到的事实，（1）拟果蝇在中国是一个外来种；

The exotic species has caused problems for the shrimping industry in other parts of the world.

这些外来物种给世界其他地方的虾业带来困扰。

When importing a lot of exotic species, we should not forget to conserve local breed resources.

在大量引进外种的情况下，应当不忘记把地方的品种资源保存好。