BIOLOGICAL CONTROL OF PEST
1. BIOLOGICAL CONTROL IS A PEST MANAGEMENT STRATEGY THAT USES NATURAL ENEMIES, LIKE PREDATORS, PARASITOIDS, OR
PATHOGENS, TO SUPPRESS PEST POPULATIONS. IT’S AN ENVIRONMENTALLY FRIENDLY APPROACH THAT CAN HELP REDUCE RELIANCE
ON SYNTHETIC CHEMICALS AND MAINTAIN BALANCED ECOSYSTEM
2. IT RELIES ON PREDATION, PARASITISM, HERBIVORY, OR OTHER NATURAL MECHANISMS, BUT TYPICALLY ALSO INVOLVES AN ACTIVE
HUMAN MANAGEMENT ROLE. IT CAN BE AN IMPORTANT COMPONENT OF INTEGRATED PEST MANAGEMENT (IPM) PROGRAMS
3. PREDATORS: INSECTS THAT CONSUME OTHER INSECTS, LIKE LADYBUGS THAT EAT APHIDS.
4. PARASITOIDS: INSECTS THAT LAY THEIR EGGS INSIDE OR ON OTHER INSECTS, LIKE PARASITOID WASPS THAT TARGET CORN BORERS.
5. PATHOGENS:VIRUSES, BACTERIA, FUNGI, AND NEMATODES THAT CAUSE DISEASES IN PESTS, LIKE BACILLUS THURINGIENSIS (BT), A
BACTERIUM THAT IS TOXIC TO CERTAIN INSECT LARVAE.
6. MICROBIAL AGENTS: MICROORGANISMS THAT CAN CONTROL PEST POPULATIONS THROUGH VARIOUS MECHANISMS, LIKE
COMPETITION, ANTIBIOSIS, OR PARASITISM.
HISTORY OF BIOCONTROL
• The history of biological control spans millennia, from ancient examples of using animals for pest
control to the modern scientific approach
• Early examples include using cats for rodent control in ancient Egypt and Chinese growers
employing ants to control citrus pests
• The 19th century saw the development of more organized biological control methods, and the
term “biological control” was formally introduced in 1919
• Biological control techniques began to emerge, with entomologists like C.V. Riley and W.L.
Howard in the US exploring natural enemies of pest
CONT….
• The USDA initiated its first large-scale biological control program, sending entomologists to Europe and Japan to
find natural enemies of the spongy moth and brown-tail moth
• The term “biological control” was first used by Harry Scott Smith at a meeting of the American Association of
Economic Entomologist
• Continued research focuses on understanding the interactions between natural enemies and pests, developing new
biological control agents, and improving the effectiveness of biological control programs.
SCOPE OF BIOLOGICAL PEST CONTROL
• Pest Types:
• Biological control is applied to a wide range of pests, including insects, mites, weeds, nematodes, and even
vertebrate pests.
• Environments:
• It’s used in various settings, such as agriculture, forests, urban areas, aquatic environments, and even stored
products.
• Integrated Pest Management (IPM):
• Biological control is a crucial component of IPM, a holistic approach to pest management that combines
various techniques to minimize pest damage while reducing environmental impact.
SCOPE
• Species Specificity:
• Biological control agents are often very specific to their target pests, minimizing harm to beneficial
organisms and the broader ecosystem.
• Sustainable Control:
• Biological control aims for long-term and sustainable pest suppression, reducing reliance on synthetic
pesticides and their potential negative consequences.
• Research and Development:
• Ongoing research and development are crucial for identifying new biological control agents,
understanding their biology and ecology, and optimizing their use in various environments.
CLASSICAL BIOLOGICAL CONTROL
• Classical biocontrol is a pest management strategy that involves introducing natural
enemies (like predators, parasitoids, or pathogens) from the pest’s native habitat to
control it in an area where it’s become an introduced, invasive, or exotic species
• The goal is to establish a self-sustaining population of the natural enemy to permanently
suppress the pest population
• Examples:
• The introduction of the Australian lady beetle to North America to control cottony
cushion scale is a classic example
CONT…
• What it is:
• Classical biocontrol focuses on using natural enemies from the pest’s original home to control it in a new
location.
• Why it’s used:
• Invasive pests often thrive in new environments because their natural enemies are not present, leading to
unchecked population growth.
• How it works:
• Researchers identify natural enemies of the pest in its native habitat, study their host specificity (to
ensure they only target the target pest), and then release them into the new area to establish a self-
sustaining population.
CONSERVATION BIOLOGICAL CONTROL
• Conservation biological control is a strategy in pest management that focuses on
enhancing the effectiveness and presence of natural enemies (such as predators,
parasitoids, or pathogens) already present in the environment, rather than introducing
new ones
• Planting nectar-producing flowers to support parasitoid wasps
• Leaving strips of natural vegetation near crops to serve as refuges for predators like lady
beetles or lacewings
CONT…
• Protect Existing Natural Enemies:
• Avoid practices (e.g., broad-spectrum pesticides) that harm beneficial organisms.
• Enhance Habitat:
• Provide food, shelter, and alternative prey or hosts to support natural enemy populations. This can include
planting flowering plants, maintaining hedgerows, or reducing tillage
• Reduce Disturbance:
• Minimize agricultural practices that disrupt natural enemy populations and habitats
• Encourage Biodiversity:
• Promote a diverse agroecosystem to support a wider range of natural enemies and ecological balance.
AUGMENTATIVE BIOLOGICAL CONTROL
• Augmentative biological control is a pest control strategy that involves releasing additional natural enemies, like predators
or parasites, into an area to increase their population and improve pest control. It’s like boosting the “natural police force”
to control a pest outbreak.
• This approach is particularly useful when natural enemy populations are too low to effectively control pests.
• Types of releases:
• Inoculative releases: Small numbers of natural enemies are released to establish a population and control pests throughout
the season.
• Inundative releases: Large numbers of natural enemies are released to quickly suppress a pest population, often in response
to a sudden outbreak
