(Week 1 & 2)
IDENTIFY PESTS AND THEIR
NATURAL ENEMIES ACCORDING
SYMPTOMS AND STAGE OF
(Pest Management 12)
Direction: Observe the following pictures and answer the processing questions
WHAT IS THIS WORKSHEET ALL ABOUT?
This unit covers the skills, knowledge and attitude required to apply
physical-control measures for pests, in line with the IPM strategy. It includes
identifying the target pests and their natural enemies, and other beneficial
organisms, selecting the physical control activities and preparing for their
implementation, implementing the control activities and checking the
performance of the control activities.
LET’S TRY THIS! (Explore)
Note: Motivation Activity
2. Processing Questions:
1. What have you observed in the pictures?
2. What do you think is the cause of plant damage?
3. What are the best things to do to prevent pest damage to plants?
What is Pest
A pest is an organism living and growing where they are not wanted and can
cause damage to plants, humans, structures, and other creatures, including crops
that are grown for food. Integrated pest management is when different controls
methods are used to manage pests, including chemical controls, which must be
used responsibly by farmers on crops and by adults around the home.
What is Natural Enemies
The natural enemies of plant pests are considered as farmers' friends. Various
beneficial organisms that can help the farmer to keep pests (and some
diseases)under control and prevent them from causing economic damage.
Areas of land which have not been cultivated or disturbed contain hundreds or
thousands of species which tend to form a balance, with each of them depending
on some of the others. Although large outbreaks of plant-eating pests do
sometimes occur in natural systems, any one particular species is less likely to
build up a large population if the organisms which feed on it are also present - in
other words, its natural enemies.
Predators > are one type of natural enemies which tend to keep the population of
their prey in check. They catch and eat other insects and mites, including pest
species. Parasitoids are another type of natural enemies. They lay eggs in or on
other species of insect (called hosts) and the larval stage kills the host as it feeds
on it and develops. The third major group of farmers' friends is pathogens. These
are fatal or debilitating diseases to arthropod pests and include fungi, nematodes,
bacteria, viruses, and other microbes. Fungi, particularly Deuteromycetes, can
infect pests externally under favorable conditions, but other pathogens must be
ingested to be effective as control agents. Pathogens are very specific to their
hosts. Pathogens can be used as biopesticides because they can be applied in
similar ways to chemical interventions.
Beneficial living organisms which reduce pests and diseases are usually present in
any crop unless broad spectrum pesticides (which kill a wide range of arthropods)
have been used. These so-called natural enemies can be conserved by taking
care with farming practices so that they are not killed or are actually encouraged. If
numbers of such biocontrol agents are still not sufficient to keep pests at
acceptable levels, it is possible to release additional beneficial organisms of the
same type - a process known as augmentation or inundation. Farmers who collect
ladybird beetles in field margins and release them on their crop are
LET’S LEARN! (Learn)
o gather, interpret and convey information in response
to workplace requirements.
3. practicing augmentation. Alternatively, if suitable types of beneficial organisms are
not present in the crop, theycan be introduced. Where introductioninvolves a local
beneficial organism, which has simply not yet reached a particular crop, this is
known as inoculation. If the introduced beneficial organism is from outside the
area (typically from the country or area where the troublesome pest originated) and
becomes established as the controlling factor for the pest in the new area, it is
known as classical biological control. A new balance is created so that the pest
becomes less important.
THE TYPES OF NATURAL ENEMIES
These are organisms that prey and feed on other organisms. They often
feed on various stages of the host (pest): eggs, larvae, pupae and adult.
Each predator kills and feed on a number of prey individuals during their
development (larvae to adult). Most adults are also predators.
For example: ladybird beetles, dragonflies, predatory mites, predatory
bugs, predatory wasps and spiders.
Organisms that during the larval stages feed on pests (external parasitoids)
or in the pest (internal parasitoids). They complete their development on a
single host, killing it. In their adult stages they are mostly free-living (with
few exceptions) and feed on pollen and nectar or other sugary substances
such as honeydew.
The most common parasitoids are parasitic wasps and flies.
Organisms that can cause diseases of pests. They include fungi, bacteria,
viruses and nematodes. They can be important in controlling pest
populations in agricultural systems. However, naturally occurring
pathogens often are too rare to serve as important control agents or occur
when the damage has already been done.
Some pathogens such as the bacterium Bacillus thuringiensis (Bt) and
the fungus Trichoderma viride are commercially available in many
countries, including Kenya.
Other fungi such as Zoophthora, Verticillium and Entomophthora can be
readily found in the field at particular times of the year, infecting aphids,
beetles, caterpillars, grasshoppers and whiteflies.
4. Life Cycle of Insect Pests
History of Pests and Their Management
Pests, defined as an insects and other organisms that threaten crops,
livestock, pets and people, have threatened civilization throughout history,
necessitated the use of chemicals for pest control, and caused the need for the
awareness of their potential environmental impacts. This awareness has
influenced an evolution toward a more integrated pest management approach that
includes the use of pesticides. Diseases of humans and agricultural crops spread
by pests have made significant, and often negative, impacts upon society. The
need to manage them with chemicals and other controls shows the importance of
pest management systems in society. The first section of this document reviews
situations when pests caused significant impact in society including death, famine,
economic loss and new discoveries and management strategies. Next, historical
pest control methods will be discussed. Finally, integrated pest management will
PEST CONTROL IN HISTORY
Since the beginning of time, pest control has been vital to the health and
longevity of human existence. Records of natural pest control date back to 2500
BC, thousands of years after the beginning of agriculture began in the Fertile
Crescent of Mesopotamia. Sulfur, also known as brimstone, was the earliest
documented substance used as a pesticide. Its first known use was by pagan
priests who used it as medicines, fumigants, bleaching agents and incense in
religious rights. The Romans used sulfur, from the fumes from combustion, as an
insecticide, to purify a sick room, and to clean the air from evil. In 1000 BC, the
same uses of sulfur were reported by Homer in the Odyssey. Today, there are
more than 50 sulfur products registered for use as pesticides in Florida alone,
primarily used for arthropod control in a wide variety of crops.
5. WHAT CAN YOU DO? (Engage)
Direction: Let the students identify the different damage of plants and
characterized pest that cause the said damage. Select your answer from the box
below that correspond the said damage of plants.
Direction: Answer the following question
1. Let the students come up an explanation based on observation on
how a particular pest damage to plants according to general
classification/lifecycle and behavior/signs and symptoms and stage
of growth. (you can refer your observation through internet/video or
on your actual field observation).
LET’S SEE WHAT YOU HAVE LEARNED (APPLY)
Note: This is the evaluation and application of learning.
Stem borer locust cutworm armyworm