Once a biological control agent is released, it is difficult to control its speed.

一旦实施了生物控制手段，它的速度就很难控制。

Legal consequences of attempts at biological control present a potential minefield.

尝试进行生物防治的法律后果是一个潜在的雷区。

How effectively biological control can be pressed into service is proved by the following examples.

下面的例子证明了生物防治如何能有效地投入使用。

According to law, the release of the biological control agents must be authorized by the secretary of state for the environment.

根据法律规定，发放生物控制剂必须得到环境国务秘书的批准。

Of course, biological control agents can safely be released only if it can be verified that they feed solely on the target weed.

当然，只有能够证明它们仅以目标杂草为食，生物控制剂才能安全释放。

The advantage of biological control in contrast to other methods is that it provides a relatively low-cost, perpetual control system with a minimum of detrimental side-effects.

与其他方法相比，生物防治的优点是它提供了一种成本相对较低、有害副作用最小的永久性防治系统。

In fact, scientists already have much of the information needed to assess the impact of biological control of bracken, but it is spread among many individuals, organizations, and government bodies.

事实上，科学家已经掌握了评估生物控制蕨类植物的影响所需要的大量信息，但是这些信息在许多个人、组织和政府机构中传播开来。

Biological control has been used in many parts of the world.

生物防治曾经在世界许多地方使用。

Research progress of the biological control for lymantria dispar l.

舞毒蛾生物防治研究进展。

The problems of biological control in the tea ecosystem is discussed.

讨论了茶园生物防治有待于进一步探讨的问题。

This chapter is spent on three classic case of successful biological control.

本章着重于生物防治的三个成功的经典例子。

Chitinase and glucanase are very important in plant disease biological control.

几丁质酶和葡聚糖酶在植物病害生物防治作用中具有重要的作用。

It is an effective method of biological control to use insect virus to prevent pest.

利用昆虫病毒防治害虫是生物防治的一种有效方法。

Biological control is a promising approach to reduce the storage diseases of jujube fruit.

生物防治是控制枣果采后病害的研究新方向。

Natural enemies, especially species of Torymidae, are considered as efficient biological control agents.

它有许多天敌，尤其是长尾小蜂，被认为是有效的生物防治手段。

Egg parasitoids of the genus Trichogramma are widely used in biological control against Lepidopterous pests.

赤眼蜂属是生物防治中广泛用来防治鳞翅目害虫的一类重要天敌昆虫。

The results of this paper have practical significance on pest prediction and on biological control experience.

本文的研究对害虫测报和生防工作具有实际意义。

Application of Nosema locustae to control Chondracris rosea is an effective and promising biological control method.

应用蝗虫微孢子虫防治棉蝗，是一种有效而很有前途的生物防治方法。

So it is with the science of biological control in its modern sense. in american it had its obscure beginnings a century ago.

现代的生物控制论就是如此。一百年前，这门学科在美国开始创立时也是隐隐约约的。

The use of biological control technology for water purification is emerging in the world, and this technique is a breakthrough.

利用生物调控技术对水体进行净化是正在当今世界兴起的一种突破性的水体修复技术。

Forestry pests is a serious problem in Hunan, while the researching and exploiting biological control products are not optimistic now.

湖南林业有害生物发生形势严峻，而有害生物天敌产品的研究与开发现状不容乐观。

This paper deals with a detailed review on the species, biology, ecology and their effect on biological control of aphid hyperparasitoids.

对蚜虫重寄生蜂的种类、生物学特性、生态学特性及蚜虫重寄生蜂对生物防治的影响进行了较详细的综述。

Among the 10 strains, 6 strains have no inhibiting effects on one another. They may be mix used in biological control of bacterial wilt of tobacco.

对该10个菌株相互之间的拮抗性测定结果表明，有6个菌株相互之间无拮抗作用，可在烟草青枯病的生物防治中应用。

Yet animals like sheep or goats eat weeds, so they can provide a biological control. Insects and other organisms can also act as biological controls.

然而，像绵羊或山羊之类的动物会吃杂草，因此它们可以起到生物控制作用。昆虫和其他生物也可以起到生物控制作用。

In this paper predator-prey systems with periodic impulsive effect concerning pest control are proposed through biological control and chemical control.

摘要本文通过生物控制和化学控制提出了具有周期脉冲效应与害虫控制的捕食系统。

Objective To provide morphological data of appendicular muscle for further research on the biological control systems of GekkogeckoSs motional function.

目的为研究大壁虎运动及其生物控制提供附肢肌的定量形态资料。