Biological Pest Control and its Effectiveness

Biological Pest Control-Ckrokill

Biological pest control and its effectiveness enable people to understand the various ways they are beneficial to the plants and also the disadvantages of the method. Biocontrol or biological pest control is a means of preventing or regulating the population of unwanted insects, other species, or plants by taking their natural enemies to economically unimportant levels by adding, promoting, or artificially raising them. It is an important part of integrated pest management.

The biological pest control and weeds depend on parasitism, herbivory, predation, and other natural methods. Hence, it is the successful utilization of natural processes in helping human purposes, that function together well with nature. An effective biological pest control story refers to the capacity of human beings to portray natural processes for their use and can be the most harmless, and non-polluting form of control.

How is Pest Control Achieved by Biological Pest Control?

In biological pest control, the removal of the population of pests is done by utilizing the natural enemies purposely. Predatory and parasitoidal insects, predatory vertebrates, nematode parasites, protozoan parasites, and fungal, bacterial, and viral pathogens are natural enemies of pests, also known as biological control agents. Biological control agents of plant diseases are most widely termed as opponents. The biological control agents of weeds cover herbivores and plant pathogens.

Predators are mostly free-living animals that eat a large number of prey over their lifespans, such as lady beetles and lacewings. Parasitoids are species whose immature phase, grows on or inside a single insect host subsequently killing the host. The majority of them have a rather small host range.  Some flies are parasitoids and most of the species are wasps. Disease-causing species, including bacteria, fungi, and viruses, are normally pathogens. They kill their host and are reasonably particular to certain pests or weeds groups.

Strategies of Biological Pest Control Methods

There are three indispensable forms of biological pest control strategies:

Conservation Biocontrol

The preservation of existing natural enemies perhaps the most effective and easily accessible biological control activity available to homeowners and gardeners. Natural enemies exist in all fields, from the backyard garden to the commercial market. They are adapted to a specific atmosphere and to the target insect and are typically easy and cost-effective in their conservation. Snakes, for example, eat a lot of insects, rodents, and pests that can damage agricultural crops or carry diseases. Dragonflies are major mosquito consumers.

Eggs, larvae, and pupae, and Helicoverpa moths, the key insect pests of cotton, are all targeted by many beneficial insects, research can be carried out to classify vital habitats, supplies required to sustain them, and ways to encourage their development.

Lacewings, lady beetles, hover-fly larvae, and parasitized aphid mummies are often visible in aphid colonies. Fungus-infected adult flies are often usual following periods of high moisture. These naturally present biological controls are also exposed to the same pesticides used to kill their hosts. Simple conservation refers to the avoidance of unnecessary removal of natural enemies.

Classical Biological Pest Control

Classical Biological Pest Control-Ckrokill

Classical biological control is the introduction of unusual natural enemies to a new environment where they do not initiate or do not take place naturally. Typically, this is accomplished by government officials. In certain cases, the system of natural enemies connected with insect pests might become ineffective. This is particularly obvious when an insect pest is unintentionally introduced into a specific location, without its related natural enemies.

These established insects are known as foreign pests and make up about 40 percent of the United States’ insect pests. Examples of vegetable pests contain the European corn borer, one of North America’s most harmful insects. Scientists have used classical biological control to receive the necessary natural enemies. This is the method of introducing natural enemies for control of an introduced unusual pest and releasing them for development, although it is often performed against existing insect pests.

Determining the origin of the introduced pest is the first step in the process and then collecting suitable natural enemies identified with the pest or similar species. The natural enemy is then passed through a strict containment process to make sure that no harmful species such as hyperparasitoids or parasites of the parasite are added, and then produced in large quantities and released.

Studies are performed to assess if the natural enemy is finally established at the release zone and to examine the long-term value of its presence. Many examples of effective programs of classical biological control are available. The cotton cushion scale (Icerya purchasi), a pest destroyed the California citrus industry in the late 1800s, was one of the earliest achievements.

A destructive insect such as the Australian lady beetle or vedalia beetle (Rodolia cardinalis) and a parasitoid fly were introduced from Australia. The cotton cushion scale was fully dominated by these added natural enemies within a few years.

Damage from the alfalfa weevil, a dangerous introduced pest of crops, was greatly reduced by the introduction of many natural enemies, such as imported ichnemonid parasitoid Bathyplectes curculionis., the area of alfalfa treated for alfalfa weevil in the northeastern United States was reduced by 75 percent about twenty years after the introduction.

A small wasp, Trichogramma ostriniaeIntroduced from China to help manage the European maize borer (Pyrausta nubilalis), is a current example of a long tradition of classical biological control measures for this major pest. Many conventional biological control projects have been developed in the United States and Canada for insect pests and weeds.

Classical biological control is long enduring and low-priced. There is no expense sustained other than the initial costs of selection, importation, and rising. When a natural enemy is effectively-identified, extra input is rarely needed and the pest continues to be killed without direct human assistance and at no cost.

Classical biological control, sadly, does not always perform. Normally, it is most effective against insect pests and less so against insect pests that are native. The causes for failure are often unclear but might include the release of too few inhabitants, poor response of the natural enemy at the release location environmental conditions, and a shortage of harmony between the natural enemy’s life cycle and the host pest.

Augmentative Biological Pest Control

Augmentative Biological Pest Control-Ckrokill

This third biological control method requires the additional release of natural enemies. At a crucial time of the season, fairly few natural enemies can be released (inoculative release) or literally millions can be released (inundative release). In addition, the cropping method can be altered to support or increase natural enemies. This latter activity is sometimes referred to as the manipulation of habitat.

A form of inoculative release happens in the development of many crops in greenhouses. Periodic releases of the parasitoid, Encarsia formosa, are often used to regulate the greenhouse whitefly and the predaceous mite, Phytoseilus persimilis, is used to handle the two-spotted spider mite. The Encarsia formosa wasp lays its eggs in the young whitefly “scales,” making them black while the parasite larvae start growing. Preferably, it is implemented as quickly as possible once the first adult whitefly is identified,

It is most efficient when working with small level infestations, providing protection over a long period of time.  The predatory mite, Phytoseilus persimilis, is fairly larger than its prey, has an orange shell. It grows twice as quickly from egg to adult as the red spider mite and quickly overcomes infestation once developed.

Lady beetles, lacewings, or parasitoids such as Trichogramma are often distributed in large numbers (inundative release) and are sometimes referred to as biopesticides Depending on the degree of pest infestation, the suggested release rates for Trichogramma on vegetable or field crops vary from 5,000 to 200,000 per acre per week.

Likewise, for the control of some land-dwelling insect pests, entomoparasitic nematodes are released at rates of millions and even billions per acre. Metarhizium anisopliae var. Entomopathogenic Fungus Acridum has been established as an inundative biological control agent specific to species of short-horned grasshoppers (Acridoidea and Pyrgomorphoidea) widely spread in Africa.

Another type of augmentation is a habitat or environmental manipulation. To increase or boost the effectiveness of a natural enemy, this strategy includes changing the cropping method. Many adult parasitoids and predators gain from s sources of honey and the protection offered by hedgerows, cover crops, and weedy borders.

Combined plantings and the development of flowering borders will improve habitat diversity and provide shade and additional sources of food. They are fully converted into home gardens and even small-scale commercial plantings, but in large-scale crop production, they are more difficult to handle.

Owing to the difficulties of targeting the pest species and the use of nests by the pest insects as well as natural enemies, there may also be some controversy with the pest control for the large producer. Habitat manipulation involves increasing flowering plants (sources of pollen and nectar) around crops to draw and sustain natural enemy populations. For instance, hoverflies can be attracted to large arrays of plants in bloom.

The planting of prune trees in grape vineyards gives a primary grape pest parasitoid an increased overwintering habitat or shelter.

The prune trees are possible hosts for the parasitoid, which could formerly only overwinter at long distances from most vineyards. With this technique, precautions should be used because some plants that bring natural enemies can also be hosts for some plant diseases, particularly plant viruses that can be spread to the crop by insect pests.

While the strategy seems to carry a great deal of promise, only a few examples have been properly studied and produced.

Different Types of Biological Pest Control Agents



Ladybugs, and their larvae in particular, which are common in the northern hemisphere between May and July, are keen aphid predators such as greenflies and black fly, and may also eat mites, scale insects, and small caterpillars.

The ladybug is a very common beetle with different colored patterns, although its larvae are tiny and feathery at first, growing up to a length of 17 millimeters. The larvae have a narrow structured grey or black body with orange or yellow markings thorns in the garden and leave empty stems and some plant material over winter to allow them to hibernate over winter.

Hoverflies have distinctive hovering, leaping flight patterns, matching slightly with darker bees or wasps. There are about 100 species of hoverfly, the larvae of which feed mainly on the greenfly, a larva feeds up to 50 a day, or 1000 a day.

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Dragonflies are effective mosquito pests, both in the water where dragonfly naiads eat mosquito larvae, and in the air where adult dragonflies catch and eat adult mosquitoes. Community-wide mosquito control programs often destroy dragonflies by spraying adult mosquitoes, thereby removing an essential Biocontrol agent, which in the long term can probably improve mosquito populations.

The lacewings, pirate bugs, rove and ground beetles, aphid midge, centipedes, larger animals such as frogs, toads, lizards, hedgehogs, slow-worms, and birds are other useful garden predators. Field mice, rodents, June bugs, and birds are killed by cats and rat terriers. Dogs scare away many forms of unwanted species. Dachshunds are specifically designed to fit in underground tunnels to capture badgers.

They also take spider mites from the fruit tree, and small caterpillars. Adults live on nectar and pollen that they need for the development of eggs. Eggs are pale yellow-white, small (1 mm), and spread singly near colonies of greenflies.

Parasitoidal Insects

Parasitoidal Insects-Ckrokill

Parasitiods include a variety of insects that lay their eggs on or in an insect host’s body, which is then used as food to produce larvae. It takes parasitic wasps much longer to kill their targets than predators, and if the larvae had to feed too soon before they became adults, they would run out of food. In the organic garden, such parasites are very useful, since they are very good hunters, constantly at work, looking for pest attackers.

The important insect groups are:

Ichneumonid wasps – They are very small (5-10mm), eat the caterpillars of moths and butterflies.

Braconid wasps- Small wasps grow up to 5mm, they kill caterpillars and a huge range of other insects such as greenfly and a common parasite of the cabbage white caterpillar found in groups of sulfur-yellow cocoons. 

Chalcid wasps- These wasps are the smallest among all the other insects. They feed on eggs and larvae of greenfly, whitefly, cabbage caterpillars, scale insects, and strawberry tortrix moth.

Tachinid flies- live on a broad range of insects such as caterpillars, adult beetles and larvae, true bugs, and more.

Parasitic Nematodes

Parasitic Nematodes-Ckrokill

In addition to insects, nematodes victimize spiders, leeches, annelid, crustaceans, and mollusks. The black vine weevil in cranberries is an outstanding example of a situation in which a nematode can substitute chemicals to control an insect. The use of chemical insecticides on cranberries is either limited or the black vine weevil larvae have not been properly regulated. Many nematode-based products are presently obtainable.

Plants to Regulate Insect Pests

When you select a different array of plants for your garden will aid you to control pests in various ways, including,

•           Protects the crop plants from pests

•           Creates a smell that discourages pests

•           Acts as a trap plant to chase the pests away from crops

•           Serve as nursery plant for beneficial insects

Offering an adequate habitat where beneficial insects can live and grow, usually in the form of a shelterbelt, hedgerow, or beetle bank. Pollen-rich plants that grow for long durations are particularly good, during the adult stage; many beneficial plants are nectivorous, but parasitic or predatory as larvae. A perfect example of this is the soldier beetle, which is sometimes found as an adult on flowers but whose larvae eat aphids, caterpillars, grasshopper eggs, and other beetles.

The following are plants often used in vegetable gardens to stop insects:

Plant Targeted Pest
Thyme Cabbage worm.
Wormwood Animals from the garden.
Summer Savory Bean beetles.
Tansy Flying insects, Japanese beetles, striped cucumber beetles, squash bugs, and ants.
Sage Cabbage moth and carrot fly.
Southernwood Cabbage moth.
Peppermint White cabbage butterfly.
Rosemary Cabbage moth, bean beetles, and carrot fly.
Nasturtium Aphids, squash bugs, and striped pumpkin beetles.
Pot Marigold Asparagus beetles, tomato worm, and general garden pests.
Marigold Mexican bean beetles, nematodes, and others.
Mint White cabbage moth, and ants.
Garlic Japanese beetle.
Horseradish Potato bugs.
Basil Flies and mosquitoes.
Catnip Flea beetle.

Bio Pesticides

Bio Pesticides-Ckrokill

In controlling both pests and weeds, various bacterial species are commonly used. Bacillus thuringiensis, popularly called BT, is the well-known bacterial biological control that can be implemented to control butterfly caterpillars.

This is present in sachets of powdered spores, which are dispersed onto infected plants such as brassicas and fruit trees and combined with water. The endotoxin released and enabled in the midgut will kill the caterpillars upon intake of the bacterial preparation, but leave other insects untouched.

Easily visible viruses, namely NPV, cytoplasmic polyhedrosis (CPV), granulosis (GV), and entomopox viruses (EPN), are the viruses most commonly considered for insect control (usually in sawflies and Lepidoptera).

Fungi, like rodents and weeds, are infective agents of diverse species. This function is used thoroughly in biocontrol processes. Entomopathogenic fungi, such as Metarhizium anisopliae, Beauveria bassiana, and so on, allow the host to die from toxin production.

Significance of Biological Pest Control

Biological control agents are environmentally friendly and thus biologically healthy and appropriate. They are typically organisms unique to the targeted pests and weeds. The use of environmentally and agriculturally ineffective chemicals is prevented by biological regulation, which often contributes to the establishment of natural balance. There will be no issues with increased pest tolerance, as both biological control agents and pests are in a complex race of biological adaptability. Its control has been done by the use of bugs and beetles due to the chemical resistance produced by a particular beetle earlier. Biological control is economically very effective, even also where the technique has been less efficient.

Negative Effects of Biological Pest Control

Naturally, biological control appears to be self-regulating, but as environments are so diverse, all the effects of adding a biological controlling agent are difficult to foresee. Biological pest control may have unexpected negative results in certain situations, which may outdo all the advantages.

For example, when the mongoose was brought to Hawaii to control the population of rats, it killed Hawaii’s native birds, especially their eggs, more frequently than it fed on rats.

Likewise, the release of the cane toad to Australia 50 years ago to destroy a beetle that killed sugar beet has spread as a pest across eastern and northern Australia. It does have some Australian predators to monitor its population because the cane toad is poisonous.

Related Questions

1. What is the biological pest control of pest how is it beneficial?

A biological control refers to the favorable action of parasites, pathogens, and predators in controlling pest and their damage. Biocontrol offered by these species, jointly known as ‘natural enemies’ and is particularly essential for limiting the number of pest insects.

2. Is biological pest control effective?

In the long run, biological control can be cost-efficient. However, it might cost a little to launch new organisms into the atmosphere. It is a strategy that needs to be introduced once. Most importantly, it is very effective.

3. What are the advantages and disadvantages of biological pest control method?

This approach provides less risk of pollutants, biological control is more suitable for unusual pests that are not closely linked to natural beneficial organisms, biological control is inexpensive than chemical control. The biological control system is environmentally sustainable and safe.

4. What is the biological pest control of plant diseases?

Biological control is nothing but controlling the diseases by using biological agents to a host animal or plant which stops the growth of disease by a pathogen. The biocontrol means are usually bacterial or fungal strain separated from the endosphere or rhizosphere.

5. Is biological pest control more popular?

It is more difficult to use biological products in open fields or gardens because the farmer does not handle the climate as well and also it is not possible to control rainfall, humidity, and temperature. The plant is therefore more reachable to a variety of pests that may stop the growth of a particular biological control.

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