Biological Control (Lec. 5)
The primary function of a biological control
quarantine facility is to provide a secure area where
the identity of all incoming biological control
candidates can be confirmed and undesirable
organisms, especially hyperparasitoids, parasitoids of
predators, and extraneous host or host plant material,
can be eliminated. In fact, the quarantine laboratory
often represents the last chance to study and evaluate
potential biological control agents in the sequence of
collection, importation and liberation.
Quarantine and Exclusion
The Philippines, being an agricultural country, faces threats
from invasive pests that could severely affect crops like
rice, corn, and fruits.
Quarantine facilities in the country ensure that these
biological control agents, often imported from abroad, are
properly identified, screened, and studied before being
released into the local ecosystem. This prevents the
accidental introduction of harmful organisms that could
disrupt native species and agricultural productivity.
Role of Quarantine Facilities
As seen in the United States and other countries, the
Philippines could benefit from expanding its quarantine
capacity. With the global increase in biological control as a
preferred alternative to chemical pesticides, the Philippines
will need more advanced quarantine laboratories to assess
the safety of imported biological control agents.
Expansion of Quarantine Facilities
The Philippines also faces strict regulations
surrounding the importation and release of
biological control agents. Compliance with
both domestic and international regulations
can slow down the process of introducing
beneficial organisms into the country.
As air travel becomes more common,
unpredictability in shipment routes and
inspection delays at customs can result in
dead or weakened biological material upon
arrival, making quarantine facilities even
more essential for reviving and testing these agents.
Regulatory and Logistical Challenges
The Philippines' unique and rich biodiversity requires extra caution
when releasing non-native biological control agents. Any imported
biological agent must undergo rigorous testing to ensure it does not pose a
threat to the local ecosystem. Prolonged quarantine periods, however,
could alter the biological control agent's fitness, potentially reducing its
effectiveness. To avoid such risks, it is crucial to increase quarantine
capacity and speed up the regulatory process. The Philippines can also
explore conducting pre-release studies in the country of origin to reduce
the risk of genetic changes and delays in effectiveness.
Environmental and Genetic Considerations
The Philippines has had notable success in using
biological control to manage pests, such as the introduction
of parasitoids to control coconut pests like the coconut leaf
beetle. Expanding this practice can help reduce dependence
on chemical pesticides, which can harm the environment
and human health. As environmental awareness grows,
adopting more biological control methods would align with
the country's goals for sustainable agriculture.
Importance of Biological Control in the
Philippines
which affects herbivores directly through
physical or chemical means, such as thorns, toxins,
digestibility reducers.
Direct Defense
which
promotes the effectiveness of carnivores (Dicke, 1999).
Indirect defense
Plants are bred to naturally
resist pests by either repelling them, harming them, or
tolerating their damage.
Host Plant Resistance
Natural enemies (like predators and
parasites) are encouraged to reduce pest populations. This
can involve conserving local predators, releasing extra
ones, or introducing a predator from another place.
Biological Control
After harvest, plants should
be destroyed to kill pests and remove their food source. Removing
weeds like Johnsongrass, which attracts pests, also helps reduce
pest populations.
Crop Destruction and Host Removal
Growing in rotation with non-host crops (like cotton
or soybeans) can prevent pests from building up. This is effective
against pests that only survive on certain crops and can’t move easily
between fields.
Crop Rotation
Selecting pest-resistant varieties and
preparing good seedbeds helps prevent pest damage. Earlymaturing varieties can avoid peak pest times, and resistant varieties
can prevent disease spread by pests.
Choosing Resistant Varieties
Planting early in the season allows the crop to
grow past vulnerable stages before pests increase in number.
This helps avoid infestations of pests (e.g., in sorghum, like the
sorghum midge and corn earworm).
Planting Time
Proper fertilizer and
water use can strengthen plants, making them more resilient to
pests. However, overuse can make plants more attractive to
pests and delay maturity, leaving them vulnerable longer.
Fertilizer and Water Management
Protecting natural enemies (such as lacewings, ladybugs,
and birds) is key. By avoiding harmful pesticides and encouraging natural
food sources, we can help these beneficial species thrive and keep pests
in check. For instance, birds that eat insects can be attracted by planting
native plants or installing birdhouses.
Conservation
In pest control, natural enemies (like
predators, parasites, and beneficial insects) help manage pests without
chemicals.
Conservation and Augmentation
Sometimes, releasing additional natural enemies is
necessary. This can involve releasing small numbers (inoculative) at the
right time or large numbers (inundative) to control pests. For example,
releasing ladybugs or parasitic wasps helps reduce pest populations in
fields and greenhouses.
Augmentation
Adjusting the environment to support
natural enemies can also help. Adding nectar plants or
shelters (like flowerpots with straw) encourages these
beneficial species to stay and protect crops. In some cases,
plants are added to attract predators or provide
overwintering sites. However, some plants might also attract
pests or diseases, so careful selection is needed
Habitat Manipulation
It is s a pest control strategy that
combines different methods to manage pests safely and sustainably
IPM
IPM focuses on controlling pests, not eliminating
them entirely, which is costly and harmful to the environment. Action
thresholds are set to decide when pest levels are high enough to require
action.
Acceptable Pest Levels
Using strong, healthy plant varieties and proper
sanitation (like removing diseased plants) helps prevent pest problems.
Preventive Practices
Regularly observing pest levels is crucial. Tools like traps or
visual checks help determine pest presence, and knowing their life cycles
helps time controls effectively
Monitoring
If pest levels exceed acceptable limits,
mechanical methods like hand-picking, barriers, and traps are used
before considering other options.
Mechanical Controls
Encouraging beneficial insects that eat pests or
using natural pesticides helps keep pest populations in check with
minimal impact on the environment.
Biological Controls
After applying controls, assessing the results is essential to
understand what worked and what didn’t, allowing for improvements in
future IPM strategies.
Evaluation
combines knowledge and various techniques to manage pests,
making it useful in both organic farming and conventional agriculture
to reduce chemical use, costs, and environmental impact.
IPM
It is a structured
approach to manage pests in an efficient, sustainable way. It applies
to various settings, from farms to home gardens, reducing harmful
chemical use and costs while promoting environmental safety
IPM
Properly identify the pest to avoid ineffective
actions. Misidentifying pests, like mistaking water damage for a fungal
issue, can lead to unnecessary and ineffective treatments.
Identify the Pest
Learn about the pest’s life
cycle and survival needs. This knowledge helps time interventions
correctly, like using mulch to prevent weeds from sprouting.
Understand Pest Biology and Life Cycle
Regularly observe pest populations to prevent
outbreaks. Monitoring tools, like sticky traps for roaches, help detect
pests early and keep track of their distribution and numbers.
Monitor Pest Levels
Determine acceptable pest levels. For
example, some pest damage may be tolerable, but action is needed
when pest damage is costlier than control measures.
Set Action Thresholds
Use a mix of methods, like mechanical
(e.g., hand-picking), cultural (e.g., removing diseased plants),
biological (e.g., encouraging natural predators), and chemical (e.g.,
botanical pesticides) controls to manage pests effectively.
Choose Control Methods
Assess the effectiveness of the IPM approach.
Review questions like, "Did it work as expected?" and "Were there any
side effects?" to improve future IPM strategies.
Evaluate Results