Good evening.

晚上好。

I'm here today to present the findings from our research into pesticides and alternatives to using them.

我今天在这里要介绍我们关于杀虫剂及其替代品的研究成果。

I'd like to begin by talking about some of the environment effects of pesticide use.

我想先谈谈使用杀虫剂对环境的一些影响。

As most of you will be aware, pesticides have proven to be very harmful to our environment.

正如你们大多数人所知，杀虫剂已被证明对我们的环境非常有害。

The principal reason for this is because nearly all pesticides along water channels such as rivers, where they are then transported downstream.

主要原因在于，几乎所有杀虫剂都会沿着河流等水道流动，然后被输送到下游。

In order situations, particularly when they are dropped by plane,

在其他情况下，尤其是当它们由飞机喷洒时，

the wind blows pesticides into wild areas where they are not wanted. These areas can be up to several kilometers away.

风会把杀虫剂吹到并不需要它们的野外区域。这些区域可能远在数公里之外。

We also need to think about the effects of pesticides on animals.

我们还需要考虑杀虫剂对动物的影响。

Pesticides can cause illness and even death in many animals, including birds and aquatic life.

杀虫剂会导致许多动物患病甚至死亡，包括鸟类和水生生物。

Animals can also be affected, however, when pesticide use eliminates their food source and causes them to starve or migrate to other areas.

然而，当使用杀虫剂消除了动物的食物来源，导致它们挨饿或迁徙到其他地区时，动物也会受到影响。

When pesticides don't travel into neighbouring environments,

当杀虫剂没有扩散到邻近环境时，

they tend to seep into the soil.

它们往往会渗入土壤。

There they degrade the quality of the soil and in addition, they can weaken biodiversity -studies of pesticide - contaminated soil show a much lower count of organisms compared to healthy soil.

在那里，它们会降低土壤质量，此外还会削弱生物多样性——对被杀虫剂污染的土壤的研究显示，其生物数量远低于健康土壤。

There's a final consideration to take into account,

还有最后一点需要考虑，

and that's the environmental effects of pesticides in terms of pest numbers.

那就是杀虫剂在害虫数量方面对环境的影响。

In the short term, pesticides significantly reduce the number of pests in an area, as might be expected.

短期内，杀虫剂会显著减少某个地区的害虫数量，这也在意料之中。

After long-term, regular use, however, insects tend to become immune to certain kinds of pesticide and are no longer negatively affected by them.

然而，在长期、定期使用之后，昆虫往往会对某些杀虫剂产生免疫力，不再受其负面影响。

As the number of insecticide resistant pests grows, this creates the need for new varieties of pesticide,

随着抗杀虫剂害虫数量的增加，就产生了对新型杀虫剂的需求，

and further exacerbates the pesticide problem.

并进一步加剧了杀虫剂问题。

Let's move on now to look at some possible alternatives to pesticide use.

现在让我们来看看一些可能的杀虫剂替代方案。

As l' II explain, although these techniques can help reduce our dependence on pesticides,

正如我将要说明的，尽管这些技术有助于减少我们对杀虫剂的依赖，

they do have their own drawbacks too.

但它们也有自身的缺点。

The first technique will be familiar to any of you who have even a small vegetable garden at home.

第一种技术，对任何在家里哪怕只有一小块菜园的人来说都不陌生。

You see a slug on a piece of lettuce,

你看到一片生菜上有一只鼻涕虫，

and what do you do? Put on some gloves, walk right up to the plant and pick the slug off with your hands.

你会怎么做？戴上手套，径直走到植物前，用手把鼻涕虫摘下来。

This is called handpicking.

这叫做人工捕捉。

Handpicking is remarkably effective and requires little in the way of money to implement.

人工捕捉非常有效，而且实施起来几乎不需要花钱。

But while it may be sufficient for the home gardener,

但虽然这对家庭园丁来说可能足够了，

the time-consuming nature of handpicking makes it unsuitable for large-scale operations.

人工捕捉耗时的特点使其不适合大规模作业。

Owners of larger crops and orchards require a more systematic approach to pest management,

拥有较大规模农作物和果园的人需要更系统的害虫管理方法，

and they have a few options here.

他们有几个选择。

You may be familiar with a technique known as biological control.

你可能熟悉一种叫作生物防治的技术。

This involves the strategic use of what we call 'good'insects - that is,

这涉及策略性地使用我们所说的“益虫”——也就是，

insects which eat pests, rather than plants. When they eat the pests,

吃害虫而不是吃植物的昆虫。当它们吃掉害虫时，

they also protect the crop environment.

它们也保护了作物环境。

Unfortunately, biological control is always risky because we can never know for sure how insects will behave in a particular environment,

遗憾的是，生物防治总是有风险的，因为我们永远无法确定昆虫在特定环境中会如何活动，

and the results are therefore unpredictable.

因此结果也难以预测。

A safer option is companion planting,

一个更安全的选择是伴生种植，

where certain plants are grown together.

即把某些植物种在一起。

Garlic, for example, fends off spider mites and aphids,

例如，大蒜能驱除红蜘蛛和蚜虫，

and basil drives away the tomato hornworm,

而罗勒能驱走番茄天蛾幼虫，

making it a good companion for tomatoes.

使它成为番茄的好伴侣。

This is because some varieties of plant can repel specific breeds of insects,

这是因为某些植物品种能驱避特定种类的昆虫，

so planning them alongside and around more vulnerable vegetables will discourage the insects from coming near.

所以把它们种在更脆弱的蔬菜旁边和周围，就能阻止昆虫靠近。

Of course, all these extra plants begin fighting for space and

当然，所有这些额外的植物开始争夺空间，

competing with the protected plants for access to water

并与受保护的植物争夺水分

and nutrients in the soil.

和土壤中的养分。

A final possibility is crop rotation. This involves alternating plants every harvest,

最后一个可能是轮作。这涉及每次收获后轮换植物，

which forces insects to migrate in an attempt to locate their food source.

这迫使昆虫迁徙，以寻找它们的食物来源。

Crop rotation is unappealing for large-scale commercial operations, however, because the high cost of constantly changing crops cuts into their profits.

然而，轮作对大规模商业种植缺乏吸引力，因为不断更换作物的高成本会削减他们的利润。

As you can see, there's still no easy answer to the question of how to keep plants free from the scourge of pests.

如你所见，如何让植物免受虫害之苦，这个问题仍然没有简单的答案。

I'm happy to take any questions...

我很乐意回答任何问题……