Have you ever wondered what a pest is? At what point does an animal or plant become a pest? The word " plague " is nothing more than an anthropic concept, at the moment in which an organism begins to compete against the human being and his interests, becomes a pest
Therefore, since the Egyptians, human beings have tried to stop these animals, either because they destroy our food or transmit diseases to us. In those moments biological pest control was born In this article on our site we will explain what biological pest control is, what types exist and why it is better than others pest eradication methods.
What is biological pest control?
In nature there are no pests. Pests are only found in systems modified by humans. In other natural systems, these pests would only be consuming animals. So, at what point does a species become a pest?
There are several reasons why an animal can become a pest:
- It may be that the pest species has been introduced or has invaded the region by its own methods. This is the case of exotic species that are not usually accompanied by their natural enemies.
- The existence of excessively abundant resources, such as a crop, can stimulate the proliferation of certain animals.
- The use of non-selective insecticides can cause the disappearance of predatory animals that kept insects under control that can become pests.
- A change or random mutation in the potentially pest species can make it invulnerable to its enemies.
- There may be changes in activities or habits of consumers.
Now that we know what a pest is, we will see what biological pest control is based on. This method has had different meanings throughout history. It is currently defined as an agricultural method that introduces natural predators, parasitoids or other natural strategies to control the pest, never to exterminate it 100% because it would imply the use of methods prohibited by law.
Biological pest control techniques
According to the bibliography, there could be several biological pest control methods. We will know the existing types according to Eilenberg et al.:
Classic biological control
Classic biological control consists of introducing and acclimating new species entomophagous, that is, they feed on arthropods. Generally, exotic predators of a pest of origin, also exotic, are introduced all at once. The new predator ends up acclimatizing to the system. Within this technique we find neoclassical biological control. In which exotic natural enemies are introduced against native pests, although this method is not recommended at all
In the classic biological control program, the useful fauna existing in the area where we have the problem is catalogued, since, sometimes, the native fauna is capable of controlling the exotic plague. In addition, the area of origin of the pest must be identified, since its natural enemies will be there.
Before applying the technique, a complete studyshould be carried out, establishing a quarantine zone, identifying the most interesting species. Afterward, you can breed natural enemies and drop them in the area. All under strict control and monitoring of the study.
Conservation biological control
With this technique, the aim is to modify the environment and manipulate the habitat to favor and enhance the activity of natural enemies. These natural enemies are already in the system and may be indigenous or introduced by previous strategies. In short, we try to preserve what we already have
Seasonal and inundative inoculative biological control
Using the seasonal inoculative strategy, biological control agents (predators) are introduced periodically, once or more times a year with the so that they multiply so that it is their descendants who end up controlling the plague, but without establishing it permanently. These agents must be bred en masse, so there are usually companies dedicated to it.
The inundative method follows the same strategy but predators are introduced massively. There is also an ethological control of pests that, through the use of pheromones and all its derivatives, use of attractants, repellents and feeding inhibitors, manage to control pests without the introduction of predators.
Biological control of pests and diseases
In certain cases, pests can cause diseases in other animals, such as humans, we are talking about zoonoses, diseases transmissible to the human being. A well-known pest that affects in this way are rats. In the 14th century, a massive infestation of rats throughout Europe caused the spread of the plague, through the fleas carried by the rats, causing millions of deaths.
In Ancient Egypt, already those humans used cats, highly revered animals, to keep rodents under control, since outside to prevent grain reserves from being eaten and to avoid the appearance of certain diseases, although at that time the existence of microorganisms harmful to humans was not yet known.
Biological pest control and its examples
To finish, we will see some examples of predatory animals capable of controlling pests:
- Ladybugs or coccinellids are predators of aphid pests.
- Lacewings or mayflies feed on a wide variety of pest insects, such as aphids or leaf miners.
- Centipedes feed on many pest insects, they are also active at night, so they prey on animals other than those they diurnal predators feed.
- Nests of the ant (Oecophylla smaragdina) to regulate the population of stink bugs (Tessaratoma papillosa) in citrus.
- Some hemiptera or bugs such as Orius tristicolor or Podisus nigrispinus prey on butterfly larvae, thrips or leaf eaters.
Great care must be taken when applying biological pest control, carrying out preliminary studies and carrying out exhaustive monitoring. There are cases in which the controlling agent became a pest, such as what happened in the 17th century with the common myna, Acridotheres tristis, a bird from India, which was introduced to Mauritius to control populations of the red lobster, Nomadacris septemfasciata. Today, myna is a plague.
